TWI879191B - Semiconductor device manufacturing method and semiconductor manufacturing device - Google Patents

Abstract

A method for manufacturing a semiconductor device and a semiconductor manufacturing device are provided, wherein a self-assembled monomolecular film having excellent density and protective properties is formed as a protective layer, thereby enabling good selective etching of an etched layer. The method for manufacturing a semiconductor device of the present invention includes processing a substrate, wherein the substrate is a layer stack formed by alternately stacking a protective layer and an etched layer; the method for manufacturing a semiconductor device includes the following steps: selectively forming a SAM on at least the surface of the protected layer; and using the SAM as a protective layer and selectively etching the etched layer; the steps for forming the SAM include: a first contact step, wherein a first processing solution containing SAM molecules is brought into contact with the surface of the protected layer, and SAM molecules are chemically adsorbed; a removal process is to remove non-chemically adsorbed SAM molecules from the surface of the protected layer; a surface modification process is to modify the surface of the protected layer after the removal process in the area where no SAM molecules exist to become an area capable of chemically adsorbing SAM molecules; and a second contact process is to make a second treatment liquid containing SAM molecules and of the same type or different type as the first treatment liquid contact with the surface-modified area to chemically adsorb the SAM molecules.

Description

Semiconductor device manufacturing method and semiconductor manufacturing device

The present invention relates to a method for manufacturing a semiconductor device and a semiconductor manufacturing device, wherein a self-assembled monolayer having excellent density and protective performance is formed as a protective layer, thereby enabling good selective etching of an etched layer.

As a device capable of storing data in a non-volatile manner, a NAND (NOT-AND) type flash memory is known. As a NAND type flash memory, for example, there is a three-dimensional NAND type flash memory, which is constructed by vertically stacking memory cells and arranging them on a substrate.

Furthermore, in a three-dimensional NAND structure such as a three-dimensional NAND type flash memory, in the etching process, it is required to form not only a recess having a wider opening but also a recess having a narrow opening and a deep shape in the film thickness direction.

As such etching treatment, for example, there is the following treatment: in the case of a substrate having a silicon nitride (SiN) film and a silicon oxide (SiO ₂ ) film provided in the surface, the silicon nitride film is etched by a wet etching method using phosphoric acid (H ₃ PO ₄ ) as a processing liquid (etching liquid) (Patent Document 1). However, when the concentration of silicon (Si) in the processing liquid is high, the following problem occurs: due to the high etching speed, the replacement speed of the processing liquid in the three-dimensional NAND structure cannot keep up, and the etched silicon component will precipitate and adhere to the surface of the silicon oxide film. In addition, when the silicon concentration in the processing solution is low, the following problem also occurs: the selectivity of etching is reduced, resulting in etching of the silicon oxide film. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Application No. 2021-027125.

[The problem that the invention wants to solve]

The present invention is developed in view of the above-mentioned problems, and aims to provide a method for manufacturing a semiconductor device and a semiconductor manufacturing device, which uses a self-assembled monolayer film with excellent density and protective performance as a protective layer, thereby enabling good selective etching of the etched layer. [Means for solving the problem]

In order to solve the above-mentioned problem, the manufacturing method of the semiconductor device of the present invention includes processing a substrate having a layer stack disposed on the surface; the layer stack includes a structure formed by alternately stacking a protected layer as a protection object to be etched and an etched layer as an object to be etched; the manufacturing method of the semiconductor device includes the following steps: selectively forming a self-assembled monomolecular film on at least the surface of the protected layer; and using the self-assembled monomolecular film as a protective layer and selectively etching the etched layer; the steps for forming the self-assembled monomolecular film include: a first contact step, which is to make the layer containing the self-assembled monomolecular film capable of being etched. A first treatment liquid containing molecules capable of forming the aforementioned self-assembled monolayer is brought into contact with the surface of the aforementioned protected layer to chemically adsorb the aforementioned molecules; a removal step is performed to remove the aforementioned molecules that have not been chemically adsorbed from the surface of the aforementioned protected layer; a surface modification step is performed to modify the surface of the aforementioned protected layer after the aforementioned removal step in areas where the aforementioned molecules do not exist into areas capable of chemically adsorbing the aforementioned molecules; and a second contact step is performed to bring a second treatment liquid containing the aforementioned molecules and of the same type or a different type as the aforementioned first treatment liquid into contact with the aforementioned surface-modified area to chemically adsorb the aforementioned molecules.

In the method for manufacturing a semiconductor device described above, when etching the etched layer, a self-assembled monolayer (hereinafter referred to as "SAM") is formed on at least the surface of the protected layer for protection, thereby improving the selective etching performance of the etched layer. Moreover, in the structure described above, the following steps are performed in sequence in the SAM formation process. That is, first, the molecules capable of forming SAM (hereinafter referred to as "SAM molecules") are chemically adsorbed on the surface of the substrate through a first contact process, and then the non-chemically adsorbed SAM molecules are removed through a removal process. In this way, the surface modification of the area where the SAM molecules cannot be chemically adsorbed is suppressed. Furthermore, the surface modification process is used to modify the area capable of chemically adsorbing SAM molecules, and then the second contact process is used to chemically adsorb the SAM molecules on the area where the surface modification is applied.

With this structure, the area where the SAM molecules cannot be chemically adsorbed by the first contact process can be subjected to surface modification in a manner that allows the SAM molecules to be chemically adsorbed again, thereby reducing the need for the SAM molecules to contact the surface of the substrate for a long time in order to form a dense SAM as in the previous method. As a result, the occurrence of film defects can be suppressed, and a SAM with excellent density and protective performance can be efficiently formed in a short time. Moreover, the SAM with excellent density and protective performance is formed as a protective layer on at least the surface of the protected layer, thereby enabling good selective etching of the protected layer.

In the structure described above, the following step is further included before the process for forming the aforementioned self-assembled monolayer: etching the aforementioned etched layer in the film thickness direction until it reaches a predetermined depth; the process for forming the aforementioned self-assembled monolayer can be the following process: forming the aforementioned self-assembled monolayer in the aforementioned protective layer and also on the side surface of the aforementioned etched layer exposed by etching.

In the case where the etched layer is etched to a predetermined depth in the film thickness direction, the side surface of the protected layer is also exposed to the extent of the etched layer. However, in the configuration described above, even in this case, SAM is formed not only on the surface of the protected layer but also on the exposed side surface, thereby enabling the selective etching of the etched layer to be performed well while protecting the protected layer.

In the above-described configuration, it is preferred that the second contacting step is a step of chemically adsorbing the molecules on the area that has been surface-modified by the surface modification step, and performing a densification treatment on the self-assembled monolayer formed by the first contacting step.

According to the structure described above, after forming SAM in the first contact process, the SAM molecules that are not chemically adsorbed on the surface of the substrate are removed by a removal process, and then the surface modification is applied in a manner that the SAM molecules can be chemically adsorbed on the area where no SAM molecules exist. Thereafter, in the second contact process, the second processing liquid containing SAM molecules is contacted to the area where no SAM molecules exist. Here, in the SAM formed by the first contact process, there will be the following situation: the SAM molecules will be partially unable to be chemically adsorbed on the surface of the substrate, etc., thereby causing film defects. However, in the structure described above, after forming SAM by the first contact process, the SAM molecules that are not chemically adsorbed are removed from the area where the film defects occur and the surface modification is applied, and the SAM molecules are chemically adsorbed on the area where the film defects occur, thereby enhancing or even improving the compactness of the SAM. Thus, unlike the conventional SAM film forming method, it is not necessary to allow the SAM molecules to contact the surface of the substrate for a long time, so that a SAM with excellent density and protection performance can be efficiently formed in a short time. Moreover, the SAM with excellent density and protection performance is formed as a protective layer on at least the surface of the protected layer, thereby enabling good selective etching of the protected layer.

Furthermore, in the structure described above, it is preferred that the aforementioned protected layer is composed of silicon dioxide; the aforementioned etched layer is composed of silicon nitride; the aforementioned molecules have functional groups capable of forming siloxane bonds with hydroxyl groups; the surface modification in the aforementioned surface modification step is to generate hydroxyl groups in areas where the aforementioned molecules do not exist; and the chemical adsorption of the aforementioned molecules in the aforementioned first contact step and the aforementioned second contact step is to bond the aforementioned molecules to the aforementioned surface via siloxane bonds with the hydroxyl groups on the surface of the aforementioned protected layer.

According to the structure described above, the surface of the protected layer is modified by forming hydroxyl groups at least on the surface of the protected layer composed of silicon dioxide, thereby enabling molecules having functional groups capable of forming siloxane bonds with hydroxyl groups to be chemically adsorbed on the surface of the protected layer via the siloxane bonds.

In the structure described above, the surface modification step may be the following step: a surface modification liquid is brought into contact with an area on the surface of the protected layer after the removal step where the aforementioned molecules are not present; and a solution for generating hydroxyl groups on the surface of the protected layer composed of the aforementioned silicon dioxide is used as the surface modification liquid.

In addition, in the structure described above, the surface modification process may be at least one of the following processes: a process for bringing ozone gas into contact with areas on the surface of the protected layer where the aforementioned molecules do not exist; a process for irradiating ultraviolet rays to areas on the surface of the protected layer where the aforementioned molecules do not exist; and a process for bringing a gas containing water into contact with areas on the surface of the protected layer where the aforementioned molecules do not exist.

Furthermore, in the above-described structure, it is preferred that the aforementioned molecule comprises octadecyltrichlorosilane (C ₁₈ H ₃₇ SiCl ₃ ).

In order to solve the above-mentioned problem, the semiconductor manufacturing device of the present invention is used to process a substrate having a layer stack disposed on the surface; the layer stack is a structure formed by alternately stacking a protected layer as a protection object to be etched and an etched layer as an object to be etched; the semiconductor manufacturing device is equipped with: a substrate processing unit, which selectively forms a self-assembled monomolecular film on at least the surface of the protected layer; and an etching processing unit, which uses the self-assembled monomolecular film as a protective layer and selectively etches and removes the etched layer; the substrate processing unit The invention comprises: a supply section for supplying a treatment liquid containing molecules capable of forming the self-assembled monolayer to the surface of the substrate; a removal liquid supply section for supplying the removal liquid to the surface after the treatment liquid is supplied, thereby removing the molecules that are not chemically adsorbed; and a surface modification section for modifying the surface after the molecules are removed by the removal liquid supply section and the area where the molecules are not present into an area capable of chemically adsorbing the molecules; the supply section also supplies the treatment liquid to the surface of the substrate after the surface modification is performed by the surface modification section.

The semiconductor manufacturing device of the structure described above at least comprises: a substrate processing unit, which selectively forms a SAM on a protected layer; and an etching processing unit, which selectively etches and removes the etched layer; before etching the etched layer in the etching processing unit, a SAM is formed in advance on at least the surface of the protected layer in the substrate processing unit to protect it, thereby enabling excellent selective etching of the etched layer. Moreover, in the structure described above, the supply unit supplies a processing liquid containing SAM molecules to the surface of the substrate, thereby enabling the SAM molecules to be chemically adsorbed to the area where the SAM molecules can be chemically adsorbed. In addition, the removal liquid supply unit removes the SAM molecules not chemically adsorbed on the surface of the substrate, thereby fully exposing the area where the SAM molecules are not chemically adsorbed. Furthermore, the surface modification unit performs surface modification on the area where the SAM molecules are not chemically adsorbed, thereby chemically adsorbing the SAM molecules to the area.

With this configuration, the supply unit supplies the treatment liquid again to the area that has been subjected to surface modification, thereby enabling the SAM molecules to be chemically adsorbed to the area, thereby reducing the situation where the SAM molecules are in contact with the surface of the substrate for a long time in order to form a dense SAM compared to the previous semiconductor manufacturing device. As a result, the occurrence of film defects can be suppressed, and a SAM with excellent density and protective performance can be efficiently formed in a short time. Moreover, the SAM with excellent density and protective performance is formed as a protective layer on at least the surface of the protected layer, thereby enabling the etched layer to be selectively etched well.

In the structure described above, the etching processing unit may also etch the etched layer in the film thickness direction to a predetermined depth before forming the self-assembled monolayer; and the substrate processing unit may form the self-assembled monolayer in the protective layer and on the side surface of the etched layer exposed by etching.

In the case where the etching processing unit etches the etched layer in advance to a predetermined depth in the film thickness direction, the side surface of the protected layer is also exposed by etching the etched layer. However, in the structure described above, even in this case, the substrate processing unit forms SAM not only on the surface of the protected layer but also on the exposed side surface, thereby being able to perform selective etching of the protected layer well.

