JP2017069461A - Manufacturing method of stepped substrate, manufacturing method of electronic device, and laminate - Google Patents

Abstract

To provide a method for manufacturing a stepped substrate capable of easily and accurately transferring a mask pattern having a multistage structure without repeating processes including a photolithography process and an etching process. A method of manufacturing a stepped substrate having a pattern having a multi-step recessed portion whose width gradually decreases in the depth direction, comprising: (a) a substrate, a first processing target layer, an etching stopper; A mask pattern having a multi-stage concave portion whose width decreases stepwise in the depth direction on a multilayer substrate in which a layer and a second processing target layer are laminated in this order, Forming a mask layer having a mask pattern composed of at least a first recess having a lowest width and a second recess being an upper stage of the first recess; and (b) A method of manufacturing a stepped substrate, comprising: etching the laminated substrate using a mask layer as a mask, and transferring the shape of the mask pattern. [Selection] Figure 3

Description

  The present invention relates to a method for manufacturing a stepped substrate, a method for manufacturing an electronic device including the same, and a laminate that can be suitably used in the method for manufacturing the stepped substrate. More specifically, the present invention relates to a semiconductor manufacturing process such as an IC (Integrated Circuit), a circuit board such as a liquid crystal and a thermal head, a manufacturing process such as a MEMS (Micro Electro Mechanical System), and other photofabrication. The present invention relates to a step substrate manufacturing method suitable for the lithography process, an electronic device manufacturing method including the same, and a laminate that can be suitably used in the step substrate manufacturing method.

  With the recent diversification and higher functionality of electronic devices, it is required to form a specific fine three-dimensional structure pattern on a substrate. As an example of a structure having a three-dimensional structure pattern, there is a stepped substrate having a fine pattern having a multi-stage structure (hereinafter also referred to as “multi-stage structure pattern”). As a method for manufacturing a stepped substrate having a multistage structure pattern, for example, there is a method for manufacturing a stepped substrate having a dual damascene structure. As a method for manufacturing a stepped substrate, as shown in the background art of Patent Document 1 and FIGS. 1 to 5 and Patent Document 3, a method including a photolithography process → an etching process is repeated at least twice. Met.

  Recently, with regard to the technology for manufacturing a stepped substrate having a multi-step structure pattern, the substrate to be processed is collectively etched after forming a multi-step mask pattern for the purpose of reducing costs by reducing the number of processes and reducing alignment errors. Thus, a method of forming a multi-stage structure pattern that can simplify the number of steps and improve alignment accuracy has been proposed (see, for example, Patent Documents 1 and 2).

JP 2007-173826 A Special table 2007-521645 gazette JP 2002-299441 A

  As a result of studies by the present inventors, according to the above technique, it is possible to reduce the number of steps necessary for manufacturing a stepped substrate having a multi-step structure pattern, but it is difficult to transfer a mask pattern with high accuracy. It turns out that. In the prior art including the above technique, the etching process after the formation of the mask having the multi-stage structure pattern has not been studied in detail, and the present inventors have tried the etching process using the mask having the multi-stage structure pattern. As a result, the shape of the multi-stage mask pattern is deteriorated, such as the shoulder drop at the corners of the multi-stage structure in the layer to be processed, dimensional variations, and variations in the processing depth during etching. It became clear that it could not be transferred to.

  The present invention has been developed in view of such circumstances, and is a stepped substrate capable of easily and accurately transferring a multi-stage mask pattern without repeating processes including a photolithography process and an etching process. It is an object to provide a manufacturing method. Another object of the present invention is to provide a method for manufacturing an electronic device including the method for manufacturing a stepped substrate, and a laminate that can be suitably used for the method for manufacturing the stepped substrate.

In one aspect, the present invention is as follows.
[1] A method for manufacturing a stepped substrate having a pattern including a multi-stage recess having a width that gradually decreases in the depth direction,
(A) A multi-stage structure in which a width is gradually reduced in a depth direction on a laminated substrate in which a substrate, a first processing target layer, an etching stopper layer, and a second processing target layer are stacked in this order. A mask pattern comprising at least a first recess having a lowest width and a second recess being an upper stage of the first recess. A step of forming a mask layer having, and (b) a step of etching the laminated substrate using the mask layer as a mask to transfer the shape of the mask pattern,
A method for manufacturing a stepped substrate including:

[2] The step (a) of forming a mask layer having the mask pattern includes:
(I) forming a first negative pattern having a first recess on the laminated substrate; and
(Ii) forming a second negative pattern having a second recess on the first negative pattern;
Including
The step (i)
(I-1) forming a first film on the laminated substrate using the actinic ray-sensitive or radiation-sensitive resin composition (1);
(I-2) a step of exposing the first film, and (i-3) a step of developing the exposed first film using a first developer,
Including
The step (ii)
(Ii-1) forming a second film on the first negative pattern using the actinic ray-sensitive or radiation-sensitive resin composition (2);
(Ii-2) exposing the second film, and
(Ii-3) developing the exposed second film using a second developer,
The method for manufacturing a stepped substrate according to [1], including:

  [3] The actinic ray-sensitive or radiation-sensitive resin composition (1) is a composition containing a resin whose polarity increases by the action of an acid and whose solubility in a developer containing an organic solvent decreases. [2] A method for manufacturing a stepped substrate according to [2].

  [4] The method for manufacturing a stepped substrate according to [2] or [3], wherein the first developer is a developer containing an organic solvent.

  [5] The actinic ray-sensitive or radiation-sensitive resin composition (2) is a composition containing a resin whose polarity increases by the action of an acid and whose solubility in a developer containing an organic solvent decreases. [2] The method for manufacturing a stepped substrate according to any one of [4].

  [6] The method for manufacturing a stepped substrate according to any one of [2] to [5], wherein the second developer is a developer containing an organic solvent.

  [7] The method for manufacturing a stepped substrate according to any one of [2] to [6], further including a heating step between the step (i) and the step (ii).

  [8] Any one of [2] to [7], wherein the actinic ray-sensitive or radiation-sensitive resin composition (1) is different from the actinic ray-sensitive or radiation-sensitive resin composition (2). 2. A method for manufacturing a stepped substrate according to item 1.

  [9] Any of [2] to [7], wherein the actinic ray sensitive or radiation sensitive resin composition (1) and the actinic ray sensitive or radiation sensitive resin composition (2) are the same composition. 2. A method for manufacturing a stepped substrate according to claim 1.

  [10] An imprint method using a mold having a pattern having a multi-stage projecting portion in which the step (a) of forming a mask layer having the mask pattern has a stepwise decreasing width from the bottom to the top. The method for manufacturing a stepped substrate according to [1], including forming the mask pattern by:

[11] An etching process step (b) for transferring the shape of the mask pattern,
(B1) a step of transferring the shape of the first recess to the second processing target layer by the first etching;
(B2) transferring the shape of the first recess to the etching stopper layer by second etching;
(B3) transferring the shape of the first recess to the first processing target layer by the third etching; and (b4) transferring the shape of the second recess to the second processing target layer by the fourth etching. The manufacturing method of the level | step difference board | substrate of any one of [1]-[10] including the process to carry out.

  [12] The method for manufacturing a stepped substrate according to [11], wherein the step (b3) and the step (b4) are performed simultaneously.

  [13] The method for manufacturing a stepped substrate according to [11] or [12], wherein the step (b1) and the step (b2) are collectively performed under the same etching conditions.

  [14] When a layer is interposed between the first recess in the mask layer and the laminated substrate, a step of transferring the shape of the first recess to the layer by etching is further performed before the step (b1). The method for manufacturing a stepped substrate according to any one of [11] to [13].

  [15] The method for manufacturing a stepped substrate according to any one of [1] to [16], wherein the stepped substrate having a pattern provided with a recess having a multistage structure is a stepped substrate having a dual damascene structure.

  [16] A method for manufacturing an electronic device, including the method for manufacturing a stepped substrate according to any one of [1] to [15].

  [17] A multi-stage structure having a width that decreases stepwise in the depth direction on a stacked substrate in which the substrate, the first processing target layer, the etching stopper layer, and the second processing target layer are stacked in this order. The laminated body which comprises the mask layer which has a mask pattern provided with the recessed part.

  According to the present invention, it is possible to provide a method for manufacturing a stepped substrate capable of easily and accurately transferring a mask pattern having a multistage structure without repeating a process including a photolithography process and an etching process. In addition, according to the present invention, it is possible to provide a method for manufacturing an electronic device including the method for manufacturing a stepped substrate and a laminate that can be suitably used for the method for manufacturing the stepped substrate.

FIG. 1A is a cross-sectional view schematically showing one embodiment of the laminate of the present invention. FIG. 1B is a cross-sectional view schematically showing one embodiment of the laminate of the present invention. FIG. 1C is a cross-sectional view schematically showing one embodiment of the laminate of the present invention. 2A to 2E are schematic perspective views for explaining a method for manufacturing a stepped substrate according to an embodiment of the present invention. 3A to 3E are schematic cross-sectional views for explaining a method for manufacturing a stepped substrate according to an embodiment of the present invention. 4A to 4I are schematic cross-sectional views for explaining a method for manufacturing a stepped substrate according to an embodiment of the present invention. 5A to 5H are schematic cross-sectional views for explaining a method for manufacturing a stepped substrate according to an embodiment of the present invention. FIGS. 6A to 6G are schematic cross-sectional views for explaining a method for manufacturing a stepped substrate according to an embodiment of the present invention. FIGS. 7A to 7I are schematic cross-sectional views for explaining the method of manufacturing the step substrate according to the first embodiment. FIGS. 8A to 8H are schematic cross-sectional views for explaining a method for manufacturing a stepped substrate according to the second embodiment. FIGS. 9A to 9G are schematic cross-sectional views for explaining a method for manufacturing a stepped substrate according to the third embodiment. 10A to 10G are schematic cross-sectional views for explaining a method for manufacturing a stepped substrate according to Comparative Example 1, respectively. FIGS. 11A to 11E are schematic cross-sectional views for explaining evaluation criteria in Examples and Comparative Examples, respectively.

  In the description of the group (atomic group) in this specification, the notation which does not describe substitution and non-substitution includes the thing which has a substituent with the thing which does not have a substituent. For example, the “alkyl group” includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).

  In addition, “active light” or “radiation” in the present specification refers to, for example, an emission line spectrum of a mercury lamp, a far ultraviolet ray represented by an excimer laser, an extreme ultra violet (EUV) ray, an X ray or an electron beam ( Electron Beam (EB). In the present invention, “light” means actinic rays or radiation.

In addition, the term “exposure” in the present specification is not limited to exposure with far-ultraviolet rays such as mercury lamps and excimer lasers, X-rays and EUV light, but also with particle beams such as electron beams and ion beams, unless otherwise specified. Include in drawing 3082 exposure.
Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1A, 1B, 1C, and 2 to 6.

  In this specification, for example, the term “mask layer 120” simply means all of the mask layers 120A to 120G or any one selected from the mask layers 120A to 120G unless otherwise specified. The same applies to other components.

  The method for manufacturing a stepped substrate according to the present invention (hereinafter referred to as “the manufacturing method of the present invention”) is a method for manufacturing a stepped substrate having a pattern having a recess having a multistage structure whose width decreases stepwise in the depth direction. The method includes the following steps: (a) forming a mask layer on the laminated substrate; and (b) transferring the shape of the mask pattern to the laminated substrate by etching.

  Step (a): A multi-stage structure in which the width gradually decreases in the depth direction on the laminated substrate in which the first processing target layer, the etching stopper layer, and the second processing target layer are stacked in this order. A mask pattern comprising at least a first recess having a lowest width and a second recess being an upper stage of the first recess. Forming a mask layer.

  Step (b): A step of transferring the shape of the mask pattern by etching the laminated substrate using the mask layer obtained in the step (a) as a mask.

  The following description will be divided into a process (a) for forming a mask layer on the multilayer substrate and an etching process (b) for transferring the shape of the mask pattern to the multilayer substrate.

<< Step (a): Step of Forming Mask Layer on Laminated Substrate >>
The mask layer formed in the step (a) has a mask pattern having a multi-stage recess having a width that decreases stepwise in the depth direction (hereinafter referred to as “mask pattern having a multi-stage structure”, “multi-stage structure”). Also referred to as a “mask pattern”. The mask layer having the multistage structure mask pattern is formed on the laminated substrate.

  In the present invention, forming a mask layer on a multilayer substrate means that a mask layer is formed directly on the surface of the multilayer substrate without any other layer, and a mask layer is formed on the multilayer substrate via another layer. It is meant to include both forms.

  Examples of the case where another layer is interposed include a case where a lower layer such as an antireflection film is interposed between the laminated substrate and the mask layer, as will be described later.

<Laminated substrate>
The multilayer substrate includes at least a substrate, a first processing target layer, an etching stopper layer, and a second processing target layer, and these three layers are stacked in the order described.

The manufacturing method of the present invention is characterized in that the laminated substrate to be processed has a layer structure in which an etching stopper layer is interposed between two layers to be processed. By interposing the etching stopper layer, it is possible to suppress the shoulder drop at the corners of the processing target layer and the dimensional variation, so that the multi-stage mask pattern can be transferred to the processing target layer with high accuracy. The manufacturing method of the present invention is further characterized in that the laminated substrate is subjected to an etching process using a multistage mask pattern described later as a mask. In order to control the thickness of the two layers to be processed, a technique for interposing an etching stopper layer between the two layers to be processed is known, but an etching processing technique using an etching stopper layer and a multistage structure mask pattern is known. It has been found for the first time by the present inventors that the shape of the mask pattern having a multi-stage structure can be transferred easily and with high accuracy by the combination.
The material of the first and second processing target layers is not particularly limited. For example, in the case of interlayer insulation processing of a semiconductor device, an organic insulating film, hydrogen silsesquioxane, a carbon-containing SiO ₂ film (SiOC), a porous silica film, a polymer film, an amorphous carbon film (F-doped), SiOF , SiO _{2 and the} like. These layers to be processed are etched under fluorine gas plasma conditions or nitrogen / hydrogen gas plasma conditions in an etching process step (b) described later.

  Further, the combination of materials of the first and second processing target layers is not particularly limited. For example, different material qualities may be combined, or the same kind of material may be selected.

The material of the etching stopper layer is not particularly limited, and a material that can take an etching selectivity as appropriate can be selected according to the material of the processing target layer and the etching conditions. For example, SiC, SiN, SiOC, SiCN, and silicon compounds such as SiO _2, Cr, Al, Ni, Cu , Ti, Au, Pt, Pd, Ta, alloys containing Mo or the like or oxides, nitrides Can be mentioned. These etching stopper layers are etched under a fluorine-based gas condition or a chlorine-based gas condition in an etching process step (b) described later.

The film thickness of the etching stopper layer is determined by the film thickness of the processing target layer and the selection ratio with the processing target layer at the time of etching, but is usually in the range of 10 nm to 100 nm.
As still another form of the laminated substrate, an etching stopper layer (hereinafter referred to as “second etching stopper layer”) may be further provided between the substrate and the first processing target layer. Good. In this embodiment, the etching stopper layer interposed between the first processing target layer and the second processing target layer is referred to as a “first etching stopper layer”.

As another form of the laminated substrate, there are other layers such as a transistor layer and a wiring layer between the substrate and the first processing target layer, or between the substrate and the second etching stopper layer. Here, the shape, structure, material and size of the substrate are not particularly limited, and can be appropriately selected according to the purpose. As the material of the substrate, for example, a commonly used substrate such as Si, SiC, GaN, glass, sapphire, or the like can be used. As thickness of the said board | substrate, 0.05 mm or more is preferable, for example, and 0.1 mm or more is more preferable.
<Laminated body>
[Laminate 100A]
As one form of a laminate (hereinafter referred to as “laminate of the present invention”) in which a mask layer having a multistage structure mask pattern is formed on a laminate substrate obtained in step (a), the laminate shown in FIG. 1A is used. The body 100A is mentioned. The stacked body 100A includes a mask layer 120A on the stacked substrate 110A.

  In the multilayer substrate 110A, the substrate 3A, the second etching stopper layer 2A, the first processing target layer 20A, the first etching stopper layer 1A, and the second processing target layer 30A are stacked in this order. Here, the second etching stopper layer 2A is an arbitrary constituent member.

  The mask layer 120A is formed by, for example, a patterning method such as a photolithography method described later, and has a first pattern 40A having the first recess 11A and a width wider than the first recess 11A formed thereon. It has a mask pattern including a multi-stage recess 10A composed of a second pattern 50A including a wide second recess 12A.

[Laminate 100B]
Moreover, the laminated body 100B as described in FIG. 1B is mentioned as another form of the laminated body of this invention. This laminated body 100B shows an example in which an arbitrary constituent member such as a lower layer film is interposed between the laminated substrate and the mask layer, and the antireflection layer 60B is interposed on the laminated substrate 110B. A mask layer 120B.

  In the multilayer substrate 110B, the substrate 3B, the second etching stopper layer 2B, the first processing target layer 20B, the first etching stopper layer 1B, and the second processing target layer 30B are stacked in this order. Here, the second etching stopper layer 2B is an arbitrary constituent member.

  The mask layer 120B is formed by, for example, a patterning method such as a photolithography method described later, and has a first pattern 40B having the first recess 11B and a width wider than the first recess 11B formed thereon. It has a mask pattern provided with a multistage recess 10B composed of a second pattern 50B provided with a wide second recess 12B.

  As an underlayer film that can be interposed between the laminated substrate 110 and the mask layer 120, an antireflection film such as an organic antireflection film or an inorganic antireflection film, or the like can be appropriately selected. The underlayer film material is available from Brewer Science, Nissan Chemical Industries, Ltd. Examples of the lower layer film suitable for the process of developing using a developer containing an organic solvent include the lower layer film described in International Publication No. 2012/039337.

[Laminate 100C]
Further, as another embodiment of the laminate of the present invention, a laminate 100C illustrated in FIG. 1C can be given. The stacked body 100C includes a mask layer 120C on the stacked substrate 110C.

  In the multilayer substrate 110C, the substrate 3C, the second etching stopper layer 2C, the first processing target layer 20C, the first etching stopper layer 1C, and the second processing target layer 30C are stacked in this order. Here, the second etching stopper layer 2C is an arbitrary constituent member.

  The mask layer 120C is formed, for example, by a patterning method such as an imprint method to be described later, and is formed on the first recess 11C and the first recess 11C, and has a second width wider than the first recess 11C. And a mask layer 120 </ b> C having a mask pattern provided with a multi-stage concave portion 10 </ b> C composed of the concave portions 12 </ b> C. The mask layer 120C has a remaining film layer 70C below the recess 10C.

In the production method of the present invention, the method for forming the mask layer in the step (a) is not limited, and can be formed by, for example, a photolithography method, an imprint method, or the like. First, a method for forming a mask layer using a photolithography method will be described.
<Mask Layer Formation Step by Photolithography (a1)>
When the formation of the mask layer having a multistage structure mask pattern in the step (a) is performed by photolithography, the step (a) includes the following step (i) and step (ii) (step (a1 )).

[Step (i)]
Step (i) is a step of forming a first negative pattern having a first recess, and includes the following steps (i-1), (i-2), and (i-3).

(I-1) forming a first film on the laminated substrate using the actinic ray-sensitive or radiation-sensitive resin composition (1);
(I-2) exposing the first film, and
(I-3) A step of developing the exposed first film using a first developer.

[Step (ii)]
Step (ii) is a step of forming a second negative pattern having a second recess on the first negative pattern, and the following steps (ii-1) and (ii-2) And (ii-3).

