JP2011044520A - Reflective mask and method of manufacturing the same - Google Patents

Abstract

An EUV having a light-shielding band that enhances the light-shielding property of overlapping portions of transfer pattern fields in EUV exposure, suppresses exposure light leakage, reduces the influence of exposure light shadowing, and has excellent cleaning resistance. A reflective mask for exposure and a method for manufacturing the same are provided.
In order to define a transfer pattern formation area on a transfer target and prevent irradiation of EUV light to areas other than the transfer pattern formation area, a predetermined width is formed around the transfer pattern. A light-shielding band 18 is provided, and the light-shielding band 18 is composed of a layer in which the multilayer reflective film 12 is irradiated with laser light to destroy the multilayer reflective film, and is the same as the multilayer reflective film 12 on the substrate 11. It is on a plane, and the reflectance of the light shielding band 18 with respect to the EUV light is lower than the reflectance of the multilayer reflective film 12.
[Selection] Figure 1

Description

  The present invention relates to a method for manufacturing a lithography mask in the manufacture of semiconductor devices and the like, and more particularly to a lithography mask. The present invention relates to a reflective mask for EUV exposure for transfer to a surface and a method for manufacturing the same.

  Along with the miniaturization of semiconductor devices, an exposure method of transferring a pattern onto a wafer using a photomask is currently being performed by an optical projection exposure apparatus using an ArF excimer laser. In these exposure methods using an optical projection exposure apparatus, the resolution limit will eventually be reached. Therefore, new pattern forming methods such as direct drawing using an electron beam drawing apparatus, imprint lithography, and EUV lithography have been proposed.

  Among these new lithography techniques, EUV exposure is a technique in which EUV light having a wavelength shorter than that of an excimer laser and having a wavelength of about 13.5 nm is used, and the exposure is usually reduced to about 1/4. It is regarded as the limit of wavelength conversion, and is attracting attention as a lithography technique for semiconductor devices. In EUV exposure, since a refractive optical system cannot be used due to a short wavelength, a reflective optical system is used, and a reflective mask has been proposed as a mask (see, for example, Patent Document 1). The reflective mask for EUV exposure is a mask in which a pattern is formed by providing at least a multilayer reflective film that reflects EUV light and an absorption layer that absorbs EUV light on the multilayer reflective film.

  FIG. 11 is a sectional view showing an example of such a conventional reflective mask for EUV exposure. A reflective mask 110 for EUV exposure shown in FIG. 11 has a reflective layer 112 that reflects EUV light in a multilayer structure on a substrate 111, a capping layer 113 that protects the reflective layer on the reflective layer 112, and then a mask pattern. A buffer layer 114 is provided in order to prevent etching damage to the reflective layer 112 at the time of formation, and an absorption layer 115 that absorbs EUV light is further formed thereon. An antireflection layer 116 is provided on the absorption layer 115 in order to increase the detection sensitivity at the time of inspection. The reflective mask for EUV exposure is formed by patterning the absorption layer and removing the buffer layer based on the patterned absorption layer 115. The EUV light incident on the reflective mask is reflected by the reflective layer 112, absorbed by the absorption layer 115, and a reduced transfer pattern is formed on the wafer by the reflected EUV light.

  FIG. 8 is a conceptual diagram of EUV exposure. As shown in FIG. 8, in the EUV exposure, the EUV light 81 is incident from a direction inclined several degrees from the direction perpendicular to the EUV mask 80 surface. Therefore, if the thickness of the absorption layer 115 pattern is large, the pattern itself shadows, and a sharp transfer image cannot be obtained due to a phenomenon called shadowing such as blurring of the edge portion of the pattern transferred during exposure. In terms of formation, it is more preferable that the thickness of the absorption layer 115 is thinner. From this point, it is advantageous that the absorption layer 115 has a larger absorption coefficient with respect to the wavelength of the exposure light, and the film thickness of the absorption layer 115 is sufficient to absorb the EUV light 81 as the exposure light. And as thin as possible. In recent years, in particular, the absorption layer 115 is expected to be made thinner in order to improve a problem called three-dimensional shielding derived from the three-dimensional structure of the mask that causes deterioration in resolution performance of the transferred pattern. Yes.