In the structure described above, it is preferred that the aforementioned protected layer is composed of silicon dioxide; the aforementioned etched layer is composed of silicon nitride; the aforementioned molecules have functional groups capable of siloxane bonding with hydroxyl groups; the aforementioned surface modification section is a surface modification liquid supply section for supplying surface modification liquid to areas where the aforementioned molecules are not present; and a solution for generating hydroxyl groups on the surface of the aforementioned protected layer is used as the aforementioned surface modification liquid.

In addition, in the structure described above, the aforementioned protected layer is composed of silicon dioxide; the aforementioned etched layer is composed of silicon nitride; the aforementioned molecule has a functional group capable of siloxane bonding with a hydroxyl group; the aforementioned surface modification unit is at least one of an ozone gas supply unit, an ultraviolet irradiation unit, and a gas supply unit, the aforementioned ozone gas supply unit supplies ozone gas to the area on the surface of the aforementioned protected layer where the aforementioned molecule does not exist, the aforementioned ultraviolet irradiation unit irradiates ultraviolet rays to the area on the surface of the aforementioned protected layer where the aforementioned molecule does not exist, and the aforementioned gas supply unit supplies gas containing water to the area on the surface of the aforementioned protected layer where the aforementioned molecule does not exist. [Effect of the invention]

According to the present invention, a self-assembled monolayer with excellent density and protection performance is formed as a protective layer on at least the surface of the protected layer, thereby preventing the etched layer from being etched and preventing the etched components from being precipitated onto the surface of the etched layer. As a result, according to the present invention, a method for manufacturing a semiconductor device and a semiconductor manufacturing device can be provided, which can perform selective etching of the etched layer well and can well manufacture semiconductor devices such as three-dimensional NAND structures.

[First embodiment] The following describes a method for manufacturing a semiconductor device and a semiconductor manufacturing device according to the first embodiment of the present invention.

[Manufacturing method of semiconductor device] First, the manufacturing method of the semiconductor device of the present embodiment is described below with reference to the drawings. The manufacturing method of the semiconductor device of the present embodiment provides the following technology: when a three-dimensional structure such as a three-dimensional NAND structure is formed on the surface of a substrate, good selective etching can be performed.

In the following, in the manufacturing method of the semiconductor device of the present embodiment, a part of the process for forming a three-dimensional NAND structure on a substrate W composed of silicon or the like is described as an example. More specifically, the case of processing a substrate W provided with a stack 3 of a three-dimensional structure as shown in FIG1A is taken as an example. FIG1A is a schematic cross-sectional view of the stack 3 provided on the substrate W, and shows the state before the etching process; FIG1B shows the state after the etching process.

The stack 3 includes a structure in which SiO2 _layers 1 and SiN layers 2 are alternately stacked on a substrate W as shown in FIG. 2A; the SiO2 layer ₁ functions as an interlayer insulating layer, and the SiN layer 2 functions as a sacrificial layer. In addition, a plurality of memory trenches 4 are provided in the stack 3, and the plurality of memory trenches 4 extend in a direction perpendicular to the surface of the substrate W so as to penetrate the stack 3. In addition, FIG. 2A is a partial enlarged view of the portion surrounded by A in the stack 3 of FIG. 1A.

The method for manufacturing a semiconductor device of the present embodiment includes at least a self-assembled monolayer (hereinafter referred to as "SAM") forming step (hereinafter referred to as "SAM forming step") S1 and an etching step S2 as shown in FIG3, and can selectively etch the SiN layer 2 through the memory trench 4, thereby forming a concave portion on the side surface of the memory trench 4 in the stack 3. FIG3 is a flow chart showing an example of the overall flow of the method for manufacturing a semiconductor device of the present embodiment.

[SAM formation step S1] The SAM formation step S1 is a step in which a SAM serving as a protective layer is selectively formed on the surface of the _SiO2 layer 1 which is the protected layer. As shown in FIG3 , the SAM formation step S1 includes at least a first contact step S101, a removal step S102, a surface modification step S103, a densification step (second contact step) S104, and a rinse step S105.

[1. First contact process S101] The first contact process S101 is a process in which a first processing liquid containing a material capable of forming a SAM (hereinafter referred to as "SAM forming material") is brought into contact with the surface of the substrate W to form a SAM.

The method for bringing the first processing liquid into contact with the substrate W is not particularly limited, and examples thereof include: a method for applying the first processing liquid to the surface of the substrate W; a method for spraying the first processing liquid onto the surface of the substrate W; a method for immersing the substrate W in the first processing liquid.

As a method for applying the first processing liquid to the surface of the substrate W, for example, the following method can be cited: the first processing liquid is supplied to the center of the surface of the substrate W while the substrate W is rotated at a fixed speed with the center of the substrate W as an axis. Thus, the first processing liquid supplied to the surface of the substrate W flows from the vicinity of the center of the surface of the substrate W toward the peripheral portion of the substrate W by the centrifugal force generated by the rotation of the substrate W, and diffuses to the entire surface of the substrate W. As a result, the entire surface of the substrate W is covered with the first processing liquid, thereby forming a liquid film of the first processing liquid.

The first treatment liquid at least contains a SAM forming material. In addition, the SAM forming material in the first treatment liquid can be dissolved in a solvent or dispersed in a solvent. The SAM forming material is not particularly limited, and examples thereof include organic silane compounds such as octadecyltrichlorosilane. Octadecyltrichlorosilane is a compound having a trichlorosilyl group as a functional group capable of forming a siloxane bond with a hydroxyl group. In addition, the solvent is not particularly limited, and examples thereof include ether solvents, aromatic hydrocarbon solvents, aliphatic hydrocarbon solvents, fluorine solvents, etc. The ether solvent is not particularly limited, and examples thereof include tetrahydrofuran (THF; tetrahydrofuran), etc. The aromatic hydrocarbon solvent is not particularly limited, and examples thereof include toluene. The aliphatic hydrocarbon solvent is not particularly limited, and examples thereof include decane. The fluorine-based solvent is not particularly limited, and examples thereof include 1,3-bis(trifluoromethyl)benzene. These solvents may be used alone or in combination of two or more. From the perspective of being able to dissolve octadecyltrichlorosilane in the exemplified solvents, an aliphatic hydrocarbon solvent is preferred, and decane is more preferred.

The content of the SAM forming material relative to the total mass of the first treatment solution is preferably in the range of 0.005 mass % to 100 mass %, more preferably in the range of 0.05 mass % to 50 mass %, and even more preferably in the range of 1 mass % to 10 mass %.

In addition, the first treatment liquid may contain a known additive within the range that does not hinder the effect of the present invention. The additive is not particularly limited, and examples thereof include stabilizers and surfactants.

The conditions for bringing the first treatment liquid into contact with the substrate W are not particularly limited. However, compared with the case of forming a SAM film by a conventional method, the first contact process S101 of the present embodiment can shorten the contact time of the first treatment liquid. Specifically, the time required for the first contact process S101 (the immersion time in the case of immersing the substrate W in the first treatment liquid) can be appropriately set within the following time range: within the range of 1 minute to 1440 minutes, preferably within the range of 1 minute to 60 minutes, and more preferably within the range of 1 minute to 10 minutes, depending on the type and concentration of the SAM forming material, the type of solvent, etc.

Next, the formation process of SAM is described in more detail by taking the case where the SAM forming material is octadecyltrichlorosilane as an example.

As shown in FIG4A, when the first processing liquid is supplied to the surface of the substrate W, molecules capable of forming SAM (octadecyltrichlorosilane, hereinafter referred to as "SAM molecules") 5 are dispersed or dissolved in the first processing liquid supplied initially. FIG4A is a schematic diagram showing the first processing liquid being supplied to the surface of the _SiO2 layer 1.

Next, as shown in FIG. 4B , when a hydroxyl group (OH group) 6 exists on the surface of the SiO ₂ layer 1, the SAM molecule 5 uses the hydroxyl group 6 as a reaction site and is chemically adsorbed on the surface of the SiO ₂ layer 1. More specifically, the trichlorosilyl group of the SAM molecule 5 reacts with the hydroxyl group 6 to form a siloxane bond, so that the SAM molecule 5 is chemically adsorbed on the surface of the SiO ₂ layer 1. In addition, in the case where water molecules 7 exist on the surface of the SiO ₂ layer 1 and/or in the first treatment solution, the SAM molecules 5 are condensed around the water molecules 7. In particular, the SAM molecules 5 form reverse micelles 8 with the water molecules 7 present in the first treatment solution, and the reverse micelles 8 incorporate the water molecules 7 inside. In addition, FIG. 4B is a schematic diagram showing the appearance of the SAM molecules 5 being chemically adsorbed on the surface of the SiO ₂ layer 1.

Next, when the SAM molecules 5 are chemically adsorbed at a high density on the surface of the SiO ₂ layer 1, an island structure of the SAM molecules 5 is presented on the surface of the SiO ₂ layer 1. Furthermore, in these islands of SAM molecules 5, the SAM molecules 5 grow (expand) by self-assembly due to the hydrophobic interaction and/or electrostatic interaction between each other, and finally form SAM9 (refer to FIG. 4C). However, film defects C occur in the following parts of SAM9, etc.: the area where the inverse micelles 8 are attached to the surface of the SiO ₂ layer 1; the boundary between the adjacent islands where the SAM molecules 5 have not entered; the area where the SAM molecules 5 are attached to the surface of the SiO ₂ layer 1 instead of being chemically adsorbed. In addition, FIG. 4C is a schematic diagram showing how the SAM molecules 5 self-assemble on the surface of the SiO ₂ layer 1 to form SAM9.

[2. Removal process S102] The removal process S102 is a process for removing the first treatment solution remaining on the surface of the SiO2 layer ₁ after the first contact process S101. In this way, the remaining SAM molecules 5 that do not contribute to the formation of SAM ₉ are removed from the surface of the _SiO2 layer 1. More specifically, the SAM molecules 5 (including the reverse micelles 8) that are not chemically adsorbed on the surface of the SiO2 layer 1 are removed from the surface of the _SiO2 layer 1.

The method for removing the first processing liquid from the surface of the _SiO2 layer 1 is not particularly limited, and examples thereof include: a method for applying the removal liquid to the surface of the substrate W; a method for spraying the removal liquid onto the surface of the substrate W; a method for immersing the substrate W in the removal liquid.

As a method for applying the removal liquid to the surface of the substrate W, for example, the following method can be cited: while the substrate W is rotated at a fixed speed with the center of the substrate W as an axis, the removal liquid is supplied to the center of the surface of the substrate W. Thus, the removal liquid supplied to the surface of the substrate W flows from the vicinity of the center of the surface of the substrate W toward the periphery of the substrate W by the centrifugal force generated by the rotation of the substrate W, and diffuses to the entire surface of the substrate W. As a result, the first processing liquid on the surface of the substrate W is replaced by the removal liquid, and the entire surface of the substrate W is covered with the removal liquid to form a liquid film of the removal liquid.

In the case where the SAM forming material is octadecyltrichlorosilane, the surface of the SiO2 layer ₁ after the removal step S102 is as shown in FIG5A. As shown in FIG5A, the SAM molecules 5 and the inverse micelles 8 that do not contribute to the film formation of the SAM 9 are removed from the surface of the SiO2 layer ₁ of the substrate W. FIG5A is a schematic diagram showing the appearance of the surface of the _SiO2 layer 1 after the remaining SAM molecules 5 and the inverse micelles 8 are removed.

As a removal liquid, an organic solvent is preferred; the organic solvent dissolves the SAM forming material and has a low solubility in water, thereby suppressing the water content. When the removal liquid is capable of dissolving the SAM forming material, the remaining SAM molecules 5 and the reverse micelles 8 that do not contribute to the formation of SAM ₉ can be well removed from the surface of the SiO 2 layer 1. The removal liquid is preferably one that has a solubility in water of 0.033% (330 ppm) or less at 25°C. More specifically, the removal liquid can include, for example, toluene, decane, 1,3-bis(trifluoromethyl)benzene, etc. These solvents can be used alone or in combination of two or more.

[3. Surface modification step S103] The surface modification step S103 is the following step: modifying the surface of the area where the film defect C occurs in the surface of the _SiO2 layer 1 into an area capable of chemical adsorption of the SAM molecules 5, that is, modifying the surface of the area where the SAM 9 is not formed into an area capable of chemical adsorption of the SAM molecules 5. Here, the "surface modification into an area capable of chemical adsorption" in this specification means that the surface modification is performed in a manner that a hydroxyl group (OH group) is generated on the surface of the SiO2 layer _1. Alternatively, the so-called "surface modification" in this embodiment can also be referred to as a treatment for generating a silanol group (Si-OH group) in the SiO2 layer ₁ .