(Ii-1) forming a second film on the first negative pattern using the actinic ray-sensitive or radiation-sensitive resin composition (2);
(Ii-2) exposing the second film, and
(Ii-3) A step of developing the exposed second film using a second developer.

  The reason why the mask pattern having a multistage structure can be easily formed by the mask layer forming step (a1) by the photolithography described above is estimated as follows.

  First, the step (a1) includes at least two times of patterning, that is, patterning by the step (i) and patterning by the step (ii).

  Here, since the second negative pattern formed by the step (ii) is obtained from the second film formed on the first negative pattern formed by the step (i), the first negative pattern is obtained. The size and shape of the negative pattern and the size and shape of the second negative pattern can be designed independently of each other.

  Therefore, for example, a pattern having a multistage structure in which a line pattern (second negative pattern) is stacked on a hole pattern (first negative pattern) can be formed.

  Further, according to the manufacturing method of the present invention including the step (a1) of forming the mask layer, the mask layer having the obtained multistage structure pattern is masked without repeating the process including the photolithography step → the etching step. As a result, it is possible to perform batch etching on the object to be processed.

  In steps (i) and (ii), a film is formed using an actinic ray-sensitive or radiation-sensitive resin composition containing a cross-linking agent, and after exposure, the unexposed area is dissolved with an alkali developer. It may be a step of forming a mold pattern, or contains a resin whose polarity is increased by the action of an acid and its solubility in a developer containing an organic solvent (hereinafter also referred to as “organic developer”) decreases. The step of forming a negative pattern using the actinic ray-sensitive or radiation-sensitive resin composition to be used and utilizing the difference in dissolution rate in the organic developer between the exposed area and the unexposed area. In the former case of using an alkaline developer, the exposed portion made of a crosslinked product is easily swollen by the alkaline developer, and it may be difficult to form a fine pattern. The latter using an organic developer is preferred.

  In the step (a1) by the photolithography method, each of the step (i) and the step (ii) can be performed by a generally known method.

  Hereinafter, an embodiment of the mask layer forming step (a1) by photolithography will be described with reference to FIGS.

2A to 2E are schematic perspective views for explaining a method of manufacturing a stepped substrate according to an embodiment of the present invention, in which FIGS. 2A to 2D are illustrated. FIG. 5 is a schematic perspective view for explaining one form of a step (a1) for forming a mask layer by photolithography. 3A to 3E are schematic cross-sectional views for explaining a method for manufacturing a stepped substrate according to an embodiment of the present invention, in which FIGS. ) Are schematic cross-sectional views for describing one mode of the step (a1) of forming a mask layer by a photolithography method.
[Step (i): Formation of First Negative Pattern]
In the present embodiment described based on FIGS. 2 and 3, the above steps (i-1), (i-2), and (i-3) are performed in this order, so that a row is formed on the multilayer substrate 110D. A first pattern 40D ′ (hole pattern) having a plurality of hole portions (first concave portions 11D) arranged at equal intervals in the direction and the column direction is formed (FIGS. 2A and 3A). ).

  Hereinafter, the steps (i-1), (i-2) and (i-3) will be described in detail.

-Step (i-1): Formation of first film-
In the step (i-1), a first film is formed on the multilayer substrate 110D using the actinic ray-sensitive or radiation-sensitive resin composition (1). In the laminated substrate 110D, the substrate 3D, the second etching stopper layer 2D, the first processing target layer 20D, the second etching stopper layer 1D, and the second processing target layer 30D are stacked in this order.

  In the step (i-1), the method of forming the first film using the actinic ray-sensitive or radiation-sensitive resin composition (1) is typically an actinic ray-sensitive or radiation-sensitive resin composition. This can be carried out by applying the product (1) onto the laminated substrate 110D. As the coating method, a conventionally known spin coating method, spray method, roller coating method, dipping method or the like can be used, and preferably the spin coating method. Apply the actinic ray-sensitive or radiation-sensitive resin composition (1).

  The actinic ray-sensitive or radiation-sensitive resin composition (1) will be described later in detail.

  The thickness of the first film is preferably 20 to 1500 nm, more preferably 50 to 1500 nm, and still more preferably 60 to 1500 nm.

  In particular, when a light source having a wavelength of 1 to 200 nm (specifically, an ArF excimer laser described later) is used, the thickness of the first film is preferably 20 to 160 nm, and preferably 50 to 140 nm. More preferably, it is more preferably 60 to 120 nm.

  When a light source having a wavelength of more than 200 nm and not more than 250 nm (specifically, a KrF excimer laser described later) is used, the thickness of the first film is preferably 200 to 1500 nm, and preferably 300 to 1200 nm. It is more preferable that it is 300-1000 nm.

-Pre-heating step and post-exposure heating step-
It is also preferable that the step (i) includes a preheating step (PB; Prebake) between the step (i-1) and the step (i-2).

  The step (i) preferably includes a post-exposure heating step (PEB; Post Exposure Bake) between the step (i-2) and the step (i-3).

  The heating temperature is preferably 70 to 130 ° C., more preferably 80 to 120 ° C. for both PB and PEB.

  The heating time is preferably 30 to 300 seconds, more preferably 30 to 180 seconds, and still more preferably 30 to 90 seconds.

  Heating can be performed by means provided in a normal exposure / developing machine, and may be performed using a hot plate or the like.

  The reaction of the exposed part is promoted by baking, and the sensitivity and pattern profile are improved.

  At least one of the preheating step and the post-exposure heating step may include a plurality of heating steps.

-Step (i-2): Exposure of first film-
In step (i-2), the exposed first film is obtained by exposing the first film.

In the exposure of step (i-2), the wavelength of the light source used in the exposure apparatus is not limited, but examples include infrared light, visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light, X-rays, and electron beams. In particular, far ultraviolet light having a wavelength of 250 nm or less, more preferably 220 nm or less, particularly preferably 1 to 200 nm, specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157 nm), X-ray, EUV (13 nm), electron beam, and the like, preferably KrF excimer laser, ArF excimer laser, EUV or electron beam.

  Step (i-2) may include a plurality of exposure steps.

  For example, when the light source is a KrF excimer laser, an ArF excimer laser, or EUV, it is preferable to irradiate (that is, expose) active light or radiation through a mask.

  At this time, in the present embodiment, for example, a hole pattern mask (not shown) having a plurality of hole portions arranged at equal intervals in the row direction and the column direction can be used as the light shielding portion.

  However, in the present invention, the mask used in the step (i-2) is not limited to this, and can be appropriately selected according to the desired shape of the first negative pattern, for example, a line portion as a light shielding portion, It is also possible to use a mask having a line-and-space pattern having a space portion as a light transmission portion and having a ratio of the width of the line portion to the width of the space portion of 1: 1.

  In addition, an immersion exposure method can be applied in the exposure in the step (i-2).

  The immersion exposure method is a technique for increasing the resolving power and performing exposure by filling a high refractive index liquid (hereinafter also referred to as “immersion liquid”) between a projection lens and a sample. In addition, immersion exposure can be combined with super-resolution techniques such as phase shift method and modified illumination method.

  When performing immersion exposure, (1) after the first film is formed on the substrate, before the exposure step and / or (2) the first film is exposed via the immersion liquid. After the step, before the step of heating the first film, a step of washing the surface of the first film with an aqueous chemical solution may be performed.

  The immersion liquid is preferably a liquid that is transparent to the exposure wavelength and has a refractive index temperature coefficient as small as possible so as to minimize distortion of the optical image projected onto the first film. It is preferable to use water from the viewpoint of easy availability and ease of handling.

  When water is used, an additive (liquid) that reduces the surface tension of water and increases the surface activity may be added in a small proportion. This additive is preferably one that does not dissolve the resist layer on the wafer and can ignore the influence on the optical coating on the lower surface of the lens element.

  As such an additive, for example, an aliphatic alcohol having a refractive index substantially equal to that of water is preferable, and specific examples include methyl alcohol, ethyl alcohol, isopropyl alcohol and the like. By adding an alcohol having a refractive index substantially equal to that of water, even if the alcohol component in water evaporates and the content concentration changes, an advantage that the change in the refractive index of the entire liquid can be made extremely small can be obtained.

  On the other hand, when an opaque substance or impurities whose refractive index is significantly different from that of water are mixed with respect to 193 nm light, the optical image projected on the resist is distorted. Therefore, distilled water is preferable as the water to be used. Further, pure water filtered through an ion exchange filter or the like may be used.

Moreover, it is possible to improve lithography performance by increasing the refractive index of the immersion liquid. From such a viewpoint, an additive that increases the refractive index may be added to water, or heavy water (D ₂ O) may be used instead of water.

  When the first film formed using the actinic ray-sensitive or radiation-sensitive resin composition (1) is exposed through an immersion medium, the hydrophobic resin (D) described later is further provided as necessary. Can be added. By adding the hydrophobic resin (D), the receding contact angle of the surface is improved. The receding contact angle of the first film is preferably 60 ° to 90 °, more preferably 70 ° or more.

  In the immersion exposure process, the immersion head needs to move on the wafer following the movement of the exposure head scanning the wafer at high speed to form the exposure pattern, so that the dynamic state is reached. In this case, the contact angle of the immersion liquid with respect to the resist film (first film) becomes important, and the resist is required to follow the high-speed scanning of the exposure head without remaining droplets.

  In order to prevent the film from coming into direct contact with the immersion liquid between the first film formed using the actinic ray-sensitive or radiation-sensitive resin composition (1) of the present invention and the immersion liquid, An immersion liquid hardly soluble film (hereinafter also referred to as “top coat”) may be provided. Functions necessary for the top coat include suitability for application to the resist upper layer, transparency to radiation, particularly radiation having a wavelength of 193 nm, and poor immersion liquid solubility. It is preferable that the top coat is not mixed with the resist and can be uniformly applied to the upper layer of the resist.

  From the viewpoint of transparency at 193 nm, the topcoat is preferably a polymer that does not contain aromatics.

  Specific examples include hydrocarbon polymers, acrylic ester polymers, polymethacrylic acid, polyacrylic acid, polyvinyl ether, silicon-containing polymers, and fluorine-containing polymers. The above-mentioned hydrophobic resin (D) is also suitable as a top coat. When impurities are eluted from the top coat into the immersion liquid, the optical lens is contaminated. Therefore, it is preferable that the residual monomer component of the polymer contained in the top coat is small.

  When peeling the top coat, a developer may be used, or a separate release agent may be used. As the release agent, a solvent having a small penetration into the first film is preferable. It is preferable that the peeling process can be carried out with an alkali developer in that the peeling process can be performed simultaneously with the development process of the first film. The top coat is preferably acidic from the viewpoint of peeling with an alkali developer, but may be neutral or alkaline from the viewpoint of non-intermixability with the first film.

  There is preferably no or small difference in refractive index between the top coat and the immersion liquid. In this case, the resolution can be improved. When the exposure light source is an ArF excimer laser (wavelength: 193 nm), it is preferable to use water as the immersion liquid. Therefore, the top coat for ArF immersion exposure is close to the refractive index of water (1.44). preferable. Moreover, it is preferable that a topcoat is a thin film from a viewpoint of transparency and a refractive index.

  The top coat is preferably not mixed with the first film and further not mixed with the immersion liquid. From this viewpoint, when the immersion liquid is water, the solvent used for the topcoat is preferably a water-insoluble medium that is hardly soluble in the solvent used for the resin composition in the present invention. . Further, when the immersion liquid is an organic solvent, the topcoat may be water-soluble or water-insoluble.

-Step (i-3): Development of first film-
In the step (i-3), the exposed first film is developed using a first developer, whereby a plurality of hole portions (the first holes shown in FIGS. 2A and 3A) are formed. A first pattern 40D ′ having one recess 11D) is obtained.

  The first developer used in the step (i-3) may be an organic developer containing an organic solvent or an alkali developer. As described above, it is preferable to use an organic developer in the step (i-3) from the viewpoint of pattern miniaturization.

  The developer used in the step of forming a negative pattern by developing with an organic developer includes polar solvents such as ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents, and carbonization. A hydrogen-based solvent can be used.

  Examples of the ketone solvent include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 2-heptanone (methyl amyl ketone), 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, Examples include cyclohexanone, methylcyclohexanone, phenylacetone, methylethylketone, methylisobutylketone, acetylacetone, acetonylacetone, ionone, diacetylalcohol, acetylcarbinol, acetophenone, methylnaphthylketone, isophorone, and propylene carbonate.

  Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, pentyl acetate, isopentyl acetate, isoamyl acetate, cyclohexyl acetate, isobutyl isobutyrate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol Monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, Examples thereof include butyl lactate, propyl lactate, and butyl butanoate.

  Examples of the alcohol solvent include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, n-hexyl alcohol, n-heptyl alcohol, alcohols such as n-octyl alcohol and n-decanol, glycol solvents such as ethylene glycol, diethylene glycol and triethylene glycol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monoethyl ether, Diethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methoxymethyl butano It can be mentioned glycol ether solvents such as Le.

  Examples of the ether solvent include dioxane, tetrahydrofuran, phenetole, dibutyl ether and the like in addition to the glycol ether solvent.

  Examples of the amide solvent include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, hexamethylphosphoric triamide, 1,3-dimethyl-2-imidazolidinone and the like. Can be used.

  Examples of the hydrocarbon solvent include aromatic hydrocarbon solvents such as toluene and xylene, and aliphatic hydrocarbon solvents such as pentane, hexane, octane, decane, and undecane.

  A plurality of the above solvents may be mixed, or may be used by mixing with a solvent other than those described above or water. However, in order to fully exhibit the effects of the present invention, the water content of the developer as a whole is preferably less than 10% by mass, and more preferably substantially free of moisture.

  That is, the amount of the organic solvent used in the organic developer is preferably 90% by mass or more and 100% by mass or less, and more preferably 95% by mass or more and 100% by mass or less, with respect to the total amount of the developer.

  In particular, the organic developer is preferably a developer containing at least one organic solvent selected from the group consisting of ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents. .

  The vapor pressure of the organic developer is preferably 5 kPa or less, more preferably 3 kPa or less, and particularly preferably 2 kPa or less at 20 ° C. By setting the vapor pressure of the organic developer to 5 kPa or less, the evaporation of the developer on the substrate or in the developing cup is suppressed, and the temperature uniformity in the wafer surface is improved. As a result, the dimensions in the wafer surface are uniform. Sexuality improves.

  Specific examples having a vapor pressure of 5 kPa or less include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, 2-heptanone (methyl amyl ketone), 4-heptanone, 2-hexanone, diisobutyl ketone, Ketone solvents such as cyclohexanone, methylcyclohexanone, phenylacetone, methyl isobutyl ketone, butyl acetate, pentyl acetate, isopentyl acetate, amyl acetate, cyclohexyl acetate, isobutyl isobutyrate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol Monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl Ester solvents such as -3-methoxybutyl acetate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, Alcohol solvents such as isobutyl alcohol, n-hexyl alcohol, n-heptyl alcohol, n-octyl alcohol, n-decanol, glycol solvents such as ethylene glycol, diethylene glycol, triethylene glycol, ethylene glycol monomethyl ether, propylene glycol monomethyl Ether, ethylene glycol monoethyl ether, propylene glycol monoethyl ether, diethylene glycol monomethyl ether, triethylene Glycol ether solvents such as recall monoethyl ether and methoxymethylbutanol, ether solvents such as tetrahydrofuran, phenetol and dibutyl ether, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide amide And aromatic hydrocarbon solvents such as toluene and xylene, and aliphatic hydrocarbon solvents such as octane and decane.

  Specific examples having a vapor pressure of 2 kPa or less, which is a particularly preferable range, include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, 4-heptanone, 2-hexanone, diisobutyl ketone, cyclohexanone, and methylcyclohexanone. , Ketone solvents such as phenylacetone, butyl acetate, amyl acetate, cyclohexyl acetate, isobutyl isobutyrate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3- Ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, ethyl lactate, butyl lactate, propyl lactate, etc. Ester solvents, alcohol solvents such as n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, n-hexyl alcohol, n-heptyl alcohol, n-octyl alcohol, n-decanol, ethylene glycol, diethylene glycol , Glycol solvents such as triethylene glycol, and glycols such as ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monoethyl ether, diethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methoxymethyl butanol Ether solvents, ether solvents such as phenetol and dibutyl ether, N-methyl- - pyrrolidone, N, N- dimethylacetamide, N, N-dimethylformamide amide solvents, aromatic hydrocarbon solvents such as xylene, octane, aliphatic hydrocarbon solvents decane.

  An appropriate amount of a surfactant can be added to the organic developer as required.

  The surfactant is not particularly limited, and for example, ionic or nonionic fluorine-based and / or silicon-based surfactants can be used. Examples of these fluorine and / or silicon surfactants include, for example, JP-A No. 62-36663, JP-A No. 61-226746, JP-A No. 61-226745, JP-A No. 62-170950, JP 63-34540 A, JP 7-230165 A, JP 8-62834 A, JP 9-54432 A, JP 9-5988 A, US Pat. No. 5,405,720, etc. The surfactants described in US Pat. Nos. 5,360,692, 5,298,881, 5,296,330, 5,346,098, 5,576,143, 5,294,511, and 5,824,451 can be mentioned. Preferably, it is a nonionic surfactant. Although it does not specifically limit as a nonionic surfactant, It is still more preferable to use a fluorochemical surfactant or a silicon-type surfactant.

  The amount of the surfactant used is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass with respect to the total amount of the developer.

  Further, an embodiment in which a nitrogen-containing compound (amine or the like) is added to an organic developer as in the invention according to the claim of Japanese Patent No. 5056974 can be preferably used.

  Examples of the alkaline developer include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, primary amines such as ethylamine and n-propylamine, diethylamine, Secondary amines such as di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, fourth amines such as tetramethylammonium hydroxide and tetraethylammonium hydroxide Alkaline aqueous solutions such as cyclic amines such as quaternary ammonium salts, pyrrole, and pihelidine can be used.

Furthermore, an appropriate amount of alcohol or surfactant may be added to the alkaline aqueous solution. Examples of the surfactant include those described above. The alkali concentration of the alkali developer is usually from 0.1 to 20% by mass.
The pH of the alkali developer is usually from 10.0 to 15.0.
In particular, an aqueous solution of 2.38% by mass of tetramethylammonium hydroxide is desirable.

  Step (i-3) may include a development step a plurality of times.

  As a developing method, for example, a method in which a substrate is immersed in a tank filled with a developer for a certain time (dip method), a method in which a developer is raised on the surface of the substrate by surface tension and is left stationary for a certain time (paddle) Method), a method of spraying the developer on the substrate surface (spray method), a method of continuously discharging the developer while scanning the developer discharge nozzle on the substrate rotating at a constant speed (dynamic dispensing method) Etc. can be applied.

When the various development methods described above include a step of discharging the developer from the developing nozzle of the developing device toward the resist film, the discharge pressure of the discharged developer (the flow rate per unit area of the discharged developer) is Preferably it is 2 mL / sec / mm ² or less, More preferably, it is 1.5 mL / sec / mm ² or less, More preferably, it is 1 mL / sec / mm ² or less. There is no particular lower limit on the flow rate, but 0.2 mL / sec / mm ² or more is preferable in consideration of throughput.

  By setting the discharge pressure of the discharged developer to be in the above range, pattern defects derived from the resist residue after development can be remarkably reduced. This is described in detail in Japanese Patent Application Laid-Open No. 2010-232550.

The developer discharge pressure (mL / sec / mm ² ) is a value at the developing nozzle outlet in the developing device.

  Examples of the method for adjusting the discharge pressure of the developer include a method of adjusting the discharge pressure with a pump or the like, and a method of changing the pressure by adjusting the pressure by supply from a pressurized tank.