  In the EUV exposure, a region irradiated with the EUV light 81 is divided into rectangles. As shown in FIG. 8, the rectangular area is delimited by a blade 82 installed on the surface of the EUV mask 80. Originally, light that adversely affects the resist should not be generated from the absorption layer 115 of the mask, but the overlapping portion of the exposure field in the vicinity of the blade 82 boundary due to weak reflected light from the absorption layer 115 and light leaked by flare or the like. It is a problem that this resist is exposed to light.

  FIG. 9 is an explanatory diagram of the above-described problem caused by EUV exposure, and illustrates a state in which four exposure fields are transferred onto the wafer 83. As shown in FIG. 9, in the periphery of the field on the wafer, the exposure is overlapped by double or quadruple exposure due to adjacent shots at the time of exposure, or reflected light or leakage light from the exposure field boundary. Due to the effect, resist damage occurs. For example, when a positive resist is used, even if the exposure exposure is appropriate in one exposure shot, the resist in the portion where the field 84 overlaps is overexposed due to multiple exposure, which causes a problem of resist film reduction. The blade 82 that divides the field 84 spreads leaks even if the accuracy is increased, and resist damage is inevitably generated at the boundary portion. Therefore, it is necessary to block multiple exposure at the field boundary portion by some method. With the demand for thinning the absorption layer, the light shielding property of the overlapping portion of the transfer pattern field during EUV exposure has become more important.

  In order to solve the above-described problem of light shielding at the field boundary, as shown in FIG. 10, a reflective mask for EUV exposure in which a light shielding region is provided around the mask transfer pattern has been proposed (see Patent Document 2). ). As shown in FIG. 10, there are two types of EUV exposure reflective masks provided with a light shielding region disclosed in Patent Document 2. As shown in FIG. In FIG. 10A, the second absorber pattern (absorbing film 106) is provided on the first absorbing film 105, and the laminated absorber type reflection type in which the absorbing film in the light shielding region has a two-stage structure. It is a mask. FIG. 10B shows a reflective mask of a multilayer film processing system in which the second absorber pattern is formed by the exposed portion of the substrate 101 and the reflective layer in the light shielding region is removed by etching. Each of the masks shown in FIGS. 10A and 10B is a reflective mask in which a second absorber pattern is provided at a position different from the first absorber pattern.

Japanese Patent Publication No. 7-27198 JP 2009-141223 A

However, in the reflective mask having a laminated absorber type light shielding region as shown in FIG. 10A described in Patent Document 2, the absorption film to be laminated is formed in order to form at least two absorption films. Further, an extra process such as pattern processing becomes necessary, the mask manufacturing process becomes complicated, the control of the mask pattern shape and pattern dimension (CD) becomes difficult, and there is a possibility that the mask pattern accuracy may also be problematic. Further, increasing the thickness of the absorption film does not solve the shadowing or the like, but rather goes against the above-mentioned demand for thinning the absorption layer.
On the other hand, the reflective mask having the light-shielding region of the multilayer film processing method shown in FIG. 10B has 40 layers of reflective layers (thickness of 274 nm) as a set of layers in which Mo and Si are alternately provided. In order to perform deep etching, the mask manufacturing process is complicated and requires processing time, and it is difficult to control the shape of the light shielding region. Furthermore, the mask shown in FIG. 10B exposes the side surfaces of the multilayer film in which Mo and Si are alternately laminated with a thickness of several nanometers. There was a risk of leaching from and damaging the pattern.

  The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to enhance the light shielding property of overlapping portions of transfer pattern fields in EUV exposure to suppress exposure light leakage, and to shadow exposure light. The present invention provides a reflective mask for EUV exposure having a light-shielding region (referred to as a light-shielding band in the present invention) having an excellent effect on cleaning and having a good resistance to washing, and a method for producing the same.

  In order to solve the above-described problems, a reflective mask according to the first aspect of the present invention includes a multilayer reflective film that reflects EUV light on one main surface of a substrate, and the multilayer reflective film on the multilayer reflective film. A reflection type mask for EUV exposure having a transfer pattern formed by providing at least an absorption layer that absorbs EUV light, defining a transfer pattern forming region on a transfer target, and transferring the transfer pattern In order to prevent irradiation of the EUV light to areas other than the pattern formation region, a light shielding band is provided around the transfer pattern, and the light shielding band irradiates the multilayer reflective film with laser light and The multilayer reflective film is composed of a layer that is destroyed, is on the same plane as the multilayer reflective film on the substrate, and the reflectance of the shading band for the EUV light is lower than the reflectance of the multilayer reflective film Is what

  A reflective mask according to a second aspect of the present invention is the reflective mask according to the first aspect, wherein the shading band is sandwiched between the substrate and the absorbing layer and is incorporated in the reflective mask. It is characterized by being.