When the surface of the _SiO2 layer 1 is modified, as shown in Fig. 5B, hydroxyl groups 6 are generated in the film defects C of the SAM 9 in a manner that allows chemical adsorption of SAM molecules 5. Fig. 5B is a schematic diagram showing how the surface modification is applied to the area where no SAM molecules 5 exist and hydroxyl groups 6 are generated.

In the present embodiment, the surface modification of the surface of the SiO2 layer ₁ is performed by a wet method. More specifically, the surface modification liquid is brought into contact with the surface of the substrate W after the removal step S102. The method for bringing the surface modification liquid into contact with the surface of the substrate W is not particularly limited, and examples thereof include the following methods: a method for applying the surface modification liquid to the surface of the substrate W; a method for spraying the surface modification liquid onto the surface of the substrate W; a method for immersing the substrate W in the surface modification liquid.

Furthermore, as a method for applying the surface modification liquid to the surface of the substrate W, for example, the following method can be cited: the surface modification liquid is supplied to the center of the surface of the substrate W while the substrate W is rotated at a constant speed with the center of the substrate W as an axis. Thus, the surface modification liquid supplied to the surface of the substrate W flows from the vicinity of the center of the surface of the substrate W toward the peripheral portion of the substrate W by the centrifugal force generated by the rotation of the substrate W, and diffuses to the entire surface of the substrate W. As a result, the entire surface of the substrate W is covered with the surface modification liquid, thereby forming a liquid film of the surface modification liquid.

Examples of the surface modification liquid include SC-1 (standard clean-1, i.e., ammonia-hydrogen peroxide mixture) (in terms of volume ratio, ammonia (NH ₃ concentration of 28%): hydrogen peroxide (H ₂ O ₂ concentration of 30%): DIW (deionized water) = 1:4:20), ammonium hydroxide (NH ₄ OH), hydrogen peroxide (H ₂ O ₂ ), ammonium fluoride (NH ₄ F), diluted sulfuric acid/hydrogen peroxide mixture (SPM (sulfuric acid/hydrogen peroxide mixture)), diluted nitric acid, a mixed solution of hydrofluoric acid and ammonia, ozone water, ozone deionized water, water, etc. From the perspective of being able to well introduce hydroxyl groups into the surface of the _SiO2 layer 1, SC-1 is the most preferred of these surface modification solutions.

In addition, in the case where the surface modification step S103 is performed by a wet method, it is preferred to sequentially perform a cleaning step and a drying step for removing the surface modification liquid immediately after the surface modification step S103 is completed. The cleaning method in the cleaning step is not particularly limited, and examples thereof include the following methods: a method for supplying a cleaning liquid to the surface of the substrate W; a method for immersing the substrate W in the cleaning liquid. In addition, examples of the cleaning liquid include toluene, decane, 1,3-bis(trifluoromethyl)benzene, etc. These solvents can be used alone or in combination of two or more. Cleaning conditions such as the cleaning time and the temperature of the cleaning liquid are not particularly limited and can be appropriately set as needed. The purpose of the drying process is to remove the cleaning solution remaining on the surface of the substrate W. The drying method is not particularly limited, and for example, a method of blowing an inert gas such as nitrogen onto the surface of the substrate W can be cited. Drying conditions such as drying time and drying temperature are not particularly limited and can be appropriately set as needed.

[4. Densification process S104] The densification process (second contact process) S104 is the following process: a second treatment liquid containing a SAM forming material is brought into contact with the surface of the SiO2 _layer 1 after the surface modification process S103. In the region where the film defect C occurs, a hydroxyl group 6 is generated on the surface of the _SiO2 layer 1 by the surface modification process S103. Therefore, as shown in FIG5C, the second treatment liquid is brought into contact with the surface of the _SiO2 layer 1, whereby the SAM molecule 5 can be chemically adsorbed to the region where the film defect C occurs by allowing the SAM molecule 5 to undergo siloxane bonding with the hydroxyl group 6. In this way, the film defect C is repaired, thereby forming a densified SAM 9'. In addition, FIG5C is a schematic diagram showing the appearance of a densified SAM 9'.

The method of bringing the second processing liquid into contact with the substrate W is the same as the method of bringing the first processing liquid into contact with the substrate W in the first contact step S101 described above, so the detailed description of this part is omitted.

The second treatment liquid contains at least a SAM forming material and a solvent, similarly to the first treatment liquid in the first contacting step S101. The second treatment liquid may be of the same type as the first treatment liquid or of a different type. In the case of using a second treatment liquid different from the first treatment liquid, the amount of the SAM forming material and the type of the solvent are not particularly limited. However, the SAM forming material is preferably the same as the SAM forming material of the first treatment liquid.

There is no particular limitation on the conditions for bringing the second processing liquid into contact with the substrate W. For example, the contact time of the second processing liquid (the immersion time in the case where the substrate W is immersed in the second processing liquid) can be appropriately set within the following time range according to the type and concentration of the SAM forming material, the type of the solvent, and the frequency and area of the film defects C in the surface of the SAM 9: within the range of 1 minute to 1440 minutes, preferably within the range of 1 minute to 60 minutes, and more preferably within the range of 1 minute to 5 minutes.

[5. Cleaning Step S105] The cleaning step S105 is a step of removing the second processing liquid from the surface of the _SiO2 layer 1. Specifically, the cleaning step S105 is performed by supplying the cleaning liquid to the surface of the substrate W, thereby replacing the remaining second processing liquid with the cleaning liquid.

The method for bringing the cleaning liquid into contact with the surface of the substrate W is not particularly limited, and examples thereof include the following methods: a method for directly supplying and applying the cleaning liquid to the substrate W; a method for spraying the cleaning liquid onto the substrate W; a method for immersing the substrate W in the cleaning liquid. As a method for applying the cleaning liquid to the surface of the substrate W, for example, the following method can be cited: the cleaning liquid is supplied to the center of the surface of the substrate W while the substrate W is rotated at a fixed speed with the center of the substrate W as an axis. In this way, the cleaning liquid supplied to the surface of the substrate W flows from the vicinity of the center of the surface of the substrate W toward the periphery of the substrate W by the centrifugal force generated by the rotation of the substrate W, and diffuses to the entire surface of the substrate W. As a result, the entire surface of the substrate W is covered with the cleaning liquid, so that a liquid film of the cleaning liquid can be formed and the processing liquid can be replaced with the cleaning liquid. In addition, the time of the cleaning step S105 is not particularly limited and can be appropriately changed as needed.

Examples of the cleaning liquid include toluene, decane, and 1,3-bis(trifluoromethyl)benzene. These solvents may be used alone or in combination of two or more. Cleaning conditions such as the cleaning time and the temperature of the cleaning liquid are not particularly limited and may be appropriately set as needed.

It is preferred that a drying process be performed immediately after the cleaning process S105 is completed, and the purpose of the drying process is to remove the cleaning solution remaining on the surface of the substrate W. The drying method is not particularly limited, and for example, a method of blowing an inert gas such as nitrogen onto the surface of the substrate W can be cited. Drying conditions such as drying time and drying temperature are not particularly limited and can be appropriately set as needed.

As described above, in the SAM forming step S1, a SAM 9' having excellent density and protective performance can be formed on the surface of the SiO ₂ layer 1 as shown in FIG2B. In the SAM forming step S1, in order to form a dense SAM 9' film, the surface of the SiO ₂ layer 1 is subjected to surface modification to the area (film defect C) where the SAM molecules cannot be chemically adsorbed. Furthermore, the SAM molecules 5 are chemically adsorbed on the area to which the surface modification has been applied, thereby repairing the film defect C. As a result, a SAM 9' film can be formed in a shorter time than the previous method; the SAM 9' has a high film density and excellent density, can suppress or reduce the occurrence of film defects, and has an excellent function as a protective film. In addition, FIG2B is a partially enlarged view showing a SAM 9' formed on the surface of the SiO ₂ layer 1.

[Etching process S2] The etching process S2 is a process of selectively etching the SiN layer 2, which is a sacrificial layer and also an etched layer. More specifically, it is a process of allowing the etching liquid to contact the SiN layer 2 through the memory trench 4, thereby removing the SiN layer 2. In the etching process S2, SAM 9 functions as a protective layer to protect the SiO ₂ layer 1. Thereby, the etching of the SiO ₂ layer 1 can be well suppressed.

As a method for applying the etching liquid to the surface of the substrate W, for example, the following method can be cited: the etching liquid is supplied to the center of the surface of the substrate W while the substrate W is rotated at a constant speed with the center of the substrate W as an axis. In this way, the etching liquid supplied to the surface of the substrate W flows from the vicinity of the center of the surface of the substrate W toward the peripheral portion of the substrate W by the centrifugal force generated by the rotation of the substrate W, and diffuses to the entire surface of the substrate W. As a result, the entire surface of the substrate W is covered with the etching liquid, thereby forming an etching liquid film.

The etching liquid can be appropriately set in consideration of the constituent material of the etched layer and the etching rate. As in the present embodiment, when the etched layer is the SiN layer 2, for example, a phosphoric acid (H ₃ PO ₄ ) aqueous solution or hydrofluoric acid (for example, HF:DIW=1:100 in terms of volume ratio) can be used as the etching liquid. In addition, the concentration of the etching liquid can also be appropriately set in consideration of the constituent material of the etched layer and the etching rate.

In addition, as the etching temperature (ie, the liquid temperature of the etching solution) and the etching rate with respect to the etched layer, the constituent material of the etched layer can be appropriately set in consideration.

In addition, it is preferred to sequentially perform a cleaning process and a drying process for removing the etching liquid just after the etching process S2 is completed. The cleaning method in the cleaning process is not particularly limited, and for example, the following methods can be cited: a method for supplying a cleaning liquid to the surface of the substrate W; a method for immersing the substrate W in the cleaning liquid. The cleaning liquid is not particularly limited, and for example, DIW can be cited. In addition, cleaning conditions such as the cleaning time and the temperature of the cleaning liquid are not particularly limited, and can be appropriately set as needed. The purpose of the drying process is to remove the cleaning liquid remaining on the surface of the substrate W. The drying method is not particularly limited, and for example, a method for blowing an inert gas such as nitrogen onto the surface of the substrate W can be cited. Drying conditions such as the drying time and the drying temperature are not particularly limited, and can be appropriately set as needed.

As described above, in the etching process S2, only the SiN layer 2 shown in FIG. 2B can be selectively removed as shown in FIG. 2C. In the SiO2 layer ₁ , since the SAM9 with excellent density and protective performance covers and protects the surface of the _SiO2 layer 1, it is possible to prevent the _SiO2 layer 1 from being etched and prevent the etched silicon components from being separated and attached to the surface of the SiO2 layer _1. Furthermore, the permissible range of the silicon concentration contained in the etching solution such as phosphoric acid can also be increased. In addition, FIG. 2C is a partial enlarged view of the portion surrounded by B in the layer stack of FIG. 1B, and is a view of the SiN layer 2 after etching.

[Semiconductor manufacturing apparatus] Next, the semiconductor manufacturing apparatus of this embodiment is described below with reference to the drawings. The semiconductor manufacturing apparatus of this embodiment at least has: a substrate processing unit for forming a SAM; and an etching processing unit for etching an etched layer. In addition, the semiconductor manufacturing apparatus of this embodiment may also have: a control unit for controlling each unit of the semiconductor manufacturing apparatus.

[Substrate processing unit 100] The substrate processing unit 100 of this embodiment is a blade-type processing unit used for forming SAM, and as shown in FIG6, at least has: a substrate holding part 110 for holding the substrate W; a supply part 120 for supplying the first processing liquid and the second processing liquid to the surface Wf of the substrate W; a removal liquid supply part 130 for supplying the removal liquid; a surface modification liquid supply part (surface modification part) 140; a chamber 150 for accommodating the substrate W; a scattering prevention cover 160 for collecting the processing liquid; and a rotation drive part 170 for independently rotationally driving the arm parts of each part of the substrate processing unit 100 described later. In addition, the substrate processing unit 100 can also have: a loading and unloading mechanism (not shown) for loading or unloading the substrate W. In addition, FIG. 6 is an explanatory diagram showing the schematic structure of the substrate processing unit 100 of the present embodiment. In FIG. 6 , in order to clarify the directional relationship of the diagram, the XYZ orthogonal coordinate axes are appropriately displayed. Here, the XY plane represents the horizontal plane, and the +Z direction represents the upward direction.