  In addition, after the step of developing using the first developer, a step of stopping the development may be performed while substituting with another solvent.

-Rinse process-
The step (i) preferably includes a step of washing with a rinsing liquid (rinsing step) after the developing step (i-3).

  When the first developer used in the step (i-3) is an organic developer, the rinsing solution that can be used in the rinsing step after the step (i-3) should not dissolve the resist pattern. There is no restriction | limiting in particular, The solution containing a general organic solvent can be used. As the rinse liquid, a rinse liquid containing at least one organic solvent selected from the group consisting of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents is used. It is preferable.

  Specific examples of the hydrocarbon solvent, the ketone solvent, the ester solvent, the alcohol solvent, the amide solvent, and the ether solvent are the same as those described in the developer containing an organic solvent.

  More preferably, after the step of developing using a developer containing an organic solvent, at least one selected from the group consisting of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents. The step of washing with a rinsing liquid containing an organic solvent is performed, more preferably the step of washing with a rinsing liquid containing a hydrocarbon solvent, an alcohol solvent or an ester solvent, and particularly preferably. The step of washing with a rinsing liquid containing a hydrocarbon solvent and a monohydric alcohol is performed, and the step of washing with a rinsing liquid containing a monohydric alcohol having 5 or more carbon atoms is most preferably performed.

  Here, examples of the monohydric alcohol used in the rinsing step include linear, branched, and cyclic monohydric alcohols, and specifically, 1-butanol, 2-butanol, and 3-methyl-1-butanol. Tert-butyl alcohol, 1-pentanol, 2-pentanol, 1-hexanol, 4-methyl-2-pentanol, 1-heptanol, 1-octanol, 2-hexanol, cyclopentanol, 2-heptanol, 2 -Octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol and the like can be used, and particularly preferable monohydric alcohols having 5 or more carbon atoms include 1-hexanol, 2-hexanol, 4-methyl- Use 2-pentanol, 1-pentanol, 3-methyl-1-butanol, etc. It can be.

  Here, the hydrocarbon solvent used in the rinsing step is preferably an aliphatic hydrocarbon solvent such as pentane, hexane, octane, decane, or undecane, and more preferably an aliphatic hydrocarbon solvent having 10 or more carbon atoms such as undecane. Is more preferable.

  A plurality of the above components may be mixed, or may be used by mixing with an organic solvent other than the above.

  The water content in the rinse liquid is preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 3% by mass or less. By setting the water content to 10% by mass or less, good development characteristics can be obtained.

  The vapor pressure of the rinsing solution used after the step of developing with a developer containing an organic solvent is preferably 0.05 kPa or more and 5 kPa or less, more preferably 0.1 kPa or more and 5 kPa or less at 20 ° C. 12 kPa or more and 3 kPa or less are the most preferable. By setting the vapor pressure of the rinse liquid to 0.05 kPa or more and 5 kPa or less, the temperature uniformity in the wafer surface is improved, and further, the swelling due to the penetration of the rinse solution is suppressed, and the dimensional uniformity in the wafer surface. Improves.

  When the first developer is an alkali developer, pure water is used as a rinse solution used in the rinse step after step (i-3), and an appropriate amount of a surfactant is added. You can also.

  The cleaning method in the rinsing step is not particularly limited. For example, a method of continuously discharging a rinsing liquid onto a substrate rotating at a constant speed (rotary coating method), a substrate in a bath filled with the rinsing liquid Can be applied for a certain period of time (dip method), a method of spraying a rinsing liquid on the substrate surface (spray method), etc. Among them, a cleaning process is performed by a spin coating method, and the substrate is washed at 2000 rpm or more after cleaning. It is preferable to rotate at a rotational speed of 4000 rpm to remove the rinse liquid from the substrate. It is also preferable to include a heating step (Post Bake) after the rinsing step. The developing solution and the rinsing solution remaining between the patterns and inside the patterns are removed by baking. The heating step after the rinsing step is usually 40 to 160 ° C., preferably 70 to 95 ° C., and usually 10 seconds to 3 minutes, preferably 30 seconds to 90 seconds.

In addition, after the developing process or the rinsing process, a process of removing the developing solution or the rinsing liquid adhering to the pattern with a supercritical fluid can be performed.
[<Heating step (iii) between step (i) and step (ii)]
The step (a1) for forming the mask layer may further include a heating step (iii) between the step (i) and the step (ii) described in detail later (FIG. 2B and FIG. 2). FIG. 3 (b)). A first pattern 40D shown in FIGS. 2B and 3B represents a state after the first pattern 40 shown in FIGS. 2A and 3A is heated.

  As a result, the solvent resistance of the first negative pattern 40D ′ formed in the step (i-3) can be further improved, and in the subsequent step (ii), an active sensitivity is formed on the first negative pattern 40D. Even if a light-sensitive or radiation-sensitive resin composition (2) is applied, a first negative pattern that is not easily damaged can be obtained.

The temperature in this heating step (iii) is preferably 150 ° C. or higher, and more preferably 170 ° C. or higher. The said temperature is normally made into 240 degrees C or less. Moreover, the heating time in this heating process is performed in about 30 to 120 seconds. It is preferable that the heating step (iii) is performed in such a temperature range and time, because it is considered that the decomposition residue of the organic substance volatilizes and becomes insoluble in the solvent.
[Step (ii): Formation of second pattern]
In this embodiment described based on FIG.2 and FIG.3, by performing the said process (ii-1), (ii-2), and (ii-3) in this order, a hole part (1st recessed part). 11D), a line and space pattern (second pattern 50D) including a space portion (second recess 12D) is formed on the hole pattern (first pattern 40D) (FIG. 2D). ), FIG. 3 (d)). By the step (a1) including the step (i) and the step (ii), a line and space pattern (second pattern 50D) is laminated on the hole pattern (first pattern 40D), and the hole portion A mask layer having a mask pattern having a multi-stage concave portion 10D composed of (first concave portion 11D) and a space portion (second concave portion 12D) is formed.

  Hereinafter, the steps (ii-1), (ii-2) and (ii-3) will be described in detail.

-Step (ii-1): Formation of second film-
In step (ii-1), as shown in FIGS. 2 (c) and 3 (c), an actinic ray-sensitive or radiation-sensitive resin composition (2) is formed on the first negative pattern 40D. The second film 50D ′ is formed by using this. Note that in the case where heat treatment is not performed between the step (i) and the step (ii), the second film is formed on the first pattern 40D ′ described in FIGS. 2 (a) and 3 (a). It is formed.

  The actinic ray-sensitive or radiation-sensitive resin composition (2) will be described in detail later.

  In the step (ii-1), the second film 50D ′ may be formed at least on the film part of the first negative pattern 40D, and the first recess 11D includes the first film 11D. The second film 50D ′ may or may not be formed.

  However, as will be described later, the method of forming the second film using the actinic ray-sensitive or radiation-sensitive resin composition (2) is typically an actinic ray-sensitive or radiation-sensitive resin composition. It can be carried out by applying (2). For this reason, not forming the second film 50D ′ in the first recess 11D in the step (ii-1) may make the operation complicated.

  Therefore, in the step (ii-1), it is preferable to form the second film 50D ′ also in the first recess 11D as shown in FIG.

  Further, the second film 50D ′ is formed only on the surface of a part of the film portion of the first negative pattern 40D, even if it is not on the entire surface of the film portion of the first negative pattern 40D. It may be a thing.

  In the step (ii-1), the method for forming the second film using the actinic ray-sensitive or radiation-sensitive resin composition (2) is the same as the step (i-1) in which the actinic ray-sensitive or radiation-sensitive material is formed. This is the same as the method of forming the first film using the conductive resin composition (1).

  The preferred range of the thickness of the second film is the same as that described as the preferred range of the thickness of the first film, but the thickness of the second film is the same as the thickness of the first film. May be different.

  The film thickness of the second film here means the film thickness of the second film formed on the first negative pattern, and the second film formed in the first recess 11D. The film is not considered.

-Pre-heating step and post-exposure heating step-
The step (ii) preferably includes a preheating step (PB; Prebake) between the step (ii-1) and the step (ii-2).

  The step (ii) preferably includes a post-exposure heating step (PEB; Post Exposure Bake) between the step (ii-2) and the step (ii-3).

  The heating temperature is preferably 70 to 130 ° C., more preferably 80 to 120 ° C. for both PB and PEB.

  The heating time is preferably 30 to 300 seconds, more preferably 30 to 180 seconds, and still more preferably 30 to 90 seconds.

  Heating can be performed by means provided in a normal exposure / developing machine, and may be performed using a hot plate or the like.

  The reaction of the exposed part is promoted by baking, and the sensitivity and pattern profile are improved.

  At least one of the preheating step and the post-exposure heating step may include a plurality of heating steps.

-Step (ii-2): Exposure of second film-
Next, the exposed second film 60 is obtained by exposing the second film 50D ′ (step (ii-2)).

  As in step (i-2), for example, when the light source is a KrF excimer laser, an ArF excimer laser, or EUV, actinic rays or radiation is irradiated (that is, exposed) through a mask (not shown). It is preferable.

  The mask pattern in the mask used in step (ii-2) is not particularly limited, but in the present embodiment, a mask different from the mask used in step (i-2) is used.

  Specifically, the mask has a line-and-space pattern having a line part as a light-shielding part and a space part as a light transmission part, and the ratio of the width of the line part to the width of the space part is 1: 1. A mask (not shown) is used in a state where the light shielding portion of the mask covers each of the hole portions of the first negative pattern 40D.

  However, similarly to the mask used in the step (i-2), the mask in the step (ii-2) is not limited to the above-described mask, and depends on the shape of the desired second negative pattern, etc. It can be selected as appropriate.

  As the exposure method in step (ii-2), the same method as described in the exposure in step (i-2) can be employed. From the viewpoint of improving throughput, the exposure light source in step (ii-2) is preferably the same as the exposure light source in step (i-2).

-Step (ii-3): Development of second film-
Next, the exposed second film is developed using a second developer to form a second negative pattern 50D as shown in FIG. 2D and FIG. ii-3)).

  The second developer used in the step (ii-3) may be an organic developer containing an organic solvent, as in the case of the first developer used in the step (i-3). As described above, from the viewpoint of pattern miniaturization, it is preferable to form a negative pattern using an organic developer in step (ii-3).

  The organic developer and the alkali developer as the second developer can be the same as those described in the first developer in the step (i-3).

  In the present embodiment, as shown in FIGS. 2D and 3D, the hole portion (first concave portion 11D) is formed on the hole pattern (first negative pattern 40D) having a plurality of hole portions. A line-and-space pattern (second negative pattern 50D) is formed so that the space (second recess 12D) is positioned on the top and the hole is exposed.

  Thus, according to this embodiment of the step (a), the mask pattern is composed of the first negative pattern 40D that is a hole pattern and the second negative pattern 50D that is a line and space pattern, A multilayer body 110D is obtained in which a multi-stage structure mask pattern having a multi-stage structure concave portion 10D whose width decreases stepwise in the depth direction is formed on the multilayer substrate 110D.

  Needless to say, the multi-stage structure mask pattern formed by the step (a) is not limited to this.

  Step (ii-3) may include a development step a plurality of times.

-Rinse process-
The step (ii) preferably includes a step of rinsing with a rinsing solution (rinsing step) after the developing step (ii-3), that is, after the step of developing with the second developer. The rinsing liquid in this case is not particularly limited unless the resist pattern is dissolved when the second developer used in step (ii-3) is an organic developer. A solution containing can be used. As such a rinse liquid, what was demonstrated as the rinse liquid containing an organic solvent in description of the rinse process which process (i) may contain can be used similarly.

  In addition, when the second developer used in step (ii-3) is an alkaline developer, it is preferable to use pure water as the rinsing solution, and use by adding an appropriate amount of a surfactant. You can also

  Examples of the cleaning treatment in these rinsing steps can be the same as those described above.

<Heating Step (iii ′) Between Step (ii-3) and Step (b)>
The method for producing a stepped substrate of the present invention may include a heating step (iii ′) after the step (ii-3), that is, after the step of developing using the second developer. This heating step (iii ′) is preferably performed after the step (ii-3) and before the etching treatment step (b) described later.

As the various conditions (heating temperature, heating time, etc.) in the heating step (iii ′), those described in the heating step (iii) described above can be adopted.
<Modification>
The first negative pattern in the present embodiment described above may be formed by performing patterning of the first film twice or more.

  In other words, the step (i) of forming the first negative pattern includes the step (i-1), the step (i-2), and the step (i-3) in this order. May be included a plurality of times (hereinafter, this embodiment is also referred to as a modified example).

  In this case, a plurality of pattern forming steps may further include a heating step between two successive pattern forming steps.

  Hereinafter, the modified example will be specifically described.

  First, by carrying out step (i-1), step (i-2) and step (i-3) in this order by the same method as above, a first negative pattern is formed on the substrate. For example, a line and space pattern (not shown) having a line width and a space width of 1: 3 is formed.

  Next, a heating step (so-called freezing step) may be performed, whereby the solvent resistance of the line and space pattern can be further improved, and subsequently, in the concave portion (space) of the line and space pattern of the substrate, Even if another actinic ray-sensitive or radiation-sensitive resin composition (1) is applied, a line and space pattern that is not easily damaged can be formed. In addition, what was demonstrated in the heating process (iii) mentioned above is employable as various conditions of a heating process.

  Next, the first negative is performed by performing the step (i-1), the step (i-2) and the step (i-3) in this order on the concave portion (space) of the line and space pattern of the substrate. As the mold pattern, for example, a line and space pattern having a line width and a space width of 1: 3 is formed.

  As a result, the line and space pattern formed in the previous pattern formation process and the line and space pattern formed in the subsequent pattern formation process are formed on the substrate. A 1: 1 first negative pattern is formed.

  Next, a heating step (a so-called freezing step) may be performed.

And a mask layer can be formed by performing the process of a process (ii) with respect to the 1st negative pattern obtained in this way.
<Actinic ray-sensitive or radiation-sensitive resin composition (1)>
Next, the actinic ray-sensitive or radiation-sensitive resin composition (1) used in step (i) of the mask layer forming step (a1) by photolithography (also simply referred to as “resin composition (1)”). ).

  The actinic ray-sensitive or radiation-sensitive resin composition (1) is typically a resist composition, and is a negative resist composition (that is, a resist composition for developing an organic solvent). The actinic ray-sensitive or radiation-sensitive resin composition (1) is typically a chemically amplified resist composition.

[1] Resin whose polarity is increased by the action of an acid and its solubility in a developer containing an organic solvent is reduced. The acid-decomposable resin composition (1) is a developer containing an organic solvent whose polarity is increased by the action of an acid. It is preferable to contain a resin whose solubility in the liquid decreases (hereinafter also referred to as “acid-decomposable resin” or “resin (A)”).

  As the acid-decomposable resin, for example, a group that decomposes into the main chain or side chain of the resin or both the main chain and the side chain by the action of an acid to generate a polar group (hereinafter referred to as “acid-decomposable group” (Also referred to as).

  The acid-decomposable group preferably has a structure protected by a group capable of decomposing and leaving a polar group by the action of an acid. Preferable polar groups include a carboxyl group, a phenolic hydroxyl group, an alcoholic hydroxyl group (alcoholic means that it does not show acidity like a so-called phenolic hydroxyl group), and a sulfonic acid group.

  A preferable group as the acid-decomposable group is a group in which the hydrogen atom of these groups is substituted with a group capable of leaving with an acid.

As the acid eliminable group, there can be, for _{example, -C (R 36) (R} 37) (R 38), - C (R 36) (R 37) (OR 39), - C (R 01) (R 02 ) (OR ₃₉ ) and the like.

In the formula, R _{36 to} R ₃₉ each independently represents an alkyl group, a cycloalkyl group (monocyclic or polycyclic), an aryl group, an aralkyl group, or an alkenyl group. R ₃₆ and R ₃₇ may be bonded to each other to form a ring.

R ₀₁ and R ₀₂ each independently represents a hydrogen atom, an alkyl group (monocyclic or polycyclic), a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group.

  The acid-decomposable group is preferably a cumyl ester group, an enol ester group, an acetal ester group, a tertiary alkyl ester group or the like. More preferably, it is a tertiary alkyl ester group. Further, when the pattern forming method of the present invention is performed by exposure with KrF light or EUV light, or electron beam irradiation, it is also preferable to use an acid-decomposable group in which a phenolic hydroxyl group is protected with an acid leaving group.

  The resin (A) preferably has a repeating unit having an acid-decomposable group.

  Examples of this repeating unit include the following.

In general formulas (aI) and (aI ′)
Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom.

  T represents a single bond or a divalent linking group.

Rx _{1 to} Rx ₃ each independently represents an alkyl group or a cycloalkyl group. Two of Rx _{1 to} Rx ₃ may combine to form a ring structure. The ring structure may contain a hetero atom such as an oxygen atom in the ring.

  Examples of the divalent linking group for T include an alkylene group, —COO—Rt— group, —O—Rt— group, and a phenylene group. In the formula, Rt represents an alkylene group or a cycloalkylene group.

T in the general formula (aI) is preferably a single bond or a —COO—Rt— group, more preferably a —COO—Rt— group, from the viewpoint of insolubilization of the resist with respect to the organic solvent developer. Rt is preferably an alkylene group having 1 to 5 carbon atoms, more preferably a —CH ₂ — group, — (CH ₂ ) ₂ — group, or — (CH ₂ ) ₃ — group.

  T in the general formula (aI ′) is preferably a single bond.

The alkyl group of _Xa1 may have a substituent, and examples of the substituent include a hydroxyl group and a halogen atom (preferably a fluorine atom).

The alkyl group for _Xa1 preferably has 1 to 4 carbon atoms, and more preferably a methyl group.

X _a1 is preferably a hydrogen atom or a methyl group.

The alkyl group for Rx ₁ , Rx ₂ and Rx ₃ may be linear or branched.

Examples of the cycloalkyl group of Rx ₁ , Rx ₂ and Rx ₃ include polycyclic rings such as a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group and an adamantyl group. Are preferred.

The ring structure formed by combining two of Rx ₁ , Rx ₂ and Rx ₃ includes a monocyclic cycloalkane ring such as a cyclopentyl ring and a cyclohexyl ring, a norbornane ring, a tetracyclodecane ring, a tetracyclododecane ring, an adamantane ring A polycyclic cycloalkyl group such as is preferable. A monocyclic cycloalkane ring having 5 or 6 carbon atoms is particularly preferable.

Rx ₁ , Rx ₂ and Rx ₃ are preferably each independently an alkyl group, more preferably a linear or branched alkyl group having 1 to 4 carbon atoms.

  Each of the above groups may have a substituent, and examples of the substituent include an alkyl group (1 to 4 carbon atoms), a cycloalkyl group (3 to 8 carbon atoms), a halogen atom, an alkoxy group (carbon). Number 1-4), a carboxyl group, an alkoxycarbonyl group (carbon number 2-6) etc. are mentioned, and carbon number 8 or less is preferable. Among these, from the viewpoint of further improving the dissolution contrast with respect to a developer containing an organic solvent before and after acid decomposition, a substituent having no hetero atom such as an oxygen atom, a nitrogen atom, or a sulfur atom is more preferable ( For example, it is more preferable that it is not an alkyl group substituted with a hydroxyl group, etc.), a group consisting of only a hydrogen atom and a carbon atom is more preferable, and a linear or branched alkyl group or a cycloalkyl group is particularly preferable. preferable.