[1. Substrate holding part 110] The substrate holding part 110 is a mechanism for holding the substrate W, and as shown in FIG6 , the substrate W is held in a substantially horizontal position and rotated in a state where the surface Wf of the substrate W is facing upward. The substrate holding part 110 includes: a spin chuck 113, which is formed by integrally combining a spin base 111 and a rotation shaft 112. The spin base 111 has a substantially circular shape when viewed from above, and a hollow rotation shaft 112 is fixed to the center of the spin base 111, and the rotation shaft 112 extends in a substantially vertical direction. The rotation shaft 112 is connected to the rotation shaft of a chuck rotation mechanism 114, and the chuck rotation mechanism 114 includes a motor. The clamp rotating mechanism 114 is housed in a cylindrical casing 115, and the rotating shaft 112 is supported by the casing 115 in a manner that allows it to rotate freely around a rotating shaft in the vertical direction.

The clamp rotating mechanism 114 can rotate the rotating support shaft 112 around the rotating axis by being driven by the clamp driving unit (not shown) of the control unit 300. Thereby, the rotating base 111 mounted on the upper end of the rotating support shaft 112 rotates around the rotating axis J1. The control unit 300 can control the clamp rotating mechanism 114 through the clamp driving unit, thereby adjusting the rotating speed of the rotating base 111.

A plurality of chuck pins 116 are vertically arranged near the periphery of the rotating base 111, and the plurality of chuck pins 116 are used to grip the peripheral end portion of the substrate W. The number of chuck pins 116 to be arranged is not particularly limited, but in order to securely hold the circular substrate W, it is preferably provided with at least three or more. In the present embodiment, three chuck pins 116 are arranged at equal intervals along the periphery of the rotating base 111. Each chuck pin 116 includes: a substrate support pin that supports the periphery of the substrate W from below; and a substrate retaining pin that presses the outer peripheral end surface of the substrate W supported by the substrate support pin and retains the substrate W.

[2. Supply unit 120] The supply unit 120 of this embodiment is a mechanism for supplying the first processing liquid and the second processing liquid to the surface Wf of the substrate W. As shown in FIG6 , the supply unit 120 has a processing liquid storage unit 121, a nozzle 122, and an arm 123.

In the case where the processing liquid storage part 121 uses the same type of processing liquid as the first processing liquid and the second processing liquid, a pressurizing part 124 and a processing liquid cylinder tank 125 are provided as shown in Figure 7. In addition, Figure 7 is an explanatory diagram showing the schematic structure of the processing liquid storage part 121 in the supply part 120 of the substrate processing unit 100.

The pressurizing portion 124 includes: a nitrogen gas supply source 124a, which is a gas supply source for pressurizing the interior of the processing liquid cylinder tank 125; a pump (not shown) for pressurizing the nitrogen gas; a nitrogen gas supply pipe 124b; and a valve 124c, which is disposed midway along the path of the nitrogen gas supply pipe 124b.

Nitrogen supply pipe 124b is connected to the processing fluid cylinder groove 125 by pipeline. Furthermore, valve 124c is provided in the path midway of nitrogen supply pipe 124b. Valve 124c is electrically connected with control unit 300, and the opening and closing of valve 124c can be controlled by the action instruction of control unit 300. When valve 124c is opened by the action instruction of control unit 300, nitrogen can be supplied to the processing fluid cylinder groove 125.

The treatment liquid cylinder tank 125 may also be equipped with: a stirring part (not shown), which stirs the treatment liquid in the treatment liquid cylinder tank 125; and a temperature adjustment part (not shown), which adjusts the temperature of the treatment liquid. As the stirring part, a stirring part having a rotating part and a stirring control part can be cited, the rotating part is used to stir the treatment liquid, and the stirring control part is used to control the rotation of the rotating part. The stirring control part is electrically connected to the control part 300, and the rotating part is, for example, equipped with a screw-shaped stirring wing at the lower end of the rotating shaft. The control part 300 performs an action instruction on the stirring control part, thereby rotating the rotating part, so that the treatment liquid can be stirred with the stirring wing. This result can be set to evenly the concentration and temperature of the treatment fluid in the inside of the treatment fluid cylinder groove 125.

Furthermore, a discharge pipe 125a is connected to the treatment fluid cylinder groove 125 pipeline, and the discharge pipe 125a is used for supplying the treatment fluid to the nozzle 122. A discharge valve 125b is provided in the path of the discharge pipe 125a. In addition, the discharge valve 125b is electrically connected to the control unit 300. Thereby, the opening and closing of these valves can be controlled by the action command of the control unit 300. When the discharge valve 125b is opened by the action command of the control unit 300, the treatment fluid is pumped to the nozzle 122 via the discharge pipe 125a.

The nozzle 122 is mounted on the front end of the arm 123 extending horizontally, and is arranged above the rotating base 111 when spraying the processing liquid. The arm 123 is connected to the rotary drive unit 170 via a rotary shaft (not shown). The rotary drive unit 170 is electrically connected to the control unit 300, and rotates the arm 123 by an action command from the control unit 300. As the arm 123 rotates, the nozzle 122 also moves.

In addition, in the situation of the first treatment solution and the second treatment solution that supply section 120 supplies with kinds different from each other, also can use treatment solution storage section 121 ' as shown in Figure 8, treatment solution storage section 121 ' is to possess a pair of first treatment solution cylinder groove 126 and second treatment solution cylinder groove 127.Thereby, can use the treatment solution that kinds are different respectively in the first contact operation S101 and the densification process S104.Fig. 8 is the explanatory diagram of the schematic structure of the treatment solution storage section 121 ' in the supply section 120 of display substrate processing unit 100.

More specifically, the treatment liquid storage part 121 ' is to have the following structure. That is, the first treatment liquid cylinder groove 126 is to retain the first treatment liquid, and the second treatment liquid cylinder groove 127 is to retain the second treatment liquid. In addition, the nitrogen supply pipe 124b is to branch into the first nitrogen supply pipe 124d and the second nitrogen supply pipe 124e. The first nitrogen supply pipe 124d is connected to the first treatment liquid cylinder groove 126 by pipeline, and the second nitrogen supply pipe 124e is connected to the second treatment liquid cylinder groove 127 by pipeline. Furthermore, the first valve 124f is provided in the middle of the path of the first nitrogen supply pipe 124d, and the second valve 124g is provided in the middle of the path of the second nitrogen supply pipe 124e. Valve 124c, the first valve 124f and the second valve 124g are electrically connected to the control unit 300, and the opening and closing of valve 124c, the first valve 124f and the second valve 124g are controlled by the action command of the control unit 300. When valve 124c, the first valve 124f and the second valve 124g are opened by the action command of the control unit 300, nitrogen can be supplied to the first treatment fluid cylinder groove 126 and the second treatment fluid cylinder groove 127, respectively.

The first treatment fluid cylinder tank 126 and the second treatment fluid cylinder tank 127 may also be provided with: a stirring part (not shown), which stirs the first treatment liquid in the first treatment fluid cylinder tank 126 and the second treatment liquid in the second treatment fluid cylinder tank 127; and a temperature adjustment part (not shown), which adjusts the temperature of the first treatment liquid and the second treatment liquid. As the stirring part, a stirring part having a rotating part and a stirring control part can be cited, the rotating part is used to stir the first treatment liquid or the second treatment liquid, and the stirring control part is used to control the rotation of the rotating part. The stirring control part is electrically connected to the control part 300, and the rotating part is, for example, provided with a screw-shaped stirring wing at the lower end of the rotating shaft. Control unit 300 is to carry out action instruction to stirring control unit, thereby makes rotating part rotate, thereby can stir the first treatment solution or the second treatment solution with stirring wing.This result can be evenly set to the concentration and temperature of the first treatment solution and the second treatment solution in the inside of the first treatment fluid cylinder groove 126 etc.

Furthermore, the first discharge pipe 126a and the second discharge pipe 127a are connected to the first treatment fluid cylinder groove 126 and the second treatment fluid cylinder groove 127 respectively in pipelines, and the first discharge pipe 126a and the second discharge pipe 127a are used to supply the first treatment liquid or the second treatment liquid to the nozzle 122. The first discharge valve 126b is provided in the middle of the path of the first discharge pipe 126a. In addition, the second discharge valve 127b is provided in the middle of the path of the second discharge pipe 127a. Furthermore, the first discharge pipe 126a and the second discharge pipe 127a are connected to the third discharge pipe 128 in pipelines in the mode of converging at the downstream side of the first discharge valve 126b and the second discharge valve 127b. The third discharge valve 128a is provided in the middle of the path of the third discharge pipe 128. In addition, the first discharge valve 126b, the second discharge valve 127b, and the third discharge valve 128a are electrically connected to the control unit 300. Thus, the opening and closing of these valves are controlled by the action command of the control unit 300. When the first discharge valve 126b and the third discharge valve 128a are opened by the action command of the control unit 300, the first processing liquid is pumped to the nozzle 122 through the first discharge pipe 126a and the third discharge pipe 128. In addition, when the second discharge valve 127b and the third discharge valve 128a are opened by the action command of the control unit 300, the second processing liquid is pumped to the nozzle 122 through the second discharge pipe 127a and the third discharge pipe 128.

[3. Removal liquid supply unit 130] The removal liquid supply unit 130 of this embodiment is a mechanism for supplying removal liquid to the surface Wf of the substrate W. As shown in FIG. 6 , the removal liquid supply unit 130 includes a removal liquid storage unit 131, a nozzle 132, and an arm 133.

As shown in Fig. 9, the removal liquid storage part 131 has the function of supplying the removal liquid to the nozzle 132, and has a pressurizing part 134 and a removal liquid cylinder groove 135. Fig. 9 is an explanatory diagram showing the schematic structure of the removal liquid storage part 131 in the removal liquid supply part 130 of the substrate processing unit 100.

The pressurizing part 134 includes: a nitrogen gas supply source 134a, which is a gas supply source for pressurizing the interior of the liquid removal cylinder tank 135; a pump (not shown) for pressurizing nitrogen gas; a nitrogen gas supply pipe 134b; and a valve 134c, which is disposed midway along the nitrogen gas supply pipe 134b.

Nitrogen supply pipe 134b is connected to the removal fluid cylinder groove 135 by pipeline. Furthermore, valve 134c is provided with midway in the path of nitrogen supply pipe 134b. Valve 134c is electrically connected with control unit 300, and can control the opening and closing of valve 134c by the action instruction of control unit 300. When valve 134c is opened by the action instruction of control unit 300, nitrogen can be supplied to the removal fluid cylinder groove 135.

The removal liquid cylinder tank 135 may also be equipped with: a stirring part (not shown), which stirs the removal liquid in the removal liquid cylinder tank 135; and a temperature adjustment part (not shown), which adjusts the temperature of the removal liquid. As the stirring part, a stirring part having a rotating part and a stirring control part can be cited, the rotating part is used to stir the removal liquid in the removal liquid cylinder tank 135, and the stirring control part is used to control the rotation of the rotating part. The stirring control part is electrically connected to the control part 300, and the rotating part is, for example, equipped with a stirring wing in the shape of a screw at the lower end of the rotating shaft. The control part 300 performs an action instruction to the stirring control part, thereby rotating the rotating part, so that the removal liquid can be stirred with the stirring wing. This result can be set to evenly the concentration and temperature of the removal liquid in the inside of the removal liquid cylinder groove 135.

Furthermore, a discharge pipe 135a is connected to the removal liquid cylinder groove 135 pipeline, and the discharge pipe 135a is used to supply the removal liquid to the nozzle 132. A discharge valve 135b is provided midway in the path of the discharge pipe 135a. The discharge valve 135b is electrically connected to the control unit 300. Thereby, the opening and closing of the discharge valve 135b can be controlled by the action command of the control unit 300. When the discharge valve 135b is opened by the action command of the control unit 300, the removal liquid is pumped to the nozzle 132 via the discharge pipe 135a.

The nozzle 132 is mounted on the front end of the horizontally extending arm 133 and is disposed above the rotating base 111 when the removal liquid is sprayed. The arm 133 is connected to the rotary drive unit 170 via a rotary shaft (not shown). The rotary drive unit 170 is electrically connected to the control unit 300 and rotates the arm 133 by an action command from the control unit 300. As the arm 133 rotates, the nozzle 132 also moves.

[4. Surface modification liquid supply unit 140] The surface modification liquid supply unit 140 of this embodiment is a mechanism for supplying the surface modification liquid to the surface Wf of the substrate W. As shown in FIG. 6 , the surface modification liquid supply unit 140 has a surface modification liquid storage unit 141, a nozzle 142, and an arm 143.

As shown in Fig. 10, the surface modification liquid storage part 141 has the function of supplying the surface modification liquid to the nozzle 142, and has a pressurizing part 144 and a surface modification liquid cylinder tank 145. Fig. 10 is an explanatory diagram showing the schematic structure of the surface modification liquid storage part 141 in the surface modification liquid supply part 140 of the substrate processing unit 100.

The pressurizing portion 144 includes: a nitrogen gas supply source 144a, which is a gas supply source for pressurizing the interior of the surface modification liquid cylinder tank 145; a pump (not shown) for pressurizing nitrogen gas; a nitrogen gas supply pipe 144b; and a valve 144c, which is disposed midway along the nitrogen gas supply pipe 144b.

The nitrogen supply pipe 144b is connected to the surface modification liquid cylinder groove 145 by pipeline. Furthermore, a valve 144c is provided in the middle of the path of the nitrogen supply pipe 144b. The valve 144c is electrically connected to the control unit 300, and the opening and closing of the valve 144c can be controlled by the action command of the control unit 300. When the valve 144c is opened by the action command of the control unit 300, nitrogen can be supplied to the surface modification liquid cylinder groove 145.

The surface modification liquid barrel tank 145 may also include: a stirring section (not shown) for stirring the surface modification liquid in the surface modification liquid barrel tank 145; and a temperature adjustment section (not shown) for adjusting the temperature of the surface modification liquid. As the stirring section, there can be cited a stirring section having a rotating section and a stirring control section, wherein the rotating section is used to stir the surface modification liquid in the surface modification liquid barrel tank 145, and the stirring control section is used to control the rotation of the rotating section. The stirring control section is electrically connected to the control section 300, and the rotating section is, for example, provided with a screw-shaped stirring wing at the lower end of the rotating shaft. The control section 300 issues an action instruction to the stirring control section, thereby rotating the rotating section, so that the surface modification liquid can be stirred with the stirring wing. As a result, the concentration and temperature of the surface modification liquid inside the surface modification liquid barrel groove 145 can be set uniformly.

Furthermore, a discharge pipe 145a is connected to the surface modification liquid cylinder tank 145 pipeline, and the discharge pipe 145a is used to supply the surface modification liquid to the nozzle 142. A discharge valve 145b is provided in the middle of the path of the discharge pipe 145a. The discharge valve 145b is electrically connected to the control unit 300. Thereby, the opening and closing of the discharge valve 145b can be controlled by the action command of the control unit 300. When the discharge valve 145b is opened by the action command of the control unit 300, the surface modification liquid is pumped to the nozzle 142 via the discharge pipe 145a.

The nozzle 142 is mounted on the front end of the horizontally extending arm 143 and is disposed above the rotating base 111 when the surface modification liquid is sprayed. The arm 143 is connected to the rotary drive unit 170 via a rotary shaft (not shown). The rotary drive unit 170 is electrically connected to the control unit 300 and rotates the arm 143 by an action command from the control unit 300. As the arm 143 rotates, the nozzle 142 also moves.

[5. Scattering prevention cover 160] The scattering prevention cover 160 is provided so as to surround the rotating base 111. The scattering prevention cover 160 is connected to a lifting drive mechanism (not shown) and can be lifted and lowered in the vertical direction. When the first processing liquid and the like are supplied to the surface Wf of the substrate W, the scattering prevention cover 160 is positioned at a predetermined position by the lifting drive mechanism and surrounds the substrate W held by the clamp pins 116 from a side position. In this way, the first processing liquid and the like scattered from the substrate W and the rotating base 111 can be captured.

[Etching Processing Unit 200] The etching processing unit 200 of this embodiment is a blade-type processing unit used for etching the etched layer, and as shown in FIG11, at least has: a substrate holding part 210 for holding the substrate W; an etching liquid supply part 220 for supplying etching liquid to the surface Wf of the substrate W; a chamber 250 for accommodating the substrate W; a scattering prevention cover 260 for collecting the etching liquid; and a rotation drive part 270 for rotating and driving the arm parts of the etching liquid supply part 220 described later independently. In addition, the etching processing unit 200 can also have: a loading and unloading mechanism (not shown) for loading or unloading the substrate W. In addition, FIG. 11 is an explanatory diagram showing the schematic structure of the etching processing unit 200 of the present embodiment. In FIG. 11 , in order to clarify the directional relationship of the diagram, the XYZ orthogonal coordinate axes are appropriately displayed. Here, the XY plane represents the horizontal plane, and the +Z direction represents the upward direction.

[1. Substrate holding part 210] The substrate holding part 210 is a mechanism for holding the substrate W, and as shown in FIG. 11, the substrate W is held in a substantially horizontal position and rotated in a state where the surface Wf of the substrate W is facing upward. The substrate holding part 210 has: a self-rotating clamp 213, which is formed by integrally combining a self-rotating base 211 and a rotating shaft 212. The self-rotating base 211 has a substantially circular shape when viewed from above, and a hollow rotating shaft 212 is fixed to the center of the self-rotating base 211, and the rotating shaft 212 extends in a substantially vertical direction. The rotating shaft 212 is connected to the rotating shaft of the clamp rotating mechanism 214, and the clamp rotating mechanism 214 includes a motor. The clamp rotating mechanism 214 is housed in a cylindrical housing 215, and the rotating shaft 212 is supported by the housing 215 in a manner that allows it to rotate freely around a rotating shaft in the lead vertical direction.

The clamp rotating mechanism 214 can rotate the rotating support shaft 212 around the rotating axis by being driven by the clamp driving unit (not shown) of the control unit 300. Thereby, the self-rotating base 211 mounted on the upper end of the rotating support shaft 212 rotates around the rotating axis J2. The control unit 300 can control the clamp rotating mechanism 214 through the clamp driving unit, thereby adjusting the rotation speed of the self-rotating base 211.

A plurality of clamp pins 216 are vertically arranged near the periphery of the rotating base 211, and the plurality of clamp pins 216 are used to grip the peripheral end portion of the substrate W. The number of clamp pins 216 to be arranged is not particularly limited, but in order to securely hold the circular substrate W, it is preferably provided with at least three or more. In the present embodiment, three clamp pins 216 are arranged at equal intervals along the periphery of the rotating base 211. Each clamp pin 216 includes: a substrate support pin that supports the periphery of the substrate W from below; and a substrate retaining pin that presses the outer peripheral end surface of the substrate W supported by the substrate support pin and retains the substrate W.

[2. Etching liquid supply unit 220] The etching liquid supply unit 220 of this embodiment is a mechanism for supplying etching liquid to the surface Wf of the substrate W. As shown in FIG. 11 , the etching liquid supply unit 220 has an etching liquid storage unit 221, a nozzle 222, and an arm unit 223.

As shown in Fig. 12, the etching liquid storage part 221 has at least an etching liquid tank 224, a temperature regulator 225, a liquid delivery pump 226, and a particle filter 227. In addition, Fig. 12 is an explanatory diagram of the schematic structure of the etching liquid storage part 221 in the etching liquid supply part 220.

The etching liquid barrel tank 224 may also be provided with a stirring section (not shown) for stirring the etching liquid in the etching liquid barrel tank 224. As the stirring section, a stirring section having a rotating section and a stirring control section can be cited, the rotating section is used to stir the etching liquid, and the stirring control section is used to control the rotation of the rotating section. The stirring control section is electrically connected to the control section 300, and the rotating section is, for example, provided with a stirring wing in the shape of a screw at the lower end of the rotating shaft. The control section 300 issues an action instruction to the stirring control section, thereby rotating the rotating section, so that the etching liquid can be stirred by the stirring wing. As a result, the concentration and temperature of the etching liquid inside the etching liquid barrel tank 224 can be set to be uniform.

The etchant tank 224 is provided with a mixer 228, which can mix a reagent and DIW from an external supply source (not shown) and adjust the etchant to a predetermined concentration. The reagent is a solute that functions as an etchant. Examples of the reagent include phosphoric acid and hydrogen fluoride described above.

In addition, a discharge pipe 229 is connected to the etching liquid tank 224 in a pipeline manner, and the discharge pipe 229 is used to supply the etching liquid to the nozzle 222. A temperature regulator 225, a liquid delivery pump 226 and a particle filter 227 are sandwiched in the middle of the path of the discharge pipe 229 from upstream to downstream. The temperature regulator 225 and the liquid delivery pump 226 are electrically connected to the control unit 300. Thereby, the temperature of the etching liquid supplied to the nozzle 222 can be controlled by the action command of the control unit 300. When the liquid delivery pump 226 is controlled by the action command of the control unit 300, the etching liquid can be pumped to the nozzle 222 through the discharge pipe 229. The particle filter 227 can remove foreign matter such as particles in the etching liquid.

The nozzle 222 is mounted on the front end of the arm 223 extending horizontally, and is arranged above the rotating base 211 when the etching liquid is ejected. The arm 223 is connected to the rotary drive unit 270 via a rotary shaft (not shown). The rotary drive unit 270 is electrically connected to the control unit 300, and rotates the arm 223 by an action command from the control unit 300. As the arm 223 rotates, the nozzle 222 also moves.

[3. Scattering prevention cover 260] The scattering prevention cover 260 is provided so as to surround the rotating base 211. The scattering prevention cover 260 is connected to a lifting drive mechanism (not shown) and can be lifted and lowered in the vertical direction. When the etching liquid is supplied to the surface Wf of the substrate W, the scattering prevention cover 260 is positioned at a predetermined position by the lifting drive mechanism and surrounds the substrate W held by the clamp pin 216 from a side position. In this way, the etching liquid scattered from the substrate W and the rotating base 211 can be captured.

[Control unit 300] The control unit 300 is electrically connected to the semiconductor manufacturing device, that is, electrically connected to each part of the substrate processing unit 100 and the etching processing unit 200, and controls the operation of each part. The control unit 300 is composed of a computer having a computing unit and a memory unit. As the computing unit, a CPU (Central Processing Unit) is used for performing various computing processes. In addition, the memory unit is equipped with: ROM (Read Only Memory), which is a read-only memory used to store substrate processing programs and etching processing programs; RAM (Random Access Memory), which is a freely readable and writable memory used to store various information; and a disk that pre-stores control software and data, etc. The disk pre-stores processing conditions, which include: supply conditions of the first processing liquid, the second processing liquid, the removal liquid, the surface modification liquid, and the etching liquid; cleaning conditions; SAM film formation conditions; and etching conditions, etc. The CPU reads the processing conditions into the RAM, and the CPU controls each part of the semiconductor manufacturing device according to the content of the processing conditions.

[Second embodiment] The following describes a method for manufacturing a semiconductor device and a semiconductor manufacturing device according to the second embodiment of the present invention. The main difference of this embodiment compared to the first embodiment is that the SiN layer 2 is etched to a predetermined depth in the film thickness direction before the SAM is formed on the surface of the SiO ₂ layer 1. With this structure, it is also possible to selectively etch only the SiN layer 2. In addition, in the SiO ₂ layer 1, since the SAM 9' with excellent density and protective performance covers and protects the surface and side of the SiO ₂ layer 1, it is possible to prevent the SiO ₂ layer 1 from being etched and prevent the etched silicon species from being separated and attached to the surface of the SiO ₂ layer 1. Furthermore, the permissible range of silicon concentration contained in an etching solution such as phosphoric acid can be increased.

[Manufacturing method of semiconductor device] The manufacturing method of the semiconductor device of the present embodiment is described below with reference to FIG. 13 and FIG. 14A to FIG. 14C. FIG. 13 is a flow chart showing an example of the overall process of the manufacturing method of the semiconductor device of the second embodiment of the present invention. FIG. 14A is a partial enlarged view showing a sample in which the SiN layer ₂ is locally etched in the film thickness direction to a predetermined depth; FIG. 14B is a partial enlarged view showing a sample in which SAM 9' is formed on the surface of the SiO2 layer 1; and FIG. 14C is a partial enlarged view showing a sample in which the SiN layer 2 is etched.

As shown in FIG. 13 , the method for manufacturing a semiconductor device of the present embodiment includes at least a first etching step S3, a SAM forming step S4, and a second etching step S5, and is capable of stepwise and selectively etching the SiN layer 2 through the memory trench 4 and forming a recess on the side surface of the memory trench 4 in the stack 3.

[First etching step S3] The first etching step S3 is a step of locally and selectively etching the SiN layer 2, which is a sacrificial layer and also an etched layer. More specifically, it is a step of allowing the first etching liquid to contact the SiN layer 2 through the memory trench 4, thereby locally removing the SiN layer 2 in the film thickness direction until reaching a predetermined depth (refer to FIG. 14A).