  When the composition of the present invention is irradiated with KrF excimer laser light, electron beam, X-ray, or high-energy light (for example, EUV) having a wavelength of 50 nm or less, the resin (A) has a hydroxystyrene repeating unit. It is preferable. More preferably, the resin (A) is a copolymer of hydroxystyrene and hydroxystyrene protected with a group capable of leaving by the action of an acid, or hydroxystyrene and a (meth) acrylic acid tertiary alkyl ester. It is a copolymer.

  Specific examples of such a resin include a resin having a repeating unit represented by the following general formula (A).

In the formula, R ₀₁ , R ₀₂ and R ₀₃ each independently represent, for example, a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group. Ar ₁ represents an aromatic ring group, for example. Note that R ₀₃ and Ar ₁ are alkylene groups, and they may be bonded to each other to form a 5-membered or 6-membered ring together with the —C—C— chain.

  n Y's each independently represent a hydrogen atom or a group capable of leaving by the action of an acid. However, at least one of Y represents a group capable of leaving by the action of an acid.

  n represents an integer of 1 to 4, preferably 1 to 2, and more preferably 1.

The alkyl group as R _{01 to} R ₀₃ is, for example, an alkyl group having 20 or less carbon atoms, and preferably a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, or a hexyl group. , 2-ethylhexyl group, octyl group or dodecyl group. More preferably, these alkyl groups are alkyl groups having 8 or less carbon atoms. In addition, these alkyl groups may have a substituent.

The alkyl group contained in the alkoxycarbonyl group is preferably the same as the alkyl group in R _{01 to} R ₀₃ described above.

  The cycloalkyl group may be a monocyclic cycloalkyl group or a polycyclic cycloalkyl group. Preferably, a C3-C8 monocyclic cycloalkyl group, such as a cyclopropyl group, a cyclopentyl group, and a cyclohexyl group, is mentioned. In addition, these cycloalkyl groups may have a substituent.

  Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is more preferable.

When R ₀₃ represents an alkylene group, the alkylene group is preferably an alkylene group having 1 to 8 carbon atoms such as a methylene group, an ethylene group, a propylene group, a butylene group, a hexylene group, or an octylene group.

The aromatic ring group as Ar ₁ preferably has 6 to 14 carbon atoms, and examples thereof include a benzene ring, a toluene ring, and a naphthalene ring. In addition, these aromatic ring groups may have a substituent.

Examples of the group Y leaving by the action of an acid include —C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ), —C (═O) —O—C (R ₃₆ ) (R ₃₇ ) (R ₃₈ ). _{), - C (R 01)} (R 02) (oR 39), - C (R 01) (R 02) -C (= O) -O-C (R 36) (R 37) (R 38) , or A group represented by —CH (R ₃₆ ) (Ar) may be mentioned.

In the formula, R _{36 to} R ₃₉ each independently represents an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group. R ₃₆ and R ₃₇ may be bonded to each other to form a ring structure.

R ₀₁ and R ₀₂ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group.

  Ar represents an aryl group.

The alkyl group as R _{36 to} R ₃₉ , R ₀₁ , or R ₀₂ is preferably an alkyl group having 1 to 8 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, sec- A butyl group, a hexyl group, and an octyl group are mentioned.

The cycloalkyl group as R _{36 to} R ₃₉ , R ₀₁ , or R ₀₂ may be a monocyclic cycloalkyl group or a polycyclic cycloalkyl group. The monocyclic cycloalkyl group is preferably a cycloalkyl group having 3 to 8 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group. As the polycyclic cycloalkyl group, a cycloalkyl group having 6 to 20 carbon atoms is preferable. A tetracyclododecyl group and an androstanyl group are mentioned. A part of carbon atoms in the cycloalkyl group may be substituted with a hetero atom such as an oxygen atom.

The aryl group as R _{36 to} R ₃₉ , R ₀₁ , R ₀₂ , or Ar is preferably an aryl group having 6 to 10 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group.

The aralkyl group as R _{36 to} R ₃₉ , R ₀₁ , or R ₀₂ is preferably an aralkyl group having 7 to 12 carbon atoms, and for example, a benzyl group, a phenethyl group, and a naphthylmethyl group are preferable.

The alkenyl group as R _{36 to} R ₃₉ , R ₀₁ , or R ₀₂ is preferably an alkenyl group having 2 to 8 carbon atoms, and examples thereof include a vinyl group, an allyl group, a butenyl group, and a cyclohexenyl group. .

The ring that R ₃₆ and R ₃₇ may be bonded to each other may be monocyclic or polycyclic. The monocyclic type is preferably a cycloalkane structure having 3 to 8 carbon atoms, and examples thereof include a cyclopropane structure, a cyclobutane structure, a cyclopentane structure, a cyclohexane structure, a cycloheptane structure, and a cyclooctane structure. As the polycyclic type, a cycloalkane structure having 6 to 20 carbon atoms is preferable, and examples thereof include an adamantane structure, a norbornane structure, a dicyclopentane structure, a tricyclodecane structure, and a tetracyclododecane structure. Note that some of the carbon atoms in the ring structure may be substituted with a heteroatom such as an oxygen atom.

Each of the above groups may have a substituent. Examples of this substituent include alkyl groups, cycloalkyl groups, aryl groups, amino groups, amide groups, ureido groups, urethane groups, hydroxyl groups, carboxyl groups, halogen atoms, alkoxy groups, thioether groups, acyl groups, and acyloxy groups. , Alkoxycarbonyl group, cyano group and nitro group. These substituents preferably have 8 or less carbon atoms.
One type of repeating unit having an acid-decomposable group may be used, or two or more types may be used in combination. When two types are used in combination, the combination is not particularly limited. For example, (1) a repeating unit that decomposes by the action of an acid to generate a carboxyl group and a repeating unit that decomposes by the action of an acid to generate an alcoholic hydroxyl group (2) A combination of a repeating unit that decomposes by the action of an acid to generate a carboxyl group and a repeating unit that decomposes by the action of an acid to generate a phenolic hydroxyl group, (3) Decomposed by the action of an acid Thus, a combination of two types of repeating units that generate a carboxyl group (having different structures) can be considered.
The content of the repeating unit having an acid-decomposable group contained in the resin (A) (the total when there are a plurality of repeating units having an acid-decomposable group) is not particularly limited. The lower limit of the unit is preferably 15 mol% or more, more preferably 20 mol% or more, further preferably 25 mol% or more, and particularly preferably 40 mol% or more. . Moreover, as an upper limit, it is preferable that it is 90 mol% or less, It is more preferable that it is 75 mol% or less, It is more preferable that it is 65 mol% or less.

The resin (A) may contain a repeating unit having a lactone structure or a sultone structure.
Two or more types of repeating units having a lactone structure or a sultone structure can be used in combination.

When the resin (A) contains a repeating unit having a lactone structure or a sultone structure, the content of the repeating unit having a lactone structure or a sultone structure is 5 to 60 mol% with respect to all the repeating units in the resin (A). Is more preferable, more preferably 5-55 mol%, still more preferably 10-50 mol%.
The resin (A) may have a repeating unit having a hydroxyl group or a cyano group.
When the resin (A) contains a repeating unit having a hydroxyl group or a cyano group, the content of the repeating unit having a hydroxyl group or a cyano group is preferably from 3 to 25 mol% based on all repeating units in the resin (A). More preferably, it is 5-15 mol%.

  Resin (A) may have a repeating unit having an acid group.

The resin (A) may or may not contain a repeating unit having an acid group, but when it is contained, the content of the repeating unit having an acid group is relative to all the repeating units in the resin (A). It is preferably 25 mol% or less, and more preferably 20 mol% or less. When resin (A) contains the repeating unit which has an acid group, content of the repeating unit which has an acid group in resin (A) is 1 mol% or more normally.
The resin (A) further has an alicyclic hydrocarbon structure and / or an aromatic ring structure that does not have a polar group (for example, the acid group, hydroxyl group, cyano group), and has a repeating unit that does not exhibit acid decomposability. be able to.
The content of this repeating unit is preferably from 1 to 50 mol%, more preferably from 5 to 50 mol%, still more preferably from 5 to 30 mol%, based on all repeating units in the resin (A).
The form of the resin (A) in the present invention may be any of random type, block type, comb type, and star type. Resin (A) is compoundable by the radical, cation, or anion polymerization of the unsaturated monomer corresponding to each structure, for example. It is also possible to obtain the desired resin by conducting a polymer reaction after polymerization using an unsaturated monomer corresponding to the precursor of each structure.

  When the resin composition (1) is used for ArF exposure, the resin (A) used for the resin composition (1) has substantially no aromatic ring from the viewpoint of transparency to ArF light (specifically Specifically, the ratio of the repeating unit having an aromatic group in the resin is preferably 5 mol% or less, more preferably 3 mol% or less, ideally 0 mol%, that is, no aromatic group. The resin (A) preferably has a monocyclic or polycyclic alicyclic hydrocarbon structure.

  When resin composition (1) contains resin (D) mentioned below, it is preferred that resin (A) does not contain a fluorine atom and a silicon atom from a compatible viewpoint with resin (D).

  The resin (A) used in the resin composition (1) is preferably one in which all of the repeating units are composed of (meth) acrylate repeating units. In this case, all of the repeating units are methacrylate repeating units, all of the repeating units are acrylate repeating units, or all of the repeating units are methacrylate repeating units and acrylate repeating units. Although it can be used, the acrylate-based repeating unit is preferably 50 mol% or less of the total repeating units.

When the resin composition (1) is irradiated with KrF excimer laser light, electron beam, X-ray, or high-energy light (EUV, etc.) having a wavelength of 50 nm or less, the resin (A) has a repeating unit having an aromatic ring. May be. The repeating unit having an aromatic ring is not particularly limited, and is also exemplified in the above description of each repeating unit, but a styrene unit, a hydroxystyrene unit, a phenyl (meth) acrylate unit, a hydroxyphenyl (meth) acrylate. Examples include units. More specifically, the resin (A) is a resin having a hydroxystyrene-based repeating unit and a hydroxystyrene-based repeating unit protected by an acid-decomposable group, a repeating unit having the aromatic ring, and (meth) Examples thereof include a resin having a repeating unit in which the carboxylic acid moiety of acrylic acid is protected by an acid-decomposable group. In particular, particularly in the case of EUV exposure, since high sensitivity is generally required, the resin (A) preferably contains a repeating unit containing a protective group that easily undergoes acid decomposition. Specific examples of the repeating unit include -C (R ₃₆ ) (R ₃₇ ) (OR ₃₉ ) or -C (R ₀₁ ) (R ₀₂ ) ( A compound represented by OR ₃₉ ) (a structure commonly referred to as an acetal type protecting group) is preferred.

  The resin (A) in the present invention can be synthesized and purified according to a conventional method (for example, radical polymerization). For the synthesis method and purification method, see, for example, the descriptions in paragraphs 0201 to 0202 of JP-A-2008-292975.

  The weight average molecular weight of the resin (A) in the present invention is generally 1000 or more, preferably 7,000 to 200,000, more preferably 7,000 to 50, in terms of polystyrene by GPC method. 7,000, even more preferably 7,000 to 40,000, particularly preferably 7,000 to 30,000. When the weight average molecular weight is 7000 or more, it is possible to prevent the solubility in the organic developer from becoming too high, and it is easy to form a precise pattern.

  The dispersity (molecular weight distribution) is usually 1.0 to 3.0, preferably 1.0 to 2.6, more preferably 1.0 to 2.0, and particularly preferably 1.4 to 2.0. Those in the range are used. The smaller the molecular weight distribution, the better the resolution and the resist shape, the smoother the sidewall of the resist pattern, and the better the roughness.

  In the actinic ray-sensitive or radiation-sensitive resin composition (1) of the present invention, the mixing ratio of the resin (A) in the entire composition is preferably 30 to 99% by mass, more preferably 60 to 60% in the total solid content. 95% by mass.

In the present invention, the resin (A) may be used alone or in combination.
[2] Compound that generates acid upon irradiation with actinic ray or radiation Resin composition (1) is usually a compound that generates acid upon irradiation with actinic ray or radiation (hereinafter referred to as “compound (B)” or “acid generation”. Also referred to as “agent”. The compound (B) that generates an acid upon irradiation with actinic rays or radiation is preferably a compound that generates an organic acid upon irradiation with actinic rays or radiation.

  As the acid generator, photo-initiator of photocation polymerization, photo-initiator of photo-radical polymerization, photo-decoloring agent of dyes, photo-discoloring agent, irradiation of actinic ray or radiation used for micro resist, etc. The known compounds that generate an acid and mixtures thereof can be appropriately selected and used.

Examples thereof include diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, disulfones, and o-nitrobenzyl sulfonates.
The acid generator can be synthesized by a known method. For example, [0200] to [0210] of JP-A No. 2007-161707, JP-A No. 2010-100595, and International Publication No. 2011/093280 [ [0051] to [0058], [0382] to [0385] of International Publication No. 2008/153110, and the like.

  An acid generator can be used individually by 1 type or in combination of 2 or more types.

  The content of the compound that generates an acid upon irradiation with actinic rays or radiation in the composition is preferably 0.1 to 30% by mass, more preferably 0. 0% by mass based on the total solid content of the resin composition (1). It is 5-25 mass%, More preferably, it is 3-20 mass%, Most preferably, it is 3-15 mass%.

  In addition, depending on the actinic ray-sensitive or radiation-sensitive resin composition, there is also an embodiment (B ′) in which a structure corresponding to the acid generator is supported on the resin (A). Specifically, as such an embodiment, a structure described in JP2011-248019A (particularly, a structure described in paragraphs 0164 to 0191, a structure included in the resin described in the example in paragraph 0555). And the repeating unit (R) described in paragraphs 0023 to 0210 of JP2013-80002A, and the contents thereof are incorporated in the present specification. Incidentally, even if the structure corresponding to the acid generator is supported by the resin (A), the actinic ray-sensitive or radiation-sensitive resin composition is additionally added to the resin (A). An unsupported acid generator may be included.

  Examples of the embodiment (B ′) include the following repeating units, but are not limited thereto.

[3] Solvent The resin composition (1) usually contains a solvent.
Examples of the solvent that can be used in preparing the resin composition (1) include alkylene glycol monoalkyl ether carboxylates, alkylene glycol monoalkyl ethers, alkyl lactate esters, alkyl alkoxypropionates, and cyclic lactones (preferably Examples thereof include organic solvents such as carbon number 4 to 10), monoketone compounds (preferably having 4 to 10 carbon atoms) which may have a ring, alkylene carbonate, alkyl alkoxyacetate, and alkyl pyruvate.

  Specific examples of these solvents can include those described in US Patent Application Publication No. 2008/0187860 [0441] to [0455].

In the present invention, a plurality of organic solvents may be mixed and used.
For example, you may use the mixed solvent which mixed the solvent which contains a hydroxyl group in a structure, and the solvent which does not contain a hydroxyl group as an organic solvent. As the solvent containing a hydroxyl group and the solvent not containing a hydroxyl group, the above-mentioned exemplary compounds can be selected as appropriate. As the solvent containing a hydroxyl group, alkylene glycol monoalkyl ether, alkyl lactate and the like are preferable, and propylene glycol monomethyl ether ( PGME, also known as 1-methoxy-2-propanol), ethyl lactate, and methyl 2-hydroxyisobutyrate are more preferred. Further, as the solvent not containing a hydroxyl group, alkylene glycol monoalkyl ether acetate, alkyl alkoxypropionate, monoketone compound which may contain a ring, cyclic lactone, alkyl acetate and the like are preferable, and among these, propylene glycol monomethyl ether Acetate (PGMEA, also known as 1-methoxy-2-acetoxypropane), ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, butyl acetate are particularly preferred, propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2 -Heptanone is most preferred.

  Of course, organic solvents that do not contain a hydroxyl group in the structure can be used together. Examples of this combination include PGMEA and cyclohexanone, PGMEA and cyclopentanone, PGMEA and γ-butyrolactone, PGMEA and 2-heptanone, and the like.

  For example, when using 2 types of solvents, the mixing ratio (mass) is 1/99 to 99/1, preferably 10/90 to 90/10, and more preferably 20/80 to 60/40.

  The solvent preferably contains propylene glycol monomethyl ether acetate, and is preferably a propylene glycol monomethyl ether acetate single solvent or a mixed solvent of two or more containing propylene glycol monomethyl ether acetate.

  When an appropriate amount of a relatively high boiling point solvent such as γ-butyrolactone is used, it can be expected that the performance of the hydrophobic resin (D) described later is more unevenly distributed on the surface and the performance for immersion exposure is improved.

  Furthermore, you may use 3 or more types of solvents. As a result, fine adjustment of resist shape, adjustment of viscosity, and the like may be performed. Examples of the combination include PGMEA · PGME · γ-butyrolactone, PGMEA · PGME · cyclohexanone, PGMEA · PGME · 2-heptanone, PGMEA · cyclohexanone · γ-butyrolactone, PGMEA · γ-butyrolactone · 2-heptanone, and the like.

  As the solvent, it is preferable to use a solvent having a reduced peroxide content, thereby improving the storage stability of the resist composition. The content of the peroxide in the solvent is preferably 2.0 mmol% or less, more preferably 1.0 mmol% or less, still more preferably 0.5 mmol% or less, and the peroxide. It is particularly preferable that substantially no is contained.

[4] Hydrophobic resin (D)
The resin composition (1) may contain a hydrophobic resin (hereinafter also referred to as “hydrophobic resin (D)” or simply “resin (D)”), particularly when applied to immersion exposure. The hydrophobic resin (D) is preferably different from the resin (A).

  As a result, the hydrophobic resin (D) is unevenly distributed in the film surface layer, and when the immersion medium is water, the static / dynamic contact angle of the resist film surface with water is improved, and the immersion liquid followability is improved. be able to.

  The hydrophobic resin (D) may be included for various purposes even when the resin composition (1) is not applied to immersion exposure. For example, when applying the resin composition (1) to EUV exposure, it is also preferable to use the hydrophobic resin (D) in anticipation of outgas suppression and pattern shape adjustment.

  The hydrophobic resin (D) is preferably designed to be unevenly distributed at the interface as described above. However, unlike the surfactant, the hydrophobic resin (D) does not necessarily need to have a hydrophilic group in the molecule. There is no need to contribute to uniform mixing.

The hydrophobic resin (D) is selected from any one of “fluorine atom”, “silicon atom”, and “CH ₃ partial structure contained in the side chain portion of the resin” from the viewpoint of uneven distribution in the film surface layer. It is preferable to have the above, and it is more preferable to have two or more.

  The weight average molecular weight of the hydrophobic resin (D) in terms of standard polystyrene is preferably 1,000 to 100,000, more preferably 1,000 to 50,000, and still more preferably 2,000 to 15,000. is there.

  In addition, the hydrophobic resin (D) may be used alone or in combination.

  The content of the hydrophobic resin (D) in the composition is preferably 0.01 to 10% by mass, more preferably 0.05 to 8% by mass, based on the total solid content in the resin composition (1). 0.1-7 mass% is still more preferable.

  As for the hydrophobic resin (D), as in the resin (A), it is natural that the residual monomer and oligomer components are preferably 0.01 to 5% by mass, and more preferably less impurities such as metals. Is more preferably 0.01 to 3% by mass and 0.05 to 1% by mass. Thereby, the resin composition (1) which does not change over time, such as a foreign substance in liquid and sensitivity, is obtained. The molecular weight distribution (Mw / Mn, also referred to as dispersity) is preferably in the range of 1 to 5, more preferably 1 to 3, and still more preferably from the viewpoints of resolution, resist shape, resist pattern sidewall, roughness, and the like. It is the range of 1-2.

  As the hydrophobic resin (D), various commercially available products can be used, and the hydrophobic resin (D) can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, a monomer polymerization method in which a monomer species and an initiator are dissolved in a solvent and heating is performed, and a solution of the monomer species and the initiator is dropped into the heating solvent over 1 to 10 hours. The dropping polymerization method is added, and the dropping polymerization method is preferable.

  The reaction solvent, the polymerization initiator, the reaction conditions (temperature, concentration, etc.) and the purification method after the reaction are the same as those described for the resin (A), but in the synthesis of the hydrophobic resin (D), The reaction concentration is preferably 30 to 50% by mass. For more details, refer to the description in paragraphs 0320 to 0329 of JP-A-2008-292975.

  Specific examples of the hydrophobic resin (D) are shown below. The following table shows the molar ratio of repeating units in each resin (corresponding to each repeating unit in order from the left), the weight average molecular weight, and the degree of dispersion.

[5] Basic compound The resin composition (1) preferably contains a basic compound.

  (1) In one form, the resin composition (1) has a basic compound or an ammonium salt compound (hereinafter, referred to as “compound (N)”) whose basicity is reduced by irradiation with actinic rays or radiation. It is preferable to contain.

  The compound (N) is preferably a compound (N-1) having a basic functional group or an ammonium group and a group that generates an acidic functional group upon irradiation with actinic rays or radiation. That is, the compound (N) is a basic compound having a basic functional group and a group capable of generating an acidic functional group upon irradiation with actinic light or radiation, or an acidic functional group upon irradiation with an ammonium group and active light or radiation. An ammonium salt compound having a group to be generated is preferable.

  Specific examples of the compound (N) include the following compounds. In addition to the compounds listed below, examples of the compound (N) include compounds (A-1) to (A-44) described in US Patent Application Publication No. 2010/0233629, and US patent applications. The compounds of (A-1) to (A-23) described in JP 2012/0156617 A can also be preferably used in the present invention.

These compounds can be synthesized according to the synthesis examples described in JP-A-2006-330098.

  The molecular weight of the compound (N) is preferably 500 to 1000.

  The resin composition (1) may or may not contain the compound (N), but when it is contained, the content of the compound (N) is based on the solid content of the resin composition (1). 0.1-20 mass% is preferable, More preferably, it is 0.1-10 mass%.

  (2) In another embodiment, the resin composition (1) is a basic compound (N) different from the compound (N) as a basic compound in order to reduce a change in performance over time from exposure to heating. ') May be included.

  Preferred examples of the basic compound (N ′) include compounds having structures represented by the following formulas (A ′) to (E ′).

In general formulas (A ′) and (E ′):
RA ²⁰⁰ , RA ²⁰¹ and RA ²⁰² may be the same or different and are a hydrogen atom, an alkyl group (preferably having a carbon number of 1 to 20), a cycloalkyl group (preferably having a carbon number of 3 to 20) or an aryl group (having a carbon number). 6-20), and RA ²⁰¹ and RA ²⁰² may be bonded to each other to form a ring. RA ²⁰³ , RA ²⁰⁴ , RA ²⁰⁵ and RA ²⁰⁶ may be the same or different and each represents an alkyl group (preferably having 1 to 20 carbon atoms).

  The alkyl group may have a substituent, and examples of the alkyl group having a substituent include an aminoalkyl group having 1 to 20 carbon atoms, a hydroxyalkyl group having 1 to 20 carbon atoms, and a carbon atom having 1 to 20 carbon atoms. A cyanoalkyl group is preferred.

  The alkyl groups in the general formulas (A ′) and (E ′) are more preferably unsubstituted.

  Specific examples of the basic compound (N ′) include guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine, piperidine, and more preferable specific examples include an imidazole structure. , Diazabicyclo structure, onium hydroxide structure, onium carboxylate structure, trialkylamine structure, aniline structure or pyridine structure compound, alkylamine derivative having hydroxyl group and / or ether bond, aniline derivative having hydroxyl group and / or ether bond Etc.

  Examples of the compound having an imidazole structure include imidazole, 2,4,5-triphenylimidazole, and benzimidazole. Examples of the compound having a diazabicyclo structure include 1,4-diazabicyclo [2,2,2] octane, 1,5-diazabicyclo [4,3,0] non-5-ene, and 1,8-diazabicyclo [5,4. 0] Undecaker 7-ene and the like. Examples of the compound having an onium hydroxide structure include triarylsulfonium hydroxide, phenacylsulfonium hydroxide, sulfonium hydroxide having a 2-oxoalkyl group, specifically, triphenylsulfonium hydroxide, tris (t-butylphenyl) Examples include sulfonium hydroxide, bis (t-butylphenyl) iodonium hydroxide, phenacylthiophenium hydroxide, and 2-oxopropylthiophenium hydroxide. As a compound which has an onium carboxylate structure, the anion part of the compound which has an onium hydroxide structure turns into a carboxylate, For example, an acetate, an adamantane 1-carboxylate, a perfluoroalkyl carboxylate etc. are mentioned. Examples of the compound having a trialkylamine structure include tri (n-butyl) amine and tri (n-octyl) amine. Examples of the compound having an aniline structure include 2,6-diisopropylaniline, N, N-dimethylaniline, N, N-dibutylaniline, N, N-dihexylaniline and the like. Examples of the alkylamine derivative having a hydroxyl group and / or an ether bond include ethanolamine, diethanolamine, triethanolamine, and tris (methoxyethoxyethyl) amine. Examples of aniline derivatives having a hydroxyl group and / or an ether bond include N, N-bis (hydroxyethyl) aniline.

  Preferred examples of the basic compound further include an amine compound having a phenoxy group, an ammonium salt compound having a phenoxy group, an amine compound having a sulfonic acid ester group, and an ammonium salt compound having a sulfonic acid ester group. Specific examples thereof include compounds (C1-1) to (C3-3) exemplified in [0066] of US Patent Application Publication No. 2007/0224539, but are not limited thereto. Absent.

  The resin composition (1) may or may not contain the compound (N ′), but when it is contained, the content of the compound (N ′) is determined based on the solid content of the resin composition (1). As a reference | standard, 0.001-10 mass% is preferable, More preferably, it is 0.01-5 mass%.

  (3) In another embodiment, the resin composition (1) is a nitrogen-containing organic compound having a group capable of leaving by the action of an acid (hereinafter referred to as “basic compound (N ″)) as one type of basic compound. May also be included. As an example of this compound, for example, specific examples of the compound are shown below.

The said compound is compoundable according to the method as described in Unexamined-Japanese-Patent No. 2009-199021, for example.

  As the basic compound (N ″), a compound having an amine oxide structure can also be used. Specific examples of this compound include triethylamine pyridine N-oxide, tributylamine N-oxide, triethanolamine N-oxide, tris (methoxyethyl) amine N-oxide, tris (2- (methoxymethoxy) ethyl) amine = oxide. 2,2 ′, 2 ″ -nitrilotriethylpropionate N-oxide, N-2- (2-methoxyethoxy) methoxyethylmorpholine N-oxide, and other amine oxide compounds exemplified in JP-A-2008-102383 are used. Is possible.

  The molecular weight of the basic compound (N ″) is preferably 250 to 2000, and more preferably 400 to 1000. From the viewpoint of further reduction in LWR and uniformity of local pattern dimensions, the molecular weight of the basic compound is preferably 400 or more, more preferably 500 or more, and even more preferably 600 or more. .

  These basic compounds (N ″) may be used in combination with the compound (N), or may be used alone or in combination of two or more.

  The resin composition (1) in the present invention may or may not contain the basic compound (N ″), but when it is contained, the amount of the basic compound (N ″) used is the resin composition. Based on the solid content of (1), it is usually 0.001 to 10% by mass, preferably 0.01 to 5% by mass.

  (4) In another form, the resin composition (1) may contain an onium salt represented by the following general formula (6A) or (6B) as a basic compound. This onium salt is expected to control the diffusion of the generated acid in the resist system in relation to the acid strength of the photoacid generator usually used in the resist composition.

In general formula (6A),
Ra represents an organic group. However, those in which a fluorine atom is substituted for a carbon atom directly bonded to a carboxylic acid group in the formula are excluded.

X ⁺ represents an onium cation.

In general formula (6B),
Rb represents an organic group. However, those in which a fluorine atom is substituted for a carbon atom directly bonded to the sulfonic acid group in the formula are excluded.

X ⁺ represents an onium cation.

  In the organic group represented by Ra and Rb, the atom directly bonded to the carboxylic acid group or sulfonic acid group in the formula is preferably a carbon atom. However, in this case, in order to make the acid relatively weaker than the acid generated from the above-mentioned photoacid generator, the fluorine atom does not substitute for the carbon atom directly bonded to the sulfonic acid group or carboxylic acid group.

  Examples of the organic group represented by Ra and Rb include an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, and an aralkyl group having 7 to 30 carbon atoms. Or a C3-C30 heterocyclic group etc. are mentioned. In these groups, some or all of the hydrogen atoms may be substituted.

  Examples of the substituent that the alkyl group, cycloalkyl group, aryl group, aralkyl group and heterocyclic group may have include a hydroxyl group, a halogen atom, an alkoxy group, a lactone group, and an alkylcarbonyl group.

Examples of the onium cation represented by X ⁺ in the general formulas (6A) and (6B) include a sulfonium cation, an ammonium cation, an iodonium cation, a phosphonium cation, and a diazonium cation. Among these, a sulfonium cation is more preferable.

  As the sulfonium cation, for example, an arylsulfonium cation having at least one aryl group is preferable, and a triarylsulfonium cation is more preferable. The aryl group may have a substituent, and the aryl group is preferably a phenyl group.

  As an example of a sulfonium cation and an iodonium cation, the structure demonstrated in the compound (B) can also be mentioned preferably.

  A specific structure of the onium salt represented by the general formula (6A) or (6B) is shown below.

The resin composition (1) may or may not contain the onium salt, but when it is contained, the content of the onium salt is 0 based on the solid content of the resin composition (1). 0.001 to 20% by mass is preferable, and 0.01 to 10% by mass is more preferable.

  (5) In another form, the resin composition (1) is a compound included in the formula (I) of JP2012-189977A, the formula (I) of JP2013-6827A as a basic compound. In one molecule, such as a compound represented by formula (I) in JP2013-8020A, a compound represented by formula (I) in JP2012-252124A, and the like A compound having both an onium salt structure and an acid anion structure (hereinafter also referred to as a betaine compound) may also be contained. Examples of the onium salt structure include a sulfonium, iodonium, and ammonium structure, and a sulfonium or iodonium salt structure is preferable. The acid anion structure is preferably a sulfonate anion or a carboxylic acid anion. Examples of this compound include the following.

The resin composition (1) may or may not contain the betaine compound, but when it is contained, the content of the betaine compound is 0 based on the solid content of the resin composition (1). 0.001 to 20% by mass is preferable, and 0.01 to 10% by mass is more preferable.

[6] Surfactant The resin composition (1) may further contain a surfactant. When the resin composition (1) contains a surfactant, fluorine and / or silicon surfactant (fluorine surfactant, silicon surfactant, surfactant having both fluorine atom and silicon atom) It is more preferable to contain any one of these or 2 or more types.

  When the resin composition (1) contains a surfactant, it is possible to provide a resist pattern with less adhesion and development defects with good sensitivity and resolution when using an exposure light source of 250 nm or less, particularly 220 nm or less. It becomes.

  Examples of the fluorine-based and / or silicon-based surfactant include surfactants described in [0276] of US Patent Application Publication No. 2008/0248425. For example, Fluorard FC430, 431, 4430 (Sumitomo 3M) ), Megafuck Series (manufactured by DIC Corporation), Surflon S-382, SC101, 102, 103, 104, 105, 106, KH-20 (manufactured by Asahi Glass Co., Ltd.), Troisol S-366 (Troy Chemical ( GF-300, GF-150 (manufactured by Toagosei Co., Ltd.), Surflon S-393 (manufactured by Seimi Chemical Co., Ltd.), EFtop EF121, EF122A, EF122B, RF122C, EF125M, EF135M, EF351 , EF352, EF801, EF802, EF601 (Jet Corporation) Ltd. co), PF636, PF656, PF6320, PF6520, and the like (manufactured by OMNOVA Inc.), FTX-204G, 208G, 218G, 230G, 204D, 208D, 212D, 218D, 222D ((KK) Neos). Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

  In addition to the known surfactants described above, surfactants are derived from fluoroaliphatic compounds produced by the telomerization method (also referred to as the telomer method) or the oligomerization method (also referred to as the oligomer method). A surfactant using a polymer having a fluoroaliphatic group can be used. The fluoroaliphatic compound can be synthesized by the method described in JP-A-2002-90991.

As the surfactant corresponding to the above, Megafac F178, F-470, F-473, F-475, F-476, F-472 (manufactured by DIC Corporation), acrylate having C ₆ F ₁₃ group (or methacrylate) and (poly (oxyalkylene)) acrylate (copolymer of or methacrylate), and acrylate having a C ₃ F ₇ group (or methacrylate) (poly (oxyethylene) and) acrylate (or methacrylate) (poly ( And a copolymer with oxypropylene)) acrylate (or methacrylate).

  In the present invention, surfactants other than fluorine-based and / or silicon-based surfactants described in [0280] of US Patent Application Publication No. 2008/0248425 can also be used.

  These surfactants may be used alone or in several combinations.

  When the resin composition (1) contains a surfactant, the amount of the surfactant used is preferably 0.0001 to 2% by mass with respect to the total amount of the resin composition (1) (excluding the solvent). More preferably, it is 0.0005-1 mass%.

  On the other hand, by making the addition amount of the surfactant 10 ppm or less with respect to the total amount of the resin composition (1) (excluding the solvent), the surface unevenness of the hydrophobic resin is increased. Can be made more hydrophobic, and the water followability during immersion exposure can be improved.

[7] Other additives (G)
The resin composition (1) may contain a carboxylic acid onium salt. Examples of such carboxylic acid onium salts include those described in US Patent Application Publication No. 2008/0187860 [0605] to [0606].

  When resin composition (1) contains carboxylic acid onium salt, the content rate is generally 0.1-20 mass% with respect to the total solid of resin composition (1), Preferably it is 0.00. It is 5-10 mass%, More preferably, it is 1-7 mass%.

  Moreover, the resin composition (1) may contain what is called an acid proliferating agent as needed. The acid proliferating agent is particularly preferably used when performing the pattern forming method of the present invention by EUV exposure or electron beam irradiation. Although it does not specifically limit as a specific example of an acid multiplication agent, For example, the following is mentioned.

If necessary, the resin composition (1) may further include a dye, a plasticizer, a photosensitizer, a light absorber, an alkali-soluble resin, a dissolution inhibitor, and a compound that promotes solubility in a developer (for example, a molecular weight of 1000 The following phenol compounds, alicyclic or aliphatic compounds having a carboxyl group, and the like can be contained.
<Actinic ray-sensitive or radiation-sensitive resin composition (2)>
Next, the actinic ray-sensitive or radiation-sensitive resin composition (2) used in step (ii) of the mask layer forming step (a1) by photolithography (also simply referred to as “resin composition (2)”) Will be described.

  The actinic ray-sensitive or radiation-sensitive resin composition (2) is typically a resist composition like the actinic ray-sensitive or radiation-sensitive resin composition (1), and is a negative resist composition ( That is, a resist composition for organic solvent development). The actinic ray-sensitive or radiation-sensitive resin composition (2) is typically a chemically amplified resist composition.

  The actinic ray-sensitive resin composition (2) preferably contains a resin whose polarity is increased by the action of an acid and whose solubility in a developer containing an organic solvent is reduced. The thing similar to resin (A) demonstrated in the thing (1) can be mentioned. The preferable range of the resin content with respect to the total solid content of the resin composition (1) is also the same as that described in the resin composition (1).

  Moreover, the resin composition (2) can similarly contain each of the above components that the resin composition (1) can contain, and the preferred range of the content of each component in the composition is also the resin composition. This is the same as described in (1).

  The solid content concentration of the resin compositions (1) and (2) is usually 1.0 to 10% by mass, preferably 2.0 to 5.7% by mass, and more preferably 2.0 to 5.3%. % By mass. By setting the solid content concentration within the above range, the resist solution can be uniformly applied on the substrate.

  The solid content concentration is a mass percentage of the mass of other resist components excluding the solvent with respect to the total mass of the actinic ray-sensitive or radiation-sensitive resin composition.

  The resin compositions (1) and (2) are used by dissolving the above components in a predetermined organic solvent, preferably the above mixed solvent, filtering the solution, and applying the solution on a predetermined support (substrate). The pore size of the filter used for filter filtration is preferably 0.1 μm or less, more preferably 0.05 μm or less, and still more preferably 0.03 μm or less made of polytetrafluoroethylene, polyethylene, or nylon. In filter filtration, for example, as in JP-A-2002-62667, circulation filtration may be performed, or filtration may be performed by connecting a plurality of types of filters in series or in parallel. Moreover, you may filter resin composition (1) and (2) in multiple times. Furthermore, you may perform a deaeration process etc. with respect to resin composition (1) and (2) before and after filter filtration.

  The resin composition (1) and the resin composition (2) may be the same as or different from each other. When the exposure light source in the step (ii-2) and the exposure light source in the step (i-2) are the same, the resin composition (1) and the resin composition (2) are preferably the same.

  It should be noted that both intermixes are less likely to be a problem when, for example, the first negative pattern is formed in step (i-3) and then thermosetting (heating) as in the heating step (iii) is performed. It can be considered, but this does not preclude resist design in consideration of intermix problems.

In order to suppress the intermix, for example, as a solvent contained in the resin composition (2), a solvent that dissolves the resin of the resin composition (2) but does not dissolve the resin of the resin composition (1). It is possible to choose. For such a design, for example, the solvent contained in the resin composition (2) includes the solvents mentioned above as the rinse liquid containing an organic solvent. Preferable examples can be given.
<Mask layer forming step (a2) by imprint method>
The formation of the mask layer having a multistage structure mask pattern in the step (a) can also be performed by an imprint method using a mold (step (a2)). In the imprint method, it is possible to collectively transfer a three-dimensional structure pattern formed on a mold.

  The step (a2) by the imprint method includes a step of applying a resist on a laminated substrate in which a substrate, a first processing target layer, an etching stopper layer, and a second processing target layer are stacked in this order, the resist film A step of pressing the multi-stage mold (pressing step), a step of curing the resist film in the close contact state, and a step of peeling the multi-stage mold from the cured resist film.

(mold)
In the step (a2) by the imprint method, as a mold, a mold provided with a pattern having a multi-stage projecting portion whose width gradually decreases from the bottom toward the top (hereinafter also referred to as “multi-stage mold”). ) Is used.

  This multi-stage mold can be formed by a known method. For example, a quartz mold obtained by the following method can be used.

  First, a PHS (polyhydroxy styrene) -based chemically amplified resist, a novolac-based resist, a resist solution mainly composed of an acrylic resin such as PMMA (polymethyl methacrylate), etc. is applied onto a quartz substrate by spin coating, A resist layer is formed. Next, the quartz substrate is irradiated with laser light (or an electron beam) while being modulated corresponding to the desired concavo-convex pattern, and the concavo-convex pattern is exposed on the resist layer surface. Thereafter, the resist layer is developed, and selective etching is performed by reactive ion etching (RIE) using the developed resist layer pattern as a mask to obtain a quartz mold having a predetermined uneven pattern.

  The mold may have a mesa structure including a mesa portion (a portion whose upper surface is relatively flat and higher than the periphery) and a flange portion around the mesa portion. The step of the mesa portion is preferably 1-1000 μm, more preferably 10-500 μm, and still more preferably 20-100 μm. When nanoimprinting is performed using a mesa mold, the contact area between the mold and the resist is reduced compared to when using a flat mold, and the mold can be removed from the resist with a small force. There is. For example, when a pattern is repeatedly transferred (step-and-repeat) to the same substrate, a mesa-type mold is used so that the next pattern is transferred to the mold first. There is also an advantage that the previously transferred pattern can be prevented from being crushed by interference with the pattern.