As a method for applying the first etching liquid to the surface of the substrate W, the same method as the method of applying the etching liquid in the etching step S2 of the first embodiment can be adopted. Therefore, the detailed description of this method is omitted.

The first etching liquid is not particularly limited, and can be appropriately set in consideration of the constituent material of the etched layer and the etching rate. As in the present embodiment, when the etched layer is the SiN layer 2, for example, a phosphoric acid (H ₃ PO ₄ ) aqueous solution or hydrofluoric acid (for example, HF:DIW=1:100 in terms of volume ratio) can be used as the first etching liquid. In addition, the concentration of the first etching liquid is not particularly limited, and can be appropriately set in consideration of the constituent material of the etched layer, the etching rate, and the degree of etching depth in the film thickness direction of the etched layer.

The etching temperature (i.e., the liquid temperature of the first etching solution) and the etching rate for the etched layer are not particularly limited and can be appropriately set in consideration of the constituent material of the etched layer and the etching depth in the film thickness direction of the etched layer.

In addition, it is preferred that a cleaning process and a drying process for removing the first etching solution are sequentially performed immediately after the first etching process S3 is completed. The cleaning process and the drying process are the same as the cleaning process and the drying process performed immediately after the etching process S2 in the first embodiment is completed. Therefore, the detailed description of the cleaning process and the drying process is omitted.

[SAM formation process S4] As shown in FIG. 13, the SAM formation process S4 includes at least a first contact process S101, a removal process S102, a surface modification process S103, a densification process S104, and a cleaning process S105. In the SAM formation process S4, as shown in FIG. 14B, a SAM 9' is formed on the surface of the _SiO2 layer 1. In addition, in the first etching process S3, the SiN layer 2 is etched in the film thickness direction to a predetermined depth, thereby forming a SAM 9' on the side surface of the exposed _SiO2 layer 1.

In the SAM formation step S4, in order to form a dense SAM 9' film, the surface of the _SiO2 layer 1 is subjected to surface modification in the area where the SAM molecules cannot be chemically adsorbed (film defects). Furthermore, the SAM molecules are chemically adsorbed in the area where the surface modification has been applied, thereby repairing the film defects. As a result, the SAM 9' film can be formed in a shorter time than the previous method; the SAM 9' has a high film density and excellent compactness, can suppress or reduce the occurrence of film defects, and has an excellent function as a protective film.

In addition, the first contacting step S101, the removing step S102, the surface modifying step S103, the densifying step S104 and the cleaning step S105 in the SAM forming step S4 are the same as those in the first embodiment. Therefore, the detailed description of each step is omitted.

[Second etching step S5] The second etching step S5 is a step of selectively etching the locally remaining SiN layer 2' and removing the SiN layer 2' completely. More specifically, it is a step of allowing the second etching solution to contact the remaining SiN layer 2' through the memory trench 4 and removing the SiN layer 2' completely.

As a method for applying the second etching liquid to the surface of the substrate W, the same method as the method of applying the etching liquid in the etching step S2 of the first embodiment can be adopted. Therefore, the detailed description of this method is omitted.

The second etching liquid is not particularly limited, and can be appropriately set in consideration of the constituent material of the etched layer and the etching rate. The second etching liquid can be the same type as the first etching liquid or a different type. As in the present embodiment, when the etched layer is the SiN layer 2, for example, a phosphoric acid (H ₃ PO ₄ ) aqueous solution or hydrofluoric acid (for example, HF:DIW=1:100 in terms of volume ratio) can be used as the second etching liquid. In addition, the concentration of the second etching liquid is not particularly limited, and can be appropriately set in consideration of the constituent material of the etched layer, the etching rate, and the degree of etching depth in the film thickness direction of the etched layer.

In addition, the etching temperature (that is, the liquid temperature of the second etching solution) and the etching rate for the etched layer are not particularly limited, and can be appropriately set in consideration of the constituent material of the etched layer, etc.

In addition, it is preferred that a cleaning process and a drying process for removing the second etching solution are sequentially performed immediately after the second etching process S5 is completed. The cleaning process and the drying process are the same as the cleaning process and the drying process performed immediately after the etching process S2 in the first embodiment is completed. Therefore, the detailed description of the cleaning process and the drying process is omitted.

With this configuration, in the second etching step S5, only the SiN layer 2' shown in FIG. 14B can be selectively removed as shown in FIG. 14C. In addition, in the SiO2 layer ₁ , since the SAM 9' with excellent density and protective performance covers and protects the surface and side of the SiO2 layer ₁ , it is possible to prevent the _SiO2 layer 1 from being etched and prevent the etched silicon components from being separated and attached to the surface of the SiO2 layer _1. Furthermore, the permissible range of the silicon concentration contained in the second etching solution such as phosphoric acid can be increased.

[Semiconductor manufacturing apparatus] The semiconductor manufacturing apparatus of the second embodiment is a semiconductor manufacturing apparatus having substantially the same structure as the semiconductor manufacturing apparatus of the first embodiment (see FIGS. 6 to 12 ). Therefore, the same component symbols are attached and the description is omitted.

[Third embodiment] The following describes a method for manufacturing a semiconductor device and a semiconductor manufacturing device according to the third embodiment of the present invention. Compared with the first embodiment, the difference of this embodiment is that the surface modification process is performed by a dry method using ultraviolet irradiation. With this structure, a reaction site such as a hydroxyl group can be formed in an area where the SAM molecule cannot be chemically adsorbed, thereby enabling the SAM molecule to be chemically adsorbed and form a SAM with excellent film density.

[Manufacturing method of semiconductor device] The manufacturing method of the semiconductor device of the present embodiment is described below with reference to FIG. 15. FIG. 15 is a flowchart showing an example of the overall process of the manufacturing method of the semiconductor device of the third embodiment of the present invention. In addition, the first contact process S101, the removal process S102, the densification process S104, and the cleaning process S105 in the SAM formation process S1' shown in FIG. 15 are the same as those of the first embodiment. Therefore, the detailed description of these processes is omitted.

[1. Surface modification step S103'] The surface modification step S103' is a step of modifying the surface of the region where the film defect C occurs in SAM9 into a region where the SAM molecule 5 can be chemically adsorbed, that is, modifying the surface of the region where SAM9 is not formed into a region where the SAM molecule 5 can be chemically adsorbed.

In this embodiment, the surface modification of the surface Wf of the substrate W is performed by a dry method of ultraviolet irradiation. In the case of ultraviolet irradiation, the ultraviolet irradiation conditions such as the wavelength of the light source, the irradiation intensity and the irradiation time are not particularly limited as long as the hydroxyl groups 6 are introduced into the surface of the SiO2 layer ₁ to the extent that the SAM molecules 5 can be chemically adsorbed.

In addition, as described in the first embodiment, in the case of applying surface modification by a wet method, it is preferable to perform a washing process for removing the surface modification liquid and a drying process. However, in the dry method of ultraviolet irradiation of this embodiment, the implementation of these processes can be omitted. Therefore, compared with the manufacturing method of the semiconductor device of the first embodiment, it is possible to seek to improve the manufacturing efficiency.

[Semiconductor manufacturing apparatus] Next, the semiconductor manufacturing apparatus of the present embodiment will be described with reference to the drawings. Compared with the semiconductor manufacturing apparatus of the first embodiment, the difference of the semiconductor manufacturing apparatus of the present embodiment is that, as shown in FIG16, the surface modification liquid supply unit 140 in the substrate processing unit 100' is changed to an ultraviolet irradiation unit 190. FIG16 is an explanatory diagram showing the schematic structure of the substrate processing unit 100' of the third embodiment. In FIG16, in order to clarify the directional relationship of the diagram, the XYZ orthogonal coordinate axes are also appropriately displayed. Here, the XY plane represents a horizontal plane, and the +Z direction represents a vertically upward direction. In addition, the same component symbols are attached to the components having the same functions as the semiconductor manufacturing apparatus of the first embodiment, and detailed descriptions are omitted.

The ultraviolet irradiation unit 190 is disposed above the substrate holding unit 110 (in the direction indicated by arrow Z in FIG. 16 ) in the interior of the substrate processing unit 100 ′, so as to irradiate ultraviolet rays to the surface Wf of the substrate W held by the substrate holding unit 110. The ultraviolet irradiation unit 190 includes at least quartz glass 192 and a plurality of light source units 191.

The light source unit 191 shown in FIG16 is a linear light source, and is arranged so that the long side direction of the light source unit 191 is parallel to the direction indicated by the arrow Y in FIG16 . In addition, each light source unit 191 is arranged in a manner of being equally spaced from each other in the direction indicated by the arrow X. However, the light source unit 191 of the present invention is not limited to this aspect. For example, it may also be the following aspect: a ring-shaped light source unit, and light source units with different diameters are arranged in a concentric circle shape. In addition, the light source unit may also be a point light source. In this case, it is preferred that a plurality of light source units are arranged so as to be equally spaced from each other within a plane.

The type of light source unit 191 is not particularly limited, and for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a potassium lamp, a mercury xenon lamp, a flash lamp, an excimer lamp, a metal halide lamp, and a UV-LED (UltraViolet-Light Emitting Diode) can be used. In addition, the plurality of light source units 191 may be of the same type or of different types. In the case of using a plurality of light source units of different types as the light source unit 191, they may be arranged so that the peak wavelength and light intensity are different from each other.

The quartz glass 192 is disposed between the light source unit 191 and the substrate W. The quartz glass 192 is a plate-shaped body and is arranged parallel to the horizontal direction. In addition, the quartz glass 192 has light transmittance, heat resistance, and corrosion resistance to ultraviolet rays, and can allow the ultraviolet rays irradiated from the light source unit 191 to penetrate and irradiate toward the surface Wf of the substrate W. Furthermore, the quartz glass 192 can protect the light source unit 191 from the atmosphere in the chamber 150.

[Fourth embodiment] The following describes a method for manufacturing a semiconductor device and a semiconductor manufacturing device according to the fourth embodiment of the present invention. Compared with the first embodiment, the present embodiment is different in that the surface modification process is performed by a dry method by supplying ozone gas or gas containing water. With this structure, a reaction site such as a hydroxyl group can be formed in an area where the SAM molecule cannot be chemically adsorbed, thereby enabling the SAM molecule to be chemically adsorbed and form a SAM with excellent film density.

[Manufacturing method of semiconductor device] The manufacturing method of the semiconductor device of the present embodiment is described below with reference to FIG. 17. FIG. 17 is a flowchart showing an example of the overall process of the manufacturing method of the semiconductor device of the fourth embodiment of the present invention. In addition, the first contact process S101, the removal process S102, the densification process S104 and the cleaning process S105 in the SAM formation process S1" shown in FIG. 17 are the same as those of the first embodiment. Therefore, the detailed description of these processes is omitted.

[1. Surface modification step S103”] The surface modification step S103” is the following step: modifying the surface of the region where the film defect C occurs in SAM9 into a region where the SAM molecule 5 can be chemically adsorbed, that is, modifying the surface of the region where SAM9 is not formed into a region where the SAM molecule 5 can be chemically adsorbed.

In the present embodiment, the surface modification of the surface of the _SiO2 layer 1 is performed by a dry method using ozone gas or a gas containing water. In the case of surface modification by these methods, the surface Wf of the substrate W is sprayed with ozone gas or a gas containing water, or the surface Wf of the substrate W is exposed to an atmosphere of ozone gas or a gas containing water, thereby introducing hydroxyl groups 6 to the surface of the _SiO2 layer 1. The concentration of ozone contained in the ozone gas or the amount of water contained in the gas containing water is not particularly limited as long as the hydroxyl groups 6 can be introduced to the surface of the SiO2 layer ₁ to the extent that the SAM molecules 5 can be chemically adsorbed. In addition, the contact time of the ozone gas or the gas containing water is not particularly limited as long as the hydroxyl groups 6 can be introduced to the surface of the SiO2 layer ₁ to the extent that the SAM molecules 5 can be chemically adsorbed.

[Semiconductor manufacturing apparatus] Next, the semiconductor manufacturing apparatus of this embodiment will be described with reference to the drawings. In addition, in the following embodiment, the semiconductor manufacturing apparatus is described as an example in which the semiconductor manufacturing apparatus is equipped with an ozone gas supply unit for supplying ozone gas, but the same structure as the gas supply unit for supplying gas containing water can also be adopted.

Compared with the semiconductor manufacturing apparatus of the first embodiment, the difference of the semiconductor manufacturing apparatus of the present embodiment is that, as shown in FIG18, the surface modification liquid supply unit 140 in the substrate processing unit 100" is replaced with an ozone gas supply unit 193. In addition, FIG18 is an explanatory diagram showing the schematic structure of the semiconductor manufacturing apparatus of the fourth embodiment. In FIG18, in order to clarify the directional relationship of the diagram, the XYZ orthogonal coordinate axes are also appropriately displayed. Here, the XY plane represents a horizontal plane, and the +Z direction represents a vertically upward direction. In addition, the same component symbols are attached to the components having the same functions as the semiconductor manufacturing apparatus of the first embodiment, and detailed descriptions are omitted.

The ozone gas supply unit 193 is a mechanism for supplying ozone gas to the surface Wf of the substrate W. As shown in FIG18 , the ozone gas supply unit 193 includes an ozone gas supply source 194, an ozone gas supply pipe 195, a valve 196, a nozzle 197, and an arm 198. The ozone gas supply pipe 195 supplies ozone gas from the ozone gas supply source 194 to the nozzle 197. A valve 196 is provided in the middle of the path of the ozone gas supply pipe 195. In addition, the valve 196 is electrically connected to the control unit 300. Thus, the opening and closing of the valve 196 can be controlled by the action command of the control unit 300. When the valve 196 is opened by an operation command of the control unit 300 , the ozone gas is pumped to the nozzle 197 through the ozone gas supply pipe 195 .

The nozzle 197 is mounted on the front end of the arm 198 extending horizontally, and is arranged above the rotating base 111 when the ozone gas is sprayed. The arm 198 is connected to the rotary drive unit 170 via a rotary shaft (not shown). The rotary drive unit 170 is electrically connected to the control unit 300, and rotates the arm 198 by an action command from the control unit 300. As the arm 198 rotates, the nozzle 197 also moves.

[Other matters] The above description has described the best implementation of the present invention. However, the present invention is not limited to this implementation. The implementation forms and each configuration in each variation described above can be changed, modified, replaced, added, deleted and combined as long as they are not contradictory.

[Examples] The following is a detailed description of preferred embodiments of the present invention. However, unless otherwise specifically stated, the materials, blending amounts, and conditions described in the embodiments are not limited to these scopes.

[Example 1] A substrate having a _SiO2 film (thickness 100 nm) formed on the surface was prepared and immersed in a hydrofluoric acid aqueous solution for one minute. As the hydrofluoric acid aqueous solution, a hydrofluoric acid aqueous solution with a volume ratio of hydrofluoric acid to DIW of hydrofluoric acid:DIW=1:100 was used.

Next, the substrate picked up from the hydrofluoric acid aqueous solution is immersed in a first treatment liquid containing a SAM forming material for five minutes, thereby forming a SAM (thickness of about 1 nm) on the surface of the _SiO2 film of the substrate (first contact process). As the first treatment liquid, a liquid in which octadecyltrichlorosilane, which is a SAM forming material, has been dissolved in toluene, which is a solvent, is used. In addition, the content (concentration) of octadecyltrichlorosilane is 5% by mass relative to the total mass of the first treatment liquid.

Next, the substrate picked up from the first treatment liquid was continuously supplied with a removal liquid for one minute to remove the unadsorbed SAM forming material remaining on the surface of the substrate (removal step). Decane was used as the removal liquid.

Next, the substrate picked up from the removal liquid was immersed in the surface modification liquid for one minute (surface modification process). As the surface modification liquid, SC-1 (in terms of volume ratio, ammonia water (NH ₃ concentration is 28%): hydrogen peroxide water (H ₂ O ₂ concentration is 30%): DIW = 1:4:20) was used. After that, the substrate was picked up from the surface modification liquid, and nitrogen gas was sprayed on the surface where the SAM was formed to dry the surface. The temperature of the nitrogen gas was set to room temperature, and the drying time was set to 0.33 minutes.

Furthermore, the dried substrate is immersed in a second treatment liquid containing a SAM forming material for five minutes to form a SAM on the surface of the substrate (second contact process (densification process)). As the second treatment liquid, the same treatment liquid as the first treatment liquid in the first contact process is used.

Next, toluene was continuously supplied to the substrate picked up from the second treatment liquid for one minute to remove the second treatment liquid (cleaning step), and then nitrogen gas was sprayed to the surface where the SAM was formed to dry the surface. The temperature of the nitrogen gas was set to room temperature, and the drying time was set to 0.33 minutes. In this way, the sample of this embodiment was produced.

Next, the obtained sample is subjected to etching treatment. Specifically, the substrate is immersed in an etching solution, and the area on the substrate surface that is not protected by the SAM is etched (etching process). As etching conditions, the immersion time in the etching solution (etching treatment time) is set to 195 seconds so that the etching amount of _SiO2 becomes about 10nm. In addition, as an etching solution, a hydrogen fluoride aqueous solution is used, and the volume ratio of hydrogen fluoride to DIW is set to hydrogen fluoride:DIW=1:100.

Next, the substrate picked up from the etching liquid is immersed in DIW for 0.5 minutes, and then the substrate is picked up from the DIW (DIW cleaning process), and nitrogen gas is blown to the surface that has been etched to dry the surface (drying process). The temperature of the nitrogen gas is set to room temperature, and the drying time is set to 0.33 minutes.

[Comparative Example 1] Compared with Example 1, the difference of this Comparative Example 1 is that after the first contact process using the first treatment liquid, the removal process, the surface modification process and the densification process (second contact process) are not performed. A more detailed description is as follows.

A substrate similar to that in Example 1 was prepared and immersed in a hydrofluoric acid aqueous solution for one minute. As the hydrofluoric acid aqueous solution, a hydrofluoric acid aqueous solution having a volume ratio of hydrofluoric acid to DIW of hydrofluoric acid:DIW=1:100 was used.

Next, the substrate picked up from the hydrofluoric acid aqueous solution was immersed in a first treatment liquid containing a SAM forming material for five minutes, thereby forming a SAM (thickness of about 1 nm) on the surface of the _SiO2 film of the substrate. As the first treatment liquid, a liquid in which octadecyltrichlorosilane, which is a SAM forming material, was dissolved in toluene, which is a solvent, was used. In addition, the content (concentration) of octadecyltrichlorosilane was 5% by mass relative to the total mass of the first treatment liquid.

Next, toluene was continuously supplied to the substrate picked up from the first treatment liquid for one minute to remove the first treatment liquid remaining on the surface of the substrate, and then nitrogen gas was sprayed to the surface where the SAM was formed to dry the surface. The temperature of the nitrogen gas was set to room temperature, and the drying time was set to 0.33 minutes. In this way, the sample of this comparative example was produced.

Next, the obtained sample is subjected to etching treatment. Specifically, the substrate is immersed in an etching solution, and the area on the substrate surface that is not protected by the SAM is etched. As etching conditions, the immersion time in the etching solution (etching treatment time) is set to 195 seconds so that the etching amount of _SiO2 becomes about 10nm. In addition, as an etching solution, a hydrogen fluoride aqueous solution is used, and the volume ratio of hydrogen fluoride to DIW is set to hydrogen fluoride:DIW=1:100.

Next, the substrate picked up from the etching liquid is immersed in DIW for 0.5 minutes, and then the substrate is picked up from the DIW (DIW cleaning process), and nitrogen gas is blown to the surface that has been etched to dry the surface (drying process). The temperature of the nitrogen gas is set to room temperature, and the drying time is set to 0.33 minutes.

[Comparative Example 2] Compared with Example 1, the difference of this Comparative Example 2 is that after the removal process of decane, no surface modification process is performed. A more detailed description is as follows.

A substrate similar to that in Example 1 was prepared and immersed in a hydrofluoric acid aqueous solution for one minute. As the hydrofluoric acid aqueous solution, a hydrofluoric acid aqueous solution having a volume ratio of hydrofluoric acid to DIW of hydrofluoric acid:DIW=1:100 was used.

Next, the substrate picked up from the hydrofluoric acid aqueous solution was immersed in a first treatment liquid containing a SAM forming material for five minutes, thereby forming a SAM (thickness of about 1 nm) on the surface of the _SiO2 film of the substrate. As the first treatment liquid, a liquid in which octadecyltrichlorosilane, which is a SAM forming material, was dissolved in toluene, which is a solvent, was used. In addition, the content (concentration) of octadecyltrichlorosilane was 5% by mass relative to the total mass of the first treatment liquid.

Next, the substrate picked up from the first treatment liquid was immersed in a removal liquid for one minute to remove the unadsorbed SAM forming material remaining on the surface of the substrate. Decane was used as the removal liquid.

Next, the substrate was lifted up from the removal liquid, and nitrogen gas was blown to the surface where the SAM was formed to dry the surface. The temperature of the nitrogen gas was set to room temperature, and the drying time was set to 0.33 minutes.

Furthermore, the dried substrate is immersed in a second treatment liquid containing a SAM forming material for five minutes to form a SAM on the surface of the substrate. As the second treatment liquid, the same treatment liquid as the first treatment liquid in the first contact process is used.

Next, toluene was continuously supplied to the substrate picked up from the second treatment liquid for one minute to remove the second treatment liquid, and then nitrogen gas was blown to the surface where the SAM was formed to dry the surface. The temperature of the nitrogen gas was set to room temperature, and the drying time was set to 0.33 minutes. In this way, the sample of this comparative example was produced.

Next, the obtained sample is subjected to etching treatment. Specifically, the substrate is immersed in an etching solution, and the area of the substrate not protected by the SAM is etched. As etching conditions, the immersion time in the etching solution (etching treatment time) is set to 195 seconds so that the etching amount of _SiO2 becomes about 10nm. In addition, as an etching solution, a hydrogen fluoride aqueous solution is used, and the volume ratio of hydrogen fluoride to DIW is set to hydrogen fluoride:DIW=1:100.

Next, the substrate picked up from the etching liquid is immersed in DIW for 0.5 minutes, and then the substrate is picked up from the DIW (DIW cleaning process), and nitrogen gas is blown to the surface that has been etched to dry the surface (drying process). The temperature of the nitrogen gas is set to room temperature, and the drying time is set to 0.33 minutes.

[Evaluation of the density of SAM] The area of the SAM film defects was calculated for each sample of Example 1, Comparative Example 1, and Comparative Example 2, and the density of SAM was evaluated.

That is, an atomic force microscope (AFM; Atomic Force Microscope) (trade name "Dimension Icon", manufactured by Bruker Japan Co., Ltd.) is used to photograph the SAM of each sample, and an observation image (AFM image) of 500nm square is obtained. Then, each observation image obtained is binarized, image processing is performed, and then film defect mapping is performed to identify the location (region) of the SAM film defect. The mapping of the location (region) of the SAM film defect is performed by considering that the film thickness of the SAM is about 1nm, and the image processing is performed in a manner such that the defects located at a depth of less than 1nm from the SAM surface are mapped. Thus, the portion (region) at a depth of more than 1 nm from the SAM surface is mapped as the region of the SAM film defect, and more specifically, the etched portion is mapped as the region of the SAM film defect, and is not included in the area of the region. Then, the area of the region of the SAM film defect identified by image processing is calculated, and the ratio relative to the area of the entire region in the observed image is calculated. The results are shown in Table 1.

As can be seen from Table 1, the area ratio of the film defects of the SAM in Example 1 is 25.4%, which is the smallest compared to the area ratios of the film defects of the SAM in Comparative Examples 1 and 2, confirming good compactness.

[Evaluation of the protective performance of SAM] The protective performance of SAM was evaluated based on the film thickness and water contact angle of the SiO ₂ film for each sample of Example 1, Comparative Example 1, and Comparative Example 2.

Specifically, the film thickness d1 of the SAM-coated _SiO2 film just before etching and the film thickness d2 of the SAM-coated SiO2 film after all the steps were completed were measured using an ellipsometer (trade name: "Flying MASE _XI ", manufactured by JA Woollam Co., Ltd.). The results are shown in Table 1.

In addition, the water contact angle θ1 of the SAM-coated _SiO2 film just before etching and the water contact angle θ2 of the SAM-coated SiO2 film after all the steps were completed were measured using a contact angle meter (trade name "DMo- ₇₀₁ ", manufactured by Kyowa Interface Science Co., Ltd., Japan) based on the drop method. The results are shown in Table 1.

As can be seen from Table 1, in Example 1, the thickness of the _SiO2 film before and after etching changes from 99.6nm to 98.8nm, which is a smaller reduction than that in Comparative Examples 1 and 2. In addition, in Example 1, the water contact angle on the surface of the _SiO2 film after etching is larger than that in Comparative Examples 1 and 2. These results confirm that the protective performance of the SAM of Example 1 for the _SiO2 film is better than that of Comparative Examples 1 and 2.