(Release processing)
In the present invention, in order to improve the releasability between the resist and the mold surface, it is preferable to perform a release treatment on the uneven pattern surface of the mold. As the mold release agent used for the mold release treatment, Opkin (registered trademark) DSX manufactured by Daikin Industries, Ltd., Novec (registered trademark) EGC-1720 manufactured by Sumitomo 3M Co., Ltd., and the like are used as fluorine-based silane coupling agents. .

  In addition, known fluorine resins, hydrocarbon lubricants, fluorine lubricants, fluorine silane coupling agents, and the like can be used.

For example, PTFA (polytetrafluoroethylene), PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer), FEP (tetrafluoroethylene / hexafluoropropylene copolymer), ETFE (tetrafluoroethylene Ethylene copolymer).
For example, hydrocarbon lubricants include carboxylic acids such as stearic acid and oleic acid, esters such as butyl stearate, sulfonic acids such as octadecyl sulfonic acid, phosphate esters such as monooctadecyl phosphate, stearyl alcohol and oleyl Examples thereof include alcohols such as alcohol, carboxylic acid amides such as stearamide, and amines such as stearylamine.
For example, examples of the fluorine-based lubricant include a lubricant in which part or all of the alkyl group of the hydrocarbon-based lubricant is substituted with a fluoroalkyl group or a perfluoropolyether group.

For example, as the perfluoropolyether group, a perfluoromethylene oxide polymer, a perfluoroethylene oxide polymer, a perfluoro-n-propylene oxide polymer (CF ₂ CF ₂ CF ₂ O) n, a perfluoroisopropylene oxide polymer ( CF (CF ₃ ) CF ₂ O) _n or a copolymer thereof. Here, the subscript n represents the degree of polymerization.

For example, the fluorinated silane coupling agent has at least 1, preferably 1 to 10, alkoxysilane groups and chlorosilane groups in the molecule, and preferably has a molecular weight of 200 to 10,000. For example, the alkoxysilane group, -Si _{(OCH 3)} 3 _{group, -Si (OCH 2 CH 3)} 3 group. Examples of the chlorosilane group, and a -Si _{(Cl) 3} group. Specifically, heptadecafluoro-1,1,2,2-tetra-hydrodecyltrimethoxysilane, pentafluorophenylpropyldimethylchlorosilane, tridecafluoro-1,1,2,2-tetra-hydrooctyltriethoxy Compounds such as silane and tridecafluoro-1,1,2,2-tetra-hydrooctyltrimethoxysilane.

(Resist)
The resist is not particularly limited, but in the present embodiment, for example, a polymerizable compound, a photopolymerization initiator (for example, about 0.1 to 2% by mass), a fluorine-containing monomer (for example, 0.1 to 1). A photo-curable resist prepared by adding (mass%) can be used.

  Moreover, antioxidant (for example, about 0.1-1 mass%) can also be added as needed. The resist prepared by the above procedure can be cured by ultraviolet light having a wavelength of 360 nm. For those having poor solubility, it is preferable to add a small amount of acetone or ethyl acetate for dissolution, and then distill off the solvent.

Examples of the polymerizable compound include benzyl acrylate (Biscoat (registered trademark) # 160: manufactured by Osaka Organic Chemical Co., Ltd.), ethyl carbitol acrylate (Biscoat (registered trademark) # 190: manufactured by Osaka Organic Chemical Co., Ltd.), polypropylene glycol di In addition to acrylate (Aronix (registered trademark) M-220: manufactured by Toagosei Co., Ltd.), trimethylolpropane PO-modified triacrylate (Aronix (registered trademark) M-310: manufactured by Toagosei Co., Ltd.), etc. The compound A etc. which are represented can be mentioned.
Structural formula 1:

As the polymerization initiator, 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone (IRGACURE (registered trademark)) 379: manufactured by Toyotsu Chemiplus Co., Ltd.) and the like.

Examples of the fluorine-containing monomer include compound B represented by the following structural formula 2.
Structural formula 2:

For example, the viscosity of the resist material is 8 to 20 cP, and the surface energy of the resist material is 25 to 35 mN / m. Here, the viscosity of the resist material is a value measured at 25 ± 0.2 ° C. using a RE-80L rotational viscometer (manufactured by Toki Sangyo Co., Ltd.). The rotational speed at the time of measurement was 100 rpm when 0.5 cP or more and less than 5 cP, 50 rpm when 5 cP or more and less than 10 cP, 20 rpm when 10 cP or more and less than 30 cP, and 10 rpm when 30 cP or more and less than 60 cP. The surface energy of resist materials is “UV nanoimprint materials: Surface energies, residual layers, and imprint quality”, H. Schmitt, L. Frey, H. Ryssel, M. Rommel, C. Lehrer, J. Vac. Sci. Technol. B, Volume 25, Issue 3, 2007, Pages 785-790. Specifically, the surface energy of each of the Si substrate that has been subjected to UV ozone treatment and the Si substrate that has been surface-treated by OPTOOL (registered trademark) DSX (manufactured by Daikin Corporation) is obtained, and the resist is determined from the contact angle of the resist material with respect to both substrates. The surface energy of the material was calculated.

  Further, a compound having a strong intermolecular interaction and low volatility (for example, a surfactant) may be added. In this case, when the resist is applied, a large amount of the compound is distributed at the gas-liquid interface of the resist, and a film covering the resist surface is formed. It is done. This is particularly effective in suppressing volatilization of a polymerizable compound which is a main component of the resist and has high volatility.

(Resist application method)
As a method for applying the resist to the laminated substrate, a method capable of arranging a predetermined amount of droplets at a predetermined position on the substrate or mold, such as an ink jet method or a dispensing method, or a uniform film such as a spin coating method or a dip coating method. A method capable of applying a resist with a thickness can be used. In the case where a uniform thin film is formed on a substrate by spin coating or the like, it is difficult to control the film thickness in accordance with a concavo-convex pattern which will be described later. In addition, the arrangement of minute droplets rather than a uniform thin film reduces the area of the gas-liquid interface when the same volume of resist is applied, and the influence of volatilization of the resist material can be reduced.

  When placing resist droplets on the laminated substrate, an ink jet printer or a dispenser may be used depending on the desired droplet amount. For example, there are methods such as using an ink jet printer when the amount of droplets is less than 100 nl, and using a dispenser when the amount is 100 nl or more.

  Examples of the inkjet head that discharges the resist from the nozzle include a piezo method, a thermal method, and an electrostatic method. Among these, a piezo method capable of adjusting an appropriate amount of liquid (amount per droplet disposed) and a discharge speed is preferable. Before disposing the resist droplets on the substrate, the droplet amount and ejection speed are adjusted in advance. For example, the appropriate amount of liquid may be increased at a position on the substrate corresponding to a region where the space volume of the concave / convex pattern of the mold is large, or may be decreased at a position on the substrate corresponding to a region where the spatial volume of the concave / convex pattern of the mold is small. It is preferable to adjust. Such adjustment is appropriately controlled according to the droplet discharge amount (the amount per discharged droplet). Specifically, when the droplet amount is set to 5 pl, the droplet amount is controlled to be ejected to the same place five times using an inkjet head having a droplet ejection amount of 1 pl. The amount of droplets can be obtained, for example, by measuring the three-dimensional shape of droplets discharged on the substrate under the same conditions in advance with a confocal microscope or the like and calculating the volume from the shape.

  After adjusting the droplet amount as described above, droplets are arranged on the substrate according to a predetermined droplet arrangement pattern. The droplet arrangement pattern is configured by two-dimensional coordinate information including a lattice point group corresponding to the droplet arrangement on the substrate.

(Pressing process)
Before contacting the mold and the resist, it is preferable to reduce the residual gas by reducing the atmosphere between the mold and the laminated substrate coated with the resist to a reduced pressure or vacuum atmosphere. However, in a high vacuum atmosphere, the resist before curing is volatilized and it may be difficult to maintain a uniform film thickness. Therefore, the residual gas is preferably reduced by setting the atmosphere between the mold and the laminated substrate to a He atmosphere or a reduced pressure He atmosphere. Since He permeates the quartz substrate, the trapped residual gas (He) gradually decreases. Since it takes time to permeate He, it is more preferable to use a reduced pressure He atmosphere. The reduced pressure atmosphere is preferably 1 to 90 kPa, and particularly preferably 1 to 10 kPa.

  The laminated substrate on which the resist is formed and the mold are brought into contact with each other after they are aligned so as to have a predetermined relative positional relationship. An alignment mark is preferably used for alignment. The alignment mark is formed in a concavo-convex pattern that can be detected by an optical microscope, moire interferometry, or the like. The alignment accuracy is preferably 10 μm or less, more preferably 1 μm or less, and still more preferably 100 nm or less.

  The pressing pressure of the mold is preferably performed in the range of 100 kPa to 10 MPa. When the pressure is larger, it is easier to make the surface shapes of the mold and the laminated substrate follow each other, and the resist flow is promoted. Furthermore, when the pressure is high, removal of residual gas, compression, dissolution of the residual gas into the resist, and transmission of He through the quartz substrate are promoted, leading to an improvement in the quality of the resist pattern. However, if the applied pressure is too strong, there is a possibility that the mold and the substrate may be damaged when a foreign object is caught in the mold. Therefore, the pressing pressure of the mold is preferably 100 kPa to 5 MPa, and particularly preferably 100 kPa to 1 MPa. The reason why the pressure is set to 100 kPa or more is that when imprinting is performed in the atmosphere, when the space between the mold and the substrate is filled with liquid, the pressure between the mold and the laminated substrate is pressurized at atmospheric pressure (about 101 kPa). .

(Curing process)
After forming the resist film by pressing the mold, for example, the resist is cured by exposure with light containing a wavelength that matches the polymerization initiator contained in the resist.

(Peeling process)
As a method for releasing after curing, for example, holding the back surface or outer edge portion of either the mold or the laminated substrate and holding the back surface or outer edge portion of the other laminated substrate or mold, holding the outer edge holding portion or back surface. A method of relatively moving the holding portion in the direction opposite to the pressing can be mentioned.

  In addition, although said embodiment demonstrated the case of the photocurable resist, this invention is not limited to this. That is, in this invention, it is also possible to use a thermosetting resin, for example.

  FIG. 1C shows an example of a stacked body obtained in this step (a2) in which a mask layer having a multi-stage structure mask pattern having a multi-stage recess is formed on a substrate. In FIG. 1C, a laminated body 100C includes a laminated substrate 110C, and a mask having a mask pattern including a multi-stage recessed portion 10C composed of a first recessed portion 11C and a second recessed portion 12C on the laminated substrate 110C. Layer 120C is provided.

  In the laminated body 100C, the laminated substrate 110C includes a substrate 3C, a second etching stopper layer 2C, a first processing target layer 20C, a first etching stopper layer 1C, and a second processing target layer 30C that are stacked in this order. Yes.

<< Step (b): Etching Process for Transferring Mask Pattern Shape >>
Next, using the mask layer having the multistage structure mask pattern formed as described above as a mask, the substrate is etched to transfer the shape of the multistage structure mask pattern (step (b)).

  For example, the etching process described below is performed on the stacked substrate 110D using the mask layer 120D having the multi-stage structure mask pattern 120D shown in FIGS. 2D and 3D as a mask. It corresponds to the hole part (first recess 11D) of the first negative pattern 40D and the space part (second recess 12D) of the second negative pattern 50D shown in e) and 3 (e). A stepped substrate 210D having a perforated position is obtained.

  The method for the etching treatment is not particularly limited, and any known method can be used, and various conditions and the like are appropriately determined according to the type and use of the substrate. For example, Proc. Of SPIE Vol. 6924, 692420 (2008), Japanese Patent Application Laid-Open No. 2009-267112, and the like can be performed.

  In the method for manufacturing a stepped substrate of the present invention, the etching process step (b) for transferring the multistage structure mask pattern to the substrate includes the following steps in one embodiment.

(B1) a step of transferring the shape of the first recess to the second processing target layer by the first etching;
(B2) transferring the shape of the first recess to the etching stopper layer by second etching;
(B3) transferring the shape of the first recess to the first processing target layer by the third etching; and (b4) transferring the shape of the second recess to the second processing target layer by the fourth etching. Process.

  As described above, in the method for manufacturing a stepped substrate according to the present invention, the etching stopper layer is interposed between the two processing target layers, so that the shoulders of the corners of the multi-stage structure in the concave portion of the processing target layer, the dimensional variation, Since generation of variations in processing depth can be suppressed, a mask pattern having a multi-stage structure can be transferred to a processing target layer with high accuracy.

  In one embodiment, the etching process step (b) includes the step (b1), the step (b2), the step (b3), and the step (b4) in the order described, but is not limited thereto. Absent. For example, the step (b3) and the step (b4) may be performed simultaneously under the same etching process conditions.

  Further, for example, the etching processing conditions in the step (b1) and the step (b2) may be the same, and the etching processing may be performed collectively.

  Hereinafter, the etching process (b) will be described with reference to FIGS.

4A to 4I are schematic cross-sectional views for explaining a method of manufacturing a stepped substrate according to an embodiment of the present invention, in which FIGS. 4C to 4H are illustrated. These respectively show one form of an etching process process (b).
4B is a stacked body having the same structure as the stacked body 100B illustrated in FIG. 1B. Therefore, the substrate 3E, the second etching stopper layer 2E, the first processing target layer 20E, the first etching stopper layer 1E, and the second processing target layer 30E in the stacked substrate 110E of the stacked body 100E are respectively The same as the substrate 3B, the second etching stopper layer 2B, the first processing target layer 20B, the first etching stopper layer 1B, and the second processing target layer 30B in the stacked body 100B of FIG. 1B. Further, the antireflection film 60E of the multilayer body 100E is the same as the antireflection film 60B in the multilayer body 100B of FIG. 1B. Further, the first negative pattern 40E and the second negative pattern 50E in the mask layer 120E of the stacked body 100E are the first negative pattern 40B and the second negative pattern 50B in the stacked body 100B in FIG. 1B. It is the same as the mold pattern 50B.

  Through the steps (b0), (b1), (b2), (b3), (b3 ′), (b4), and (b5) described below, the first recess 11E and the second in the mask layer 120E The shape of the recess 10E having a multi-stage structure including the recess 12E is transferred to the substrate 110E.

[Step (b0)]
A laminated body 100E shown in FIG. 4B includes an antireflection film 60E which is an arbitrary constituent member between the laminated substrate 110E and the mask layer 120E. Therefore, in the etching process step (b) described with reference to FIG. 4, the antireflection film 60E is etched before the step (b1) to transfer the shape of the first recess 11E in the mask layer 120E. Including a step (b0). Thereby, the structure shown in FIG. 4C is obtained.

[Step (b1)]
Next, the second processing target layer 30E of the structure shown in FIG. 4C is etched to transfer the shape of the first recess 11E in the mask layer 120E (step (b1)). Thereby, the structure shown in FIG. 4D is obtained.

[Step (b2)]
Next, the first etching stopper layer 1E of the structure shown in FIG. 4D is etched to transfer the shape of the first recess 11E in the mask layer 120E (step (b2)). Thereby, the structure shown in FIG.

[Step (b3)]
Next, the first processing target layer 20E of the structure shown in FIG. 4E is etched to transfer the shape of the first recess 11E in the mask layer 120E (step (b3)). Thereby, the structure shown in FIG.

[Step (b3 ′)]
In the structure shown in FIG. 4F, the first recess 11E in the mask layer 120E remains, and the antireflection film 60E is provided. Therefore, in the etching process step (b) described with reference to FIG. 4, after the step (b3), the remaining first recess 11E in the mask layer 120E and the antireflection film 60E are subjected to an etching process, and the mask A step (b3 ′) of transferring the shape of the second recess 12E in the layer 120E. As a result, the structure shown in FIG.

  In the structure obtained by obtaining the step (b3), when the first recess 11E in the mask layer 120E does not remain and the antireflection film 60E does not exist, the etching treatment step (b) The step (b3 ′) is not included.

[Step (b4)]
Next, the second processing target layer 30E is etched to transfer the shape of the second recess 12E in the mask layer 120E (step (b4)). Thereby, the structure shown in FIG.

[Step (b5)]
Next, oxygen plasma ashing is performed on the remaining mask layer 120E (40E) and the antireflection film 60E, and the mask layer 120E and the antireflection film 60E are peeled off. As a result, a stepped substrate 210E having a multistage structure pattern shown in FIG.

FIGS. 5A to 5H are schematic cross-sectional views for explaining a method of manufacturing a stepped substrate according to another embodiment of the present invention, in which FIGS. ) Respectively show one form of the etching process step (b).
A laminate 100F in FIG. 5B is a laminate having the same structure as the laminate 100B illustrated in FIG. 1B. Therefore, the substrate 3F, the second etching stopper layer 2F, the first processing target layer 20F, the first etching stopper layer 1F, and the second processing target layer 30F in the stacked substrate 110F of the stacked body 100F are respectively It is the same as the substrate 3B, the second etching stopper layer 2B, the first processing target layer 20B, the first etching stopper layer 1B, and the second processing target layer 30B in the stacked body 100B of FIG. 1B. Further, the antireflection film 60F of the multilayer body 100F is the same as the antireflection film 60B in the multilayer body 100B of FIG. 1B. Further, the first negative pattern 40F and the second negative pattern 50F in the mask layer 120F of the stacked body 100F are the first negative pattern 40B and the second negative pattern in the stacked body 100B in FIG. 1B. It is the same as the mold pattern 50B.

  Through the steps (b0), (b1), (b2), (b3 ′), (b3-b4), and (b5) described below, the first recess 11F and the second recess 12F in the mask layer 120F. The shape of the concave portion 10F having a multistage structure is transferred to the laminated substrate 110F.

[Step (b0)]
Since the laminated body 100F shown in FIG. 5B includes an antireflection film 60F, which is an optional constituent member, between the laminated substrate 110F and the mask layer 120F, an etching process step (b) described based on FIG. As in the etching process step (b) described with reference to FIG. 4, before the step (b1), the antireflection film 60F is etched to transfer the shape of the first recess 11F in the mask layer 120F. Including a step (b0). Thereby, the structure shown in FIG. 5C is obtained.

[Step (b1)]
Next, the second processing target layer 30F of the structure shown in FIG. 5C is etched to transfer the shape of the first recess 11F in the mask layer 120F (step (b1)). Thereby, the structure shown in FIG. 5D is obtained.

[Step (b2)]
Next, the first etching stopper layer 1F of the structure shown in FIG. 5D is etched to transfer the shape of the first recess 11F in the mask layer 120F (step (b2)). Thereby, the structure shown in FIG.

[Step (b3 ′)]
In the structure shown in FIG. 5E, the first concave portion 11F in the mask layer 120F remains, and the antireflection film 60F is provided. Therefore, in the etching process step (b) described with reference to FIG. 5, after the step (b2), the remaining first concave portion 11F in the mask layer 120F and the antireflection film 60F are etched, and the mask A step (b3 ′) of transferring the shape of the second recess 12F in the layer 120F. Thereby, the structure shown in FIG.

  In the structure obtained by obtaining the step (b2), when the first recess 11F in the mask layer 120F does not remain and the antireflection film 60F does not exist, the etching treatment step (b) is a step. (B3 ′) is not included.

[Step (b3-b4)]
In the etching process step (b) described based on FIG. 5, the step (b3) and the step (b4) described above are performed simultaneously (step (b3-b4)).