[Table 1] Embodiment 1 Comparison Example 1 Comparison Example 2 SAM's compactness AFM imaging Mapping imagery Area ratio of film defects (%) 25.4 67.0 55.5 SAM's protective properties The thickness of _SiO2 film is d1 99.6 99.5 96.5 The thickness of _SiO2 film is d2 98.8 95.9 97.5 Water contact angle θ1 of _SiO2 film 101.1 107.3 110.2 Water contact angle θ2 of _SiO2 film 104.4 88.0 101.5

1: SiO ₂ layer 2,2': SiN layer 3: stack 4: memory trench 5: SAM molecule 6: hydroxyl group 7: water molecule 8: reverse micelle 9,9': SAM 100, 100', 100": substrate processing unit 110, 210: substrate holding part 111, 211: self-rotating base 112, 212: rotating support shaft 113, 213: self-rotating clamp 114, 214: clamp rotating mechanism 115, 215: housing 116, 216: clamp pin 120: supply part 121, 121': processing liquid storage part 122, 132, 142, 197, 222: nozzle 123, 133, 143, 198, 223: arm 124, 134, 144: pressurizing part 124a, 134a, 144a: Nitrogen supply source 124b, 134b, 144b: nitrogen supply pipe 124c, 134c, 144c, 196: valve 124d: first nitrogen supply pipe 124e: second nitrogen supply pipe 124f: first valve 124g: second valve 125: treatment liquid cylinder tank 125a, 135a, 145a, 229: discharge pipe 125b, 135b, 145b: discharge valve 126: first treatment liquid cylinder tank 126a: first discharge pipe 126b: first discharge valve 127: second treatment liquid cylinder tank 127a: second discharge pipe 127b: second discharge valve 128: third discharge pipe 128a: third discharge valve 130: removal liquid supply part 131: removal liquid storage part 135: removal liquid cylinder tank 140: surface modification liquid supply part 141: surface modification liquid storage part 145: surface modification liquid cylinder tank 150, 250: chamber 160, 260: scattering prevention cover 170, 270: rotary drive part 190: ultraviolet irradiation part 191: light source part 192: quartz glass 193: ozone gas supply part 194: ozone gas supply source 195: ozone gas supply pipe 200: etching processing unit 220: etching liquid supply part 221 : Etching liquid storage unit 224: Etching liquid tank 225: Temperature regulator 226: Liquid delivery pump 227: Particle filter 228: Mixer 300: Control unit C: Film defects J1, J2: Rotation axis S1, S1', S1": SAM formation step S2: Etching step S3: First etching step S4: SAM formation step S5: Second etching step S101: First contact step S102: Removal step S103, S103', S103": Surface modification step S104: Densification step S105: Cleaning step W: Substrate Wf: Surface (of substrate)

[Figure 1A] is a cross-sectional view schematically showing a layer stack disposed on a substrate, and shows the state before the etching process. [Figure 1B] is a cross-sectional view schematically showing a layer stack disposed on a substrate, and shows the state after the etching process. [Figure 2A] is a partial enlarged view of the portion surrounded by A in the layer stack of Figure 1A. [Figure 2B] is a partial enlarged view showing a state where a SAM is formed on the surface of the _SiO2 layer. [Figure 2C] is a partial enlarged view of the portion surrounded by B in the layer stack of Figure 1B, and shows the state where the SiN layer has been etched. [Figure 3] is a flow chart showing an example of the overall process of a method for manufacturing a semiconductor device according to the first embodiment of the present invention. [FIG. 4A] is a schematic diagram showing the first treatment liquid being supplied to the surface of the _SiO2 layer in the first embodiment. [FIG. 4B] is a schematic diagram showing the SAM molecules being chemically adsorbed on the surface of the _SiO2 layer in the first embodiment. [FIG. 4C] is a schematic diagram showing the SAM molecules being self-assembled on the surface of the _SiO2 layer and forming SAM in the first embodiment. [FIG. 5A] is a schematic diagram showing the surface of the _SiO2 layer after removing the non-adsorbed SAM molecules and reverse micelles in the first embodiment. [FIG. 5B] is a schematic diagram showing the surface modification of the area where no SAM molecules exist and the generation of hydroxyl groups in the first embodiment. [FIG. 5C] is a schematic diagram showing the SAM being densified in the first embodiment. [Figure 6] is an explanatory diagram showing the schematic structure of a substrate processing unit in a semiconductor manufacturing apparatus according to the first embodiment of the present invention. [Figure 7] is an explanatory diagram showing the schematic structure of a processing liquid storage portion provided in a supply portion of a substrate processing unit in a semiconductor manufacturing apparatus according to the first embodiment of the present invention. [Figure 8] is an explanatory diagram showing the schematic structure of other processing liquid storage portions provided in a supply portion of a substrate processing unit in a semiconductor manufacturing apparatus according to the first embodiment of the present invention. [Figure 9] is an explanatory diagram showing the schematic structure of a removal liquid storage portion provided in a removal liquid supply portion of a substrate processing unit in a semiconductor manufacturing apparatus according to the first embodiment of the present invention. [Figure 10] is an explanatory diagram showing the schematic structure of a surface modification liquid storage portion of a surface modification liquid supply portion provided in a substrate processing unit in a semiconductor manufacturing apparatus of the first embodiment of the present invention. [Figure 11] is an explanatory diagram showing the schematic structure of an etching processing unit in a semiconductor manufacturing apparatus of the first embodiment of the present invention. [Figure 12] is an explanatory diagram showing the schematic structure of an etching liquid storage portion of an etching liquid supply portion provided in an etching processing unit in a semiconductor manufacturing apparatus of the first embodiment of the present invention. [Figure 13] is a flow chart showing an example of an overall process of a method for manufacturing a semiconductor device of the second embodiment of the present invention. [Figure 14A] is a partially enlarged diagram showing a state in which a SiN layer is locally etched in the film thickness direction to a predetermined depth. [Fig. 14B] is a partially enlarged view showing a sample in which a SAM is formed on the surface of a _SiO2 layer. [Fig. 14C] is a partially enlarged view showing a sample after an SiN layer is etched. [Fig. 15] is a flow chart showing an example of the overall process of a method for manufacturing a semiconductor device according to the third embodiment of the present invention. [Fig. 16] is an explanatory diagram showing the schematic structure of a substrate processing unit in a semiconductor manufacturing apparatus according to the third embodiment of the present invention. [Fig. 17] is a flow chart showing an example of the overall process of a method for manufacturing a semiconductor device according to the fourth embodiment of the present invention. [Fig. 18] is an explanatory diagram showing the schematic structure of a substrate processing unit in a semiconductor manufacturing apparatus according to the fourth embodiment of the present invention.

1: SiO ₂ layers

2: SiN layer

3:Layered body

4: Memory slot

W: Substrate

Claims (11)

A method for manufacturing a semiconductor device includes processing a substrate having a layer stack disposed on the surface; The layer stack includes a structure formed by alternately stacking a protected layer that is an object of etching and an etched layer that is an object of etching; The method for manufacturing the semiconductor device includes the following steps: Selectively forming a self-assembled monolayer on at least the surface of the protected layer; and Using the self-assembled monolayer as a protective layer, and selectively etching the etched layer; The steps for forming the self-assembled monolayer include: A first contact step, which is to contact a first processing solution containing molecules capable of forming the self-assembled monolayer with the surface of the protected layer, and chemically adsorb the molecules; The removal step is to remove the aforementioned molecules that are not chemically adsorbed from the surface of the aforementioned protected layer; The surface modification step is to modify the surface of the aforementioned protected layer after the aforementioned removal step in the area where the aforementioned molecules do not exist into an area that can be chemically adsorbed by the aforementioned molecules; and The second contacting step is to make a second treatment liquid containing the aforementioned molecules and of the same type or different type as the aforementioned first treatment liquid contact the area that has undergone the aforementioned surface modification, and chemically adsorb the aforementioned molecules. The method for manufacturing a semiconductor device as described in claim 1, wherein the following step is further included before the step for forming the aforementioned self-assembled monolayer: etching the aforementioned etched layer in the film thickness direction until reaching a predetermined depth; The step for forming the aforementioned self-assembled monolayer is the following step: forming the aforementioned self-assembled monolayer in the aforementioned protective layer and also on the side of the aforementioned etched layer exposed by etching. A method for manufacturing a semiconductor device as described in claim 1 or 2, wherein the second contact process is the following process: chemically adsorbing the molecules on the area that has undergone surface modification by the surface modification process, and applying a densification treatment to the self-assembled monolayer formed by the first contact process. A method for manufacturing a semiconductor device as described in claim 1 or 2, wherein the aforementioned protected layer is composed of silicon dioxide; the aforementioned etched layer is composed of silicon nitride; the aforementioned molecule has a functional group capable of siloxane bonding with a hydroxyl group; the surface modification in the aforementioned surface modification step is to generate a hydroxyl group in a region where the aforementioned molecule does not exist; the chemical adsorption of the aforementioned molecule in the aforementioned first contact step and the aforementioned second contact step is to bond the aforementioned molecule to the aforementioned surface via siloxane bonding with the hydroxyl group on the surface of the aforementioned protected layer. The method for manufacturing a semiconductor device as described in claim 4, wherein the surface modification step is the following step: bringing a surface modification liquid into contact with a region on the surface of the protected layer after the removal step where the molecules are not present; and using a solution for generating hydroxyl groups on the surface of the protected layer composed of the silicon dioxide as the surface modification liquid. A method for manufacturing a semiconductor device as described in claim 4, wherein the surface modification step is at least one of the following steps: A step for bringing ozone gas into contact with an area on the surface of the protected layer where the aforementioned molecules do not exist; A step for irradiating ultraviolet light to an area on the surface of the protected layer where the aforementioned molecules do not exist; and A step for bringing a gas containing water into contact with an area on the surface of the protected layer where the aforementioned molecules do not exist. A method for manufacturing a semiconductor device as described in claim 4, wherein the aforementioned molecule comprises octadecyltrichlorosilane. A semiconductor manufacturing device is used to process a substrate having a layer stack disposed on the surface; The layer stack is a structure in which a protected layer serving as a protection object to be etched and an etched layer serving as an object to be etched are alternately stacked; The semiconductor manufacturing device comprises: A substrate processing unit for selectively forming a self-assembled monolayer on at least the surface of the protected layer; and An etching processing unit for using the self-assembled monolayer as a protective layer and selectively etching and removing the etched layer; The substrate processing unit comprises: A supply unit for supplying a processing liquid containing molecules capable of forming the self-assembled monolayer to the surface of the substrate; The removal liquid supply unit supplies the removal liquid to the surface after the treatment liquid is supplied, thereby removing the non-chemically adsorbed molecules; and the surface modification unit modifies the surface after the molecules are removed by the removal liquid supply unit and the area where the molecules do not exist into an area where the molecules can be chemically adsorbed; the supply unit also supplies the treatment liquid to the surface of the substrate after the surface modification by the surface modification unit. The semiconductor manufacturing device as described in claim 8, wherein the etching processing unit etches the etched layer in the film thickness direction to a predetermined depth before forming the self-assembled monolayer; The substrate processing unit forms the self-assembled monolayer in the protective layer and also on the side of the etched layer exposed by etching. A semiconductor manufacturing device as described in claim 8 or 9, wherein the aforementioned protected layer is composed of silicon dioxide; The aforementioned etched layer is composed of silicon nitride; The aforementioned molecule has a functional group capable of siloxane bonding with a hydroxyl group; The aforementioned surface modification section is a surface modification liquid supply section for supplying a surface modification liquid to an area where the aforementioned molecule does not exist; A solution for generating a hydroxyl group on the surface of the aforementioned protected layer is used as the aforementioned surface modification liquid. A semiconductor manufacturing device as described in claim 8 or 9, wherein the aforementioned protected layer is composed of silicon dioxide; the aforementioned etched layer is composed of silicon nitride; the aforementioned molecule has a functional group capable of siloxane bonding with a hydroxyl group; the aforementioned surface modification unit is at least one of an ozone gas supply unit, an ultraviolet irradiation unit, and a gas supply unit, the aforementioned ozone gas supply unit supplies ozone gas to the area on the surface of the aforementioned protected layer where the aforementioned molecule does not exist, the aforementioned ultraviolet irradiation unit irradiates ultraviolet rays to the area on the surface of the aforementioned protected layer where the aforementioned molecule does not exist, and the aforementioned gas supply unit supplies gas containing water to the area on the surface of the aforementioned protected layer where the aforementioned molecule does not exist.