  That is, the first processing target layer 20F and the second processing target layer 30F of the structure shown in FIG. 5F are simultaneously etched under the same etching processing conditions. In other words, transfer of the shape of the first recess 11F in the mask layer 120F to the first processing target layer 20F, and transfer of the shape of the second recess 12F in the mask layer 120F to the second processing target layer 30F. Are collectively performed by a single etching process (steps (b3-b4)). As a result, the structure shown in FIG. 5G is obtained, in which the multi-stage recess 10F in the mask layer 120F is transferred.

[Step (b5)]
Next, oxygen plasma ashing is performed on the remaining mask layer 120F (40F) and the antireflection film 60F, and the mask layer 120F and the antireflection film 60F are peeled off. As a result, a stepped substrate 210E having a multistage structure pattern shown in FIG.

6A to 6G are schematic cross-sectional views for explaining a method for manufacturing a stepped substrate according to another embodiment of the present invention, in which FIGS. ) Respectively show one form of the etching process step (b).
A stacked body 100G in FIG. 6B is a stacked body having the same structure as the stacked body 100B illustrated in 1B. Accordingly, the substrate 3G, the second etching stopper layer 2G, the first processing target layer 20G, the first etching stopper layer 1G, and the second processing target layer 30G in the stacked substrate 110G of the stacked body 100G are as shown in FIG. The same as the substrate 3B, the second etching stopper layer 2B, the first processing target layer 20B, the first etching stopper layer 1B, and the second processing target layer 30B in the stacked body 100B. Further, the antireflection film 60G of the multilayer body 100G is the same as the antireflection film 60B in the multilayer body 100B of FIG. 1B. The first negative pattern 40G and the second negative pattern 50G in the mask layer 120G of the stacked body 100G are the first negative pattern 40B and the second negative pattern in the stacked body 100B in FIG. 1B. It is the same as the mold pattern 50B.

  After the steps (b0), (b1-b2), (b3 ′), (b3-b4), and (b5) described below, the mask layer 120G includes the first recess 11G and the second recess 12G. The shape of the multi-stage recess 10G is transferred to the laminated substrate 110G.

[Step (b0)]
Since the laminated body 100G shown in FIG. 6B includes an antireflection film 60G which is an arbitrary constituent member between the laminated substrate 110G and the mask layer 120G, an etching process step (b) described based on FIG. As in the etching process step (b) described with reference to FIGS. 4 and 5, before the step (b1), the antireflection film 60G is etched to change the shape of the first recess 11G in the mask layer 120G. A transferring step (b0). Thereby, the structure shown in FIG. 6C is obtained.

[Step (b1-b2)]
In the etching process (b) described with reference to FIG. 6, the above-described process (b1) and process (b2) are collectively performed under the same etching process conditions (process (b1-b2)).

  That is, the first recess 11G in the mask layer 120G is transferred to the second processing target layer 30G of the structure shown in FIG. 6C, and the first in the mask layer 120G is transferred to the first etching stopper layer 1G. The transfer of the concave portion 11G is performed collectively by one etching process (step (b1-b2)). Thereby, the structure shown in FIG. 6D is obtained.

[Step (b3 ′)]
In the structure shown in FIG. 6D, the antireflection film 60G remains. For this reason, the etching process step (b) described based on FIG. 6 performs the etching process on the remaining antireflection film 60G after the step (b1-b2), and the shape of the second recess 12G in the mask layer 120G. (B3 ′). Thereby, the structure shown in FIG.

  In the structure obtained by obtaining the step (b1-b2), when the first recess 11G in the mask layer 120G does not remain and the antireflection film 60G does not exist, the etching treatment step (b) Does not include the step (b3 ′).

[Step (b3-b4)]
In the etching process step (b) described based on FIG. 6, the step (b3) and the step (b4) described above are performed simultaneously (step (b3) as in the etching process step (b) described based on FIG. -B4)).

  That is, the first processing target layer 20G and the second processing target layer 30G in the structure shown in FIG. 6E are simultaneously etched under the same etching processing conditions. In other words, transfer of the shape of the first recess 11G in the mask layer 120G to the first processing target layer 20G, and transfer of the shape of the second recess 12G in the mask layer 120G to the second processing target layer 30G. Are collectively performed by a single etching process (steps (b3-b4)). As a result, the structure shown in FIG. 6F is obtained in which the multi-stage recess 10G in the mask layer 120G is transferred.

[Step (b5)]
Next, oxygen plasma ashing is performed on the remaining mask layer 120G (40G) and the antireflection film 60G, and the mask layer 120G and the antireflection film 60G are peeled off. As a result, a stepped substrate 210G having a multistage structure pattern shown in FIG. 6G is obtained.

  As described above, the method for manufacturing a stepped substrate according to an embodiment of the present invention has been described. However, according to the present invention, it is possible to form a multistage structure pattern having various shapes on the substrate.

  The method for manufacturing a stepped substrate according to the present invention can be suitably applied to, for example, a dual damascene process for forming a multistage pattern.

  In addition, this invention relates also to the manufacturing method of an electronic device containing the manufacturing method of the level | step difference board | substrate of this invention mentioned above.

  The manufactured electronic device is suitably mounted on electrical and electronic equipment (home appliances, OA (Office automation) / media related equipment, optical equipment, communication equipment, and the like).

Hereinafter, the present invention will be described in detail with reference to examples. The present invention is not limited to the embodiments shown below, and the material and manufacturing method of the mask layer, and the manufacturing method, material, and etching conditions of the processing target layer and the etch stopper layer are within the scope not departing from the gist thereof. It is possible to implement by changing the above.
<Production of laminated substrate>
As the multilayer substrate, multilayer substrates X and Y described below were produced.
(1) Production of laminated substrate X [SiO ₂ / SiC / SiOC / Si substrate] A SiOC film having a film thickness of 200 nm was formed as a first processing target layer on the Si substrate by a plasma plasma CVD method.

  Subsequently, an SiC film having a thickness of 20 nm was formed as an etching stopper layer on the first processing target layer by a plasma CVD method.

Subsequently, an SiO ₂ film having a thickness of 200 nm was formed as a second processing target layer on the etching stopper layer by using a plasma CVD method.
(2) Production of Laminated Substrate Y [SiO ₂ / SiOC / Si Substrate] An SiOC film having a thickness of 200 nm was formed as a first processing target layer on the Si substrate by a plasma CVD method.

Subsequently, an SiO ₂ film having a thickness of 200 nm was formed as a second processing target layer on the first processing target layer by a plasma CVD method.
<Manufacture of mask layer>
The mask layer was produced by the photolithography method or the imprint method described below.
(1) Formation of mask layer by photolithography [Preparation of actinic ray-sensitive or radiation-sensitive resin composition]
The components shown in Table 1 below were dissolved in a total solid content of 3.8% by mass with the solvents shown in the same table, and each was filtered through a polyethylene filter having a pore size of 0.1 μm to obtain resin compositions (1) and (2 ) Was prepared.

[Acid-decomposable resin]
The acid-decomposable resins Pol-01 and Pol-22 are shown below together with the composition ratio of the repeating units, the weight average molecular weight (Mw: polystyrene conversion), and the dispersity (Mw / Mn).

The weight average molecular weight (Mw: polystyrene conversion) was determined from GPC (carrier: tetrahydrofuran (THF)). The composition ratio was measured by ¹³ C-NMR.

[Acid generator]
The acid generators in Table 1 are as follows.

[Basic compounds]
The basic compounds in Table 1 are as follows.

[Hydrophobic resin]
The hydrophobic resin (1b) in Table 1 is as follows. It is shown together with the composition ratio of the repeating unit, the weight average molecular weight (Mw: polystyrene conversion), and the dispersity (Mw / Mn).

The weight average molecular weight (Mw: polystyrene conversion) was determined from GPC (carrier: tetrahydrofuran (THF)). The composition ratio was measured by ¹³ C-NMR.

[Surfactant]
Surfactant W-1 in Table 1 is as follows.

W-1: MegaFuck F176 (Dainippon Ink Chemical Co., Ltd .; fluorine-based)
[solvent]
The solvents in Table 1 are as follows.

SL-1: Propylene glycol monomethyl ether acetate (PGMEA)
SL-4: Cyclohexanone SL-6: 4-Methyl-2-pentanol [Formation of first negative pattern]
(Formation of first film)
First, DUV42 (made by Brewer Science) for antireflection film was applied on the laminated substrate and baked at 205 ° C. for 60 seconds to form an antireflection film having a thickness of 64 nm.

  On top of that, the resin composition (1) shown in Table 1 above was applied, and first heating (PB1) was performed at 100 ° C. for 60 seconds to form a first film having a thickness of 200 nm.

(First negative pattern formation)
ArF excimer laser immersion scanner (manufactured by ASML; XT1700i, NA1.20, C-quad20, XY polarization, σout / in 0.981 / 0.895) is used for the first film and a mask (6% halftone hole pattern) Pattern exposure (first exposure) via a pattern pitch of 400 nm and a critical dimension (CD) of 90 nm). Ultra pure water was used as the immersion liquid. Next, the second heating (PEB1) was performed at 100 ° C. for 60 seconds. Next, organic solvent development was performed using butyl acetate to obtain a first negative pattern.
(Heating for forming the first negative pattern)
The first negative pattern obtained as described above was subjected to third heating (Post Bake 1) at 200 ° C. for 60 seconds.

[Formation of second negative pattern]
(Formation of second film)
On the substrate on which the first negative pattern is formed, the resin composition (2) shown in Table 1 is applied, and the fourth heating (PB2) is performed at 100 ° C. for 60 seconds, and the film thickness is 200 nm. A second film was formed.

(Second negative pattern formation)
ArF excimer laser immersion scanner (manufactured by ASML; XT1700i, NA0.75, Annular XY polarization, σout / in 0.97 / 0.740) is used for the second film, and a mask (6% halftone line and space pattern, Pattern exposure (first exposure) was performed via a pattern pitch: 400 nm and CD: 200 nm. Next, 5th heating (PEB2) was implemented over 60 second at 100 degreeC. Next, organic solvent development was performed using butyl acetate to obtain a second negative pattern.

The second negative pattern obtained as described above was subjected to sixth heating (Post Bake 2) at 100 ° C. for 60 seconds.
(2) Production of mask layer by imprint method [Production of multi-stage mold]
First, a quartz glass substrate for a photomask was prepared, and a chromium (Cr) film having a thickness of 50 nm was formed on the surface of the quartz glass substrate by sputtering. The Cr target used for sputtering has a purity of 99.995%. 100 sccm of Ar was introduced into the sputtering chamber, and the pressure in the sputtering chamber was 0.3 Pa. A Cr (Film) film was formed by applying plasma discharge from a DC (Direct Current) power source to the electrode under the 500 W target. Here, 1 sccm = 1.69 × 10 ⁻⁴ Pa · m ³ / s.
Next, positive resist FEP171 (manufactured by Fuji Film Electronics Material) for electron beam lithography was applied to the outermost surface of the quartz glass substrate on which the film formation by sputtering was performed, thereby forming a resist layer having a thickness of 250 nm.

Next, a resist pattern composed of a repetitive linear pattern with a pitch of 400 nm was formed on the quartz glass substrate on which the resist layer was formed by variable-beam electron beam lithography. Each linear pattern of the repeated linear patterns was designed to be parallel to the Y axis on the XY plane that is driven by the stage that holds the substrate during electron beam irradiation. The pattern formation region was a 10 cm × 10 cm square centered on the center of the substrate, the dose of electron beam irradiation was 10 μC / cm ^2, and post-exposure baking was performed for 10 minutes on a hot plate heated to 100 ° C. A TMAH (Tetramethylammonium hydroxide) aqueous solution (tetramethylammonium hydroxide aqueous solution) was used as the developer, and pure water was used as the rinse solution. Here, 1 μC / cm ² = 0.01 A · s / m ² .
Next, an etching process using plasma using a mixed gas of chlorine and oxygen was performed on a quartz glass substrate having a repetitive linear pattern formed of a resist film on the outermost surface, and the resist pattern was transferred to the Cr film. An ICP (Inductively Coupled Plasma) dry etching apparatus was applied to the etching process. After introducing 50 sccm of chlorine and 10 sccm of oxygen and setting the pressure in the plasma chamber to 1 Pa, ICP power 500 W and RIE power 50 W were applied to cause plasma discharge.

  Next, the quartz glass substrate on which the linear pattern is repeatedly formed on the Cr film is subjected to plasma etching using a mixed gas of ethane hexafluoride and helium, and the linear pattern is transferred to the quartz glass substrate. did. An ICP dry etching apparatus was applied to the etching process. Ethane hexafluoride and helium were introduced at 50 sccm at a time, the pressure in the plasma chamber was set to 1 Pa, and then ICP power 500 W and RIE power 200 W were applied to cause plasma discharge.

  Next, organic cleaning using NMP (N-methyl-2-pyrrolidone), MEA (monoethanolamine), etc., removal of the residual Cr film with a mixed aqueous solution of diammonium cerium nitrate and nitric acid, ammonia water and hydrogen peroxide Alkali cleaning using a mixed solution of water or the like was performed to obtain a quartz glass substrate on which the above linear pattern was formed.

  Next, a chromium (Cr) film having a thickness of 50 nm was formed by sputtering on the surface of the quartz glass substrate on which the above linear pattern was formed. The Cr target used for sputtering has a purity of 99.995%. 100 sccm of Ar was introduced into the sputtering chamber, and the pressure in the sputtering chamber was 0.3 Pa. A Cr power film was formed by applying a plasma discharge from a DC power source to the electrode under the 500 W target.

  A positive resist FEP171 (manufactured by Fuji Film Electronics Material) for electron beam lithography was applied to the outermost surface of the quartz glass substrate on which the film formation by sputtering was performed to form a resist layer having a film thickness of 250 nm.

Next, a resist pattern consisting of a cylindrical pattern with a diameter of 90 nm and a pitch of 400 nm is formed on the quartz glass substrate on which the resist layer is formed, on the convex portions of the repeating linear pattern with a pitch of 400 nm by electron beam lithography of variable shaping beam method. Formed. The dose of electron beam irradiation was 10 μC / cm ^2, and post-exposure baking was performed for 10 minutes on a hot plate heated to 100 ° C. A TMAH aqueous solution was used as a developing solution, and pure water was used as a rinsing solution.

  The quartz glass substrate on which the cylindrical resist pattern was formed was subjected to plasma etching using a mixed gas of chlorine and oxygen, and the resist pattern was transferred to the Cr film. An ICP dry etching apparatus was applied to the etching process. After introducing 50 sccm of chlorine and 10 sccm of oxygen and setting the pressure in the plasma chamber to 1 Pa, ICP power 500 W and RIE power 50 W were applied to cause plasma discharge.

  Next, the quartz glass substrate was subjected to etching using plasma using a mixed gas of hexafluoroethane and helium, and the cylindrical pattern was transferred to the quartz glass substrate. An ICP dry etching apparatus was applied to the etching process. Ethane hexafluoride and helium were introduced at 50 sccm at a time, the pressure in the plasma chamber was set to 1 Pa, and then ICP power 500 W and RIE power 200 W were applied to cause plasma discharge.

  Next, organic cleaning using NMP (N-methyl-2-pyrrolidone), MEA (monoethanolamine), etc., removal of the residual Cr film with a mixed aqueous solution of diammonium cerium nitrate and nitric acid, ammonia water and hydrogen peroxide Alkali cleaning using a mixed solution of water was performed to obtain a quartz glass substrate having a line and pillar structure (three-dimensional structure) in which holes and trenches were reversed.

  Next, OPTOOL HD-1100Z (manufactured by Daikin Industries) was applied as a release agent to the quartz glass substrate surface on which the three-dimensional structure was formed.

[Nanoimprint]
(Transfer substrate)
A Si substrate having a 200 mm square and a thickness of 7.25 mm was used as the lowermost substrate of the multilayer substrate. The surface of the laminated substrate was subjected to surface treatment with KBM-5103 (manufactured by Shin-Etsu Chemical Co., Ltd.), which is a silane coupling agent having excellent adhesion to the resist. Specifically, KBM-5103 was diluted to 1% by mass with PGMEA (propylene glycol monomethyl ether acetate), and this solution was applied to the surface of the laminated substrate by spin coating. Subsequently, the coated substrate was annealed on a hot plate at 150 ° C. for 5 minutes to bond the silane coupling agent to the substrate surface.

(Resist)
48% by mass of compound A represented by the following structural formula 1, 48% by mass of Aronix M220 (polypropylene glycol diacrylate; manufactured by Toagosei Co., Ltd.), 3% by mass of IRGACURE 379, a compound represented by the following structural formula 2 A resist containing 1% by mass of B was prepared.
Structural formula 1:

Structural formula 2:

(Resist application process)
A piezo inkjet printer, DMP-2838 manufactured by FUJIFILM Dimatix was used. DMC-11610, which is a dedicated head, was used as the inkjet head. The discharge conditions were adjusted in advance so that the droplet amount was 6 pl. The droplet arrangement pattern was a square lattice with a droplet interval of 400 μm, and the droplets were arranged on the entire transfer region according to this droplet arrangement pattern.

(Nanoimprint method)
The mold and the laminated substrate coated with resist were brought close to each other, and alignment was performed so that the alignment mark on the substrate and the alignment mark on the mold coincided from the back surface of the mold substrate.

  The space between the mold and the laminated substrate was replaced with He to form a 99% by volume or higher He gas atmosphere, and the pressure was reduced to 5 kPa. The mold was positioned with respect to the substrate under reduced pressure He conditions and brought into contact with the resist droplets. The time from when the pressure reaches 5 kPa until the mold contacts the resist is about 5 minutes.

After the contact, the pressure was applied for 5 seconds with a pressing pressure of 300 kPa, and the resist was cured by exposing to an irradiation amount of 300 mJ / cm 2 with ultraviolet light including a wavelength of 360 nm. The mold was peeled by moving the substrate or the mold in the direction opposite to the pressing in a state where the outer edge of the substrate and the mold was mechanically held or the back surface was sucked and held.
<Example 1: Production of stepped substrate 210H (sample number 101)>
The step substrate 210H shown in FIG. 7 (i) was manufactured by the following procedure.

[Fabrication of laminated substrate 110E]
A multilayer substrate 110H shown in FIG. 7A was fabricated by the method described in the fabrication of the multilayer substrate X [SiO ₂ / SiC / SiOC / Si substrate] described above as the multilayer substrate.

[Preparation of Mask Layer 120E]
An antireflection film (BARC) 60H and a mask layer 120H are formed on the stacked substrate 110H by the method described in the above-described mask layer manufacturing by the photolithography method, and the stack of the present invention shown in FIG. A body 100E was obtained.

[Etching process (H)]
Etching was performed according to the following procedure to obtain a stepped substrate 210H shown in FIG.

(1) First etching step (H1)
The antireflection film (BARC) 60H of the multilayer body 100H shown in FIG. 7B is etched using an Ar + O ₂ + CF ₄ mixed gas, and the first negative pattern 40H of the first negative pattern 40H in the mask layer 120H is subjected to etching. The shape of the recess 11H was transferred (FIG. 7C).

Etching H1 was performed with an ECR etching apparatus under the following conditions.
O ₂ : 10 sccm, CF ₄ : 10 sccm, Ar: 1000 sccm
Internal pressure: 4Pa
Plasma power 400W
Bias power 800W
Substrate temperature 50 ° C
(2) Second etching step (H2)
The second processing target layer 30H of the structure shown in FIG. 7C is etched using an Ar + O ₂ + C ₄ F ₆ mixed gas, so that the first negative pattern 40H in the mask layer 120H is a first one. The shape of the concave portion 11H was transferred (FIG. 7D).

Etching H2 was performed with an ECR etching apparatus under the following conditions.
O ₂ : 20 sccm, C ₄ F ₆ : 10 sccm, Ar: 500 sccm
Internal pressure 1Pa
Plasma power 500W
Bias power 700W
Substrate temperature 50 ° C
(3) Third etching step (H3)
The etching stopper layer 1H of the structure shown in FIG. 7D is etched using an SF ₆ + NH ₃ mixed gas, and the shape of the first recess 11H of the first negative pattern 40H in the mask layer 120H is formed. Was transferred (FIG. 7E).

Etching H3 was performed with an ECR etching apparatus under the following conditions.
SF ₆ : 35 sccm, NH ₃ : 25 sccm
Internal pressure 4Pa
Plasma power 600W
Bias power 200W
Substrate temperature 30 ° C
(4) Fourth etching step (H4)
The first processing target layer 20H of the structure shown in FIG. 7E is etched using an Ar + O ₂ + C ₄ F ₆ mixed gas, so that the first negative pattern 40H in the mask layer 120H is a first one. The shape of the concave portion 11H was transferred (FIG. 7F).

Etching H4 was performed with an ECR etching apparatus under the following conditions.
O ₂ : 20 sccm, C ₄ F ₆ : 10 sccm, Ar: 500 sccm
Internal pressure 4Pa
Plasma power 500W
Bias power 700W
Substrate temperature 50 ° C
(5) Fifth etching step (H5)
The first negative pattern 40H remaining in the mask layer of the structure shown in FIG. 7F and the antireflection film 60H are etched using an Ar + O ₂ + CF ₄ mixed gas, so that the first pattern in the mask layer 120H is obtained. The shape of the second concave portion 12H of the second negative pattern 50H was transferred (FIG. 7G).

Etching H5 was performed with an ECR etching apparatus under the following conditions.
O ₂ : 10 sccm, CF ₄ : 10 sccm, Ar: 1000 sccm
Internal pressure 4Pa
Plasma power 400W
Bias power 800W
Substrate temperature 50 ° C
(6) Sixth etching step (H6)
The second processing target layer 30H of the structure shown in FIG. 7G is etched using an Ar + O ₂ + C ₄ F ₆ mixed gas, so that the second negative pattern 50E in the mask layer 120H is second. The shape of the recess 12H was transferred (FIG. 7H).

Etching H6 was performed with an ECR etching apparatus under the following conditions.
O ₂ : 20 sccm, C ₄ F ₆ : 10 sccm, Ar: 500 sccm
Internal pressure 4Pa
Plasma power 500W
Bias power 700W
Substrate temperature 50 ° C
(7) Ashing Step The mask layer (40H) and the antireflection film 60H remaining in the structure shown in FIG. 7 (h) are subjected to an ashing process using O ₂ gas, thereby the mask layer (40H) and the antireflection film. The step substrate 210H shown in FIG. 7 (i) was obtained by peeling 60H.
The ashing process was performed with the ECR etching apparatus under the following conditions.
O2: 100 sccm, Ar: 100 sccm
Internal pressure 4Pa
Plasma power 1000W
Bias power 0W
Substrate temperature 50 ° C
<Example 2: Production of step substrate 210I (sample number 102)>
The step substrate 210I shown in FIG. 8H was manufactured by the following procedure.

[Fabrication of laminated substrate 110I]
A multilayer substrate 110I shown in FIG. 8A was fabricated by the method described in the fabrication of the multilayer substrate X [SiO ₂ / SiC / SiOC / Si substrate] described above as the multilayer substrate.

[Production of Mask Layer 120I]
An antireflection film (BARC) 60I and a mask layer 120I are formed on the multilayer substrate 110I by the method described in the above-described fabrication of the mask layer by the photolithography method, and the multilayer of the present invention shown in FIG. The body 100I was obtained.

[Etching process (I)]
Etching was performed according to the following procedure to obtain a stepped substrate 210F shown in FIG.

(1) First etching step (I1)
The antireflection film (BARC) 60I of the stacked body 100I of FIG. 8B is etched using an O ₂ + CF ₄ + Ar mixed gas, and the first negative pattern 40I of the first negative pattern 40I in the mask layer 120I is etched. The shape of the recess 11I was transferred (FIG. 8C).

  The etching conditions in the first etching step (I1) are the same as those in the first etching step (H1) in Example 1.

(2) Second etching step (I2)
The second processing target layer 30I of the structure shown in FIG. 8C is etched using an O ₂ + C ₄ F ₆ + Ar mixed gas, and the first negative pattern 40I of the mask layer 120I is subjected to etching. The shape of one recess 11I was transferred (FIG. 8D).

  The etching conditions in the second etching step (I2) are the same as those in the second etching step (H2) in the first embodiment.

(3) Third etching step (I3)
The etching stopper layer 1I of the structure shown in FIG. 8D is etched using an SF ₆ + NH ₃ mixed gas, and the shape of the first recess 11I of the first negative pattern 40I in the mask layer 120I is formed. Was transferred (FIG. 8E).

  The etching conditions in the third etching step (I3) are the same as those in the third etching step (H3) in Example 1.

(4) Fourth etching step (I4)
The remaining first negative pattern 40I and antireflection film 60I in the mask layer of the structure shown in FIG. 8E are etched using an O ₂ + CF ₄ + Ar mixed gas, and the mask layer 120I The shape of the second recess 12I of the second negative pattern 50I was transferred (FIG. 8 (f)).

  The etching conditions in the fourth etching step (I4) are the same as those in the fifth etching step (H5) in Example 1.

(5) Fifth etching step (I5)
The first processing target layer 20I and the second processing target layer 30I of the structure shown in FIG. 8F were simultaneously etched using an O ₂ + C ₄ F ₆ + Ar mixed gas. Thereby, the transfer of the shape of the first recess 11I in the mask layer 120I to the first processing target layer 20I and the transfer of the shape of the second recess 12I in the mask layer 120I to the second processing target layer 30I are performed. The process was performed in a lump to obtain the structure shown in FIG.

  The etching conditions in the fifth etching step (I5) are the same as those in the fourth etching step (H4) in Example 1.

(6) Ashing process The mask layer (40I) and the antireflection film 60I remaining in the structure shown in FIG. 8G are subjected to an ashing process using O ₂ gas, thereby the mask layer (40H) and the antireflection film. The step substrate 210I shown in FIG. 8G was obtained by peeling 60H.

The ashing process conditions are the same as the ashing process conditions in the first embodiment.
<Example 3: Production of stepped substrate 210J (sample number 103)>
The step substrate 210J shown in FIG. 9G was manufactured by the following procedure.

[Production of Laminated Substrate 110J]
A laminated substrate 110J shown in FIG. 9A was produced by the method described in the production of the laminated substrate X [SiO ₂ / SiC / SiOC / Si substrate] described above as the laminated substrate.

[Preparation of Mask Layer 120G]
An antireflection film (BARC) 60J and a mask layer 120J are formed on the multilayer substrate 110J by the method described in the above-described mask layer fabrication by the photolithography method, and the multilayer of the present invention shown in FIG. A body 100J was obtained.

[Etching process (J)]
Etching treatment was performed in the following procedure to obtain a stepped substrate 210J shown in FIG.

(1) First etching step (J1)
The antireflection film (BARC) 60J of the multilayer body 100J of FIG. 9B is etched using an O ₂ + CF ₄ + Ar mixed gas, and the first negative pattern 40J of the first negative pattern 40J in the mask layer 120J is applied. The shape of the recess 11J was transferred (FIG. 9C).

  The etching conditions in the first etching step (J1) are the same as those in the first etching step (H1) in Example 1.

(2) Second etching step (J2)
Etching was continuously performed on the second processing target layer 30J and the etching stopper layer 1J of the structure shown in FIG. 9C using an O ₂ + C ₄ F ₆ + Ar mixed gas. Thereby, the transfer of the first recess 11J in the mask layer 120J to the second processing target layer 30J and the transfer of the first recess 11J to the etching stopper layer 1J are collectively performed by one etching process. The structure shown in 9 (d) was obtained.

  The etching conditions in the second etching step (J2) are the same as those in the second etching step (H2) in Example 1.

(3) Third etching step (J3)
The remaining antireflection film 60J of the structure shown in FIG. 9D is etched using an O ₂ + CF ₄ + Ar mixed gas, and the second concave portion of the second negative pattern 50J in the mask layer 120J. The shape of 12J was transferred (FIG. 9 (e)).

  The etching conditions in the third etching step (J3) are the same as those in the fifth etching step (H5) in Example 1.

(4) Fourth etching step (J4)
The first processing target layer 20J and the second processing target layer 30J of the structure shown in FIG. 9E were simultaneously etched using an O ₂ + C ₄ F ₆ + Ar mixed gas. Thereby, the transfer of the shape of the first recess 11J in the mask layer 120J to the first processing target layer 20J and the transfer of the shape of the second recess 12J in the mask layer 120J to the second processing target layer 30J are performed. The process was performed in a lump to obtain the structure shown in FIG.

  The etching conditions in the fourth etching step (J4) are the same as those in the fourth etching step (H4) in Example 1.

(5) Ashing Step The mask layer (40J) and the antireflection film 60J remaining in the structure shown in FIG. 9 (f) are subjected to an ashing process using O ₂ gas, thereby the mask layer (40J) and the antireflection film. By peeling 60J, a step substrate 210J shown in FIG. 9G was obtained.

The ashing process conditions are the same as the ashing process conditions in the first embodiment.
<Example 4: Production of stepped substrate (sample number 104)>
A stepped substrate (sample number 104) was manufactured by the following procedure.

[Production of laminated substrate]
As the multilayer substrate, the multilayer substrate was fabricated by the method described in the fabrication of the multilayer substrate X [SiO ₂ / SiC / SiOC / Si substrate] described above.

[Production of mask layer]
A mask layer was produced on the laminated substrate by the method described in the production of the mask layer by the imprint method described above to obtain a laminate of the present invention.

[Etching process]
By the same method as the etching process (J) described in Example 3, the stacked body was subjected to an etching process, and then the ashing process described in Example 3 was performed to obtain a stepped substrate (sample number 104) of the present invention. .
<Comparative Example 1: Production of step substrate 210S (sample number 201)>
The step substrate 210S shown in FIG. 10G was manufactured by the following procedure.

[Production of Laminated Substrate 110S]
As the multilayer substrate, a multilayer substrate 110S shown in FIG. 10A was fabricated by the method described in the fabrication of the multilayer substrate Y [SiO ₂ / SiOC / Si substrate] described above.

[Production of Mask Layer 120S]
An antireflection film (BARC) 60S and a mask layer 120S are formed on the multilayer substrate 110S by the method described in the above-described mask layer fabrication by the photolithography method, and the multilayer body 100S illustrated in FIG. Obtained.

[Etching process (S)]
Etching was performed according to the following procedure to obtain a stepped substrate 210S shown in FIG.

(1) First etching step (S1)
The antireflection film (BARC) 60S of the stacked body 100S of FIG. 10B is etched using an O ₂ + CF ₄ + Ar mixed gas, and the first negative pattern 40S of the first negative pattern 40S in the mask layer 120S is processed. The shape of the recess 11S was transferred (FIG. 10C).

  The etching conditions in the first etching step (S1) are the same as those in the first etching step (H1) in the first embodiment.

(2) Second etching step (S2)
The first processing target layer 20S and the second processing target layer 30S of the structure shown in FIG. 10C are continuously subjected to an etching process using a mixed gas of O ₂ + C ₄ F ₆ + Ar, and a mask layer The shape of the first concave portion 11S of the first negative pattern 40S at 120S was transferred (FIG. 10D).

  The etching conditions in the second etching step (S2) are the same as those in the second etching step (H2) in the first embodiment.

(3) Third etching step (S3)
The first negative pattern 40S remaining in the mask layer of the structure shown in FIG. 10D and the antireflection film 60S are etched using an O ₂ + CF ₄ + Ar mixed gas, and the mask layer 120S The shape of the second recess 12S of the second negative pattern 50S was transferred (FIG. 10E).

  The etching conditions in the third etching step (S3) are the same as those in the fifth etching step (H5) in the first embodiment.

(4) Fourth etching step (S4)
The second processing target layer 30S of the structure shown in FIG. 10E is etched using an O ₂ + C ₄ F ₆ + Ar mixed gas, and the second negative pattern 50S in the mask layer 120S is subjected to etching. The shape of the second recess 12S was transferred (FIG. 10 (f)).

  The etching conditions in the fourth etching step (S4) are the same as those in the fourth etching step (H4) in Example 1.

(5) Ashing Step The mask layer (40S) and the antireflection film 60S remaining in the structure shown in FIG. 10 (f) are subjected to an ashing process using O ₂ gas, thereby the mask layer (40S) and the antireflection film. By separating 60S, a stepped substrate 210S shown in FIG. 10G was obtained.

  The ashing process conditions are the same as the ashing process conditions in the first embodiment.

<Evaluation>
[Pattern shape]
The cross section of the pattern was observed with a scanning electron microscope (S4800 manufactured by Hitachi, Ltd.), and the quality of the cross section was evaluated based on the following criteria. The results are shown in Table 2.

  A: A shape in which the concave portion has a multi-stage (two-stage) structure, the angle of the side wall portion of the concave portion is vertical, and there is no shoulder drop at the corner portion (see FIG. 11A).

B: Any of the shapes shown below.
A shape in which the recess is not a multi-stage (two-stage) structure (see FIGS. 11B and 11C).
A shape in which a shoulder drop occurs at the corner of the recess (see FIG. 11D).
A shape in which the angle of the side wall of the recess is not vertical (see FIG. 11E).

100A, 100B, 100C, 100E, 100F, 100G, 100H, 100I, 100J, 100S Laminated body 110A, 110B, 110C, 110D, 110E, 110F, 110G, 110H, 110I, 110J, 110S Laminated substrate 210D, 210E, 210F, 210G, 210H, 210I, 210J, 210S
Stepped substrates 120A, 120B, 120C, 120D, 120E, 120F, 120G, 120H, 120I, 120J, 120S Mask layers 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J First etching stopper layer 2A, 2B, 2C, 2D, 2E, 2F, 2G Second etching stopper layer 3, 3A, 3B, 3C, 3D, 3E, 3F, 3G, 3H, 3I, 3J, 3S Substrate 10A, 10B, 10C, 10D 10E, 10F, 10G, 10H, 10I, 10J, 10S Recesses 11A, 11B, 11C, 11D, 11E, 11F, 11G, 11H, 11I, 11J, 11S First recesses 12A, 12B, 12C, 12D, 12E, 12F, 12G, 12H, 12I, 12J, 12S Second recesses 20A, 20B, 20C, 20D, 20E, 20F, 20G, 20H, 20I, 20J, 20, 20S First processing target layer 30A, 30B, 30C, 30D, 30E, 30F, 30G, 30H, 30I, 30J, 30, 30S Second processing target layer 40A, 40B, 40D, 40D ′, 40E, 40F, 40G, 40H, 40I, 40J, 40S First negative pattern 50A, 50B, 50D, 50E, 50F, 50G, 50H, 50I, 50J, 50S
Second negative pattern 50D ′ Second film 60B, 60E, 60F, 60G, 60H, 60I, 60J, 60S Antireflection film 70C Residual film layer

Claims (17)

A method of manufacturing a stepped substrate having a pattern with a multi-stage recess having a width that decreases stepwise in the depth direction,
(A) A multi-stage structure in which a width is gradually reduced in a depth direction on a laminated substrate in which a substrate, a first processing target layer, an etching stopper layer, and a second processing target layer are stacked in this order. A mask pattern comprising at least a first recess having a lowest width and a second recess being an upper stage of the first recess. A step of forming a mask layer having, and (b) a step of etching the laminated substrate using the mask layer as a mask to transfer the shape of the mask pattern,
A method for manufacturing a stepped substrate including: The step (a) of forming a mask layer having the mask pattern comprises:
(I) forming a first negative pattern having a first recess on the laminated substrate; and
(Ii) forming a second negative pattern having a second recess on the first negative pattern;
Including
The step (i)
(I-1) forming a first film on the laminated substrate using the actinic ray-sensitive or radiation-sensitive resin composition (1);
(I-2) a step of exposing the first film, and (i-3) a step of developing the exposed first film using a first developer,
Including
The step (ii)
(Ii-1) forming a second film on the first negative pattern using the actinic ray-sensitive or radiation-sensitive resin composition (2);
(Ii-2) exposing the second film, and
(Ii-3) developing the exposed second film using a second developer,
The manufacturing method of the level | step difference board | substrate of Claim 1 containing this.   The actinic ray-sensitive or radiation-sensitive resin composition (1) is a composition containing a resin whose polarity is increased by the action of an acid and whose solubility in a developer containing an organic solvent is reduced. The manufacturing method of the level | step difference board | substrate of description.   The manufacturing method of the level | step difference board | substrate of Claim 2 or 3 whose 1st developing solution is a developing solution containing the organic solvent.   The actinic ray-sensitive or radiation-sensitive resin composition (2) is a composition containing a resin whose polarity increases by the action of an acid and whose solubility in a developer containing an organic solvent decreases. 5. A method for manufacturing a stepped substrate according to any one of 4 above.   The manufacturing method of the level | step difference board | substrate of any one of Claims 2-5 whose 2nd developing solution is a developing solution containing the organic solvent.   The method for manufacturing a stepped substrate according to any one of claims 2 to 6, further comprising a heating step between the step (i) and the step (ii).   The actinic ray-sensitive or radiation-sensitive resin composition (1) and the actinic ray-sensitive or radiation-sensitive resin composition (2) are different compositions according to any one of claims 2 to 7. A method for manufacturing a stepped substrate.   The actinic ray-sensitive or radiation-sensitive resin composition (1) and the actinic ray-sensitive or radiation-sensitive resin composition (2) are the same composition, according to any one of claims 2 to 7. Manufacturing method for stepped substrate.   The step (a) of forming the mask layer having the mask pattern is performed by an imprint method using a mold having a pattern having a multi-stage projecting portion whose width gradually decreases from the bottom toward the top. The manufacturing method of the level | step difference board | substrate of Claim 1 including forming a mask pattern. An etching process step (b) for transferring the shape of the mask pattern;
(B1) a step of transferring the shape of the first recess to the second processing target layer by the first etching;
(B2) transferring the shape of the first recess to the etching stopper layer by second etching;
(B3) transferring the shape of the first recess to the first processing target layer by the third etching; and (b4) transferring the shape of the second recess to the second processing target layer by the fourth etching. The manufacturing method of the level | step difference board | substrate of any one of Claims 1-10 including the process to do.   The manufacturing method of the level | step difference board | substrate of Claim 11 which performs a process (b3) and a process (b4) simultaneously.   The method for manufacturing a stepped substrate according to claim 11 or 12, wherein the step (b1) and the step (b2) are collectively performed under the same etching conditions.   The method further includes, before the step (b1), transferring the shape of the first recess to the layer by etching when the layer is interposed between the first recess in the mask layer and the laminated substrate. Item 14. The method for manufacturing a stepped substrate according to any one of Items 11 to 13.   The method for manufacturing a stepped substrate according to any one of claims 1 to 14, wherein the stepped substrate having a pattern having a multi-stage recessed portion is a stepped substrate having a dual damascene structure.   The manufacturing method of an electronic device containing the manufacturing method of the level | step difference board of any one of Claims 1-15.   A multi-stage recess having a width that decreases stepwise in the depth direction is provided on a stacked substrate in which the substrate, the first processing target layer, the etching stopper layer, and the second processing target layer are stacked in this order. A laminate comprising a mask layer having a mask pattern.