  A reflective mask according to a third aspect of the present invention is the reflective mask according to the first aspect, wherein the absorbing layer above the light shielding band formed on the substrate is removed, and the light shielding. The surface of the band is exposed.

  According to a fourth aspect of the present invention, there is provided a reflective mask manufacturing method comprising: a multilayer reflective film that reflects EUV light on one main surface of a substrate; and an absorption that absorbs the EUV light on the multilayer reflective film. A method of manufacturing a reflective mask for EUV exposure having a transfer pattern formed by providing at least a layer, defining a transfer pattern formation region on a transfer target, and forming the transfer pattern In order to prevent irradiation of the EUV light to areas other than the region, when providing a light shielding band around the transfer pattern, the multilayer reflection film is irradiated with laser light to the multilayer reflection film around the transfer pattern. And the shading band is formed by the destroyed multilayer reflective film.

  A reflective mask manufacturing method according to claim 5 of the present invention is the reflective mask manufacturing method according to claim 4, wherein the reflective mask for EUV exposure without the light shielding band is prepared, From the other main surface side of the substrate, through the substrate, the multilayer reflective film around the transfer pattern is irradiated with laser light to destroy the multilayer reflective film, and the light-shielding band is formed by the destroyed multilayer reflective film. It is characterized by forming.

  According to a sixth aspect of the present invention, there is provided a method for manufacturing a reflective mask according to the fourth aspect of the present invention, wherein the reflective mask for EUV exposure without the light-shielding band is prepared after the reflective mask is manufactured. A resist pattern for forming the light shielding band is formed on one main surface of the substrate on which the transfer pattern is formed, and the absorption layer is etched using the resist pattern as a mask to form the light shielding band. Exposing the multilayer reflective film, and then irradiating the exposed multilayer reflective film with a laser beam from one main surface side of the substrate to destroy the exposed multilayer reflective film, and the destroyed multilayer The light shielding band is formed by a reflective film.

  A reflective mask manufacturing method according to a seventh aspect of the present invention is the reflective mask manufacturing method according to the fourth aspect, wherein the transfer pattern and the light shielding band are formed using a reflective mask blank. A resist pattern for forming is formed on the absorption layer, the absorption layer is etched using the resist pattern as a mask to expose the multilayer reflective film, and then one of the substrates on which the transfer pattern is formed Irradiating a region of the exposed multilayer reflective film as the light shielding band with a laser beam to destroy the multilayer reflective film, and forming the light shielding band with the broken multilayer reflective film It is a feature.

  According to the reflective mask for EUV exposure of the present invention, the light-shielding band is on the same plane as the multilayer reflective film, and the leakage of exposure light is suppressed by improving the light-shielding property of the overlapping portion of the transfer pattern field in EUV exposure. In addition, the influence of shadowing of the exposure light is reduced, and the side surface of the multilayer reflective film is not exposed, so that a reflective mask for EUV exposure having a light-shielding band with excellent cleaning resistance becomes possible.

  According to the manufacturing method of a reflective mask for EUV exposure of the present invention, a light shielding band material is newly formed in order to form a light shielding band by a layer in which the multilayer reflective film is broken by irradiating the multilayer reflective film with laser light. Therefore, it is possible to manufacture a reflective mask having a light-shielding band in a short time with a simple process without complicating the processing method at the time of mask production. Furthermore, the manufacturing method of a reflective mask for EUV exposure according to the present invention uses a reflection-type mask that has not been provided with a light-shielding region and forms a light-shielding band at a predetermined position of the mask. It is also possible to provide a reflective mask provided.

It is the schematic sectional drawing and top view which show 1st Embodiment in the reflective mask of this invention which has a light-shielding zone. It is a schematic sectional drawing and a top view which show another example of 1st Embodiment in the reflective mask of this invention which has a light-shielding zone. It is the schematic sectional drawing and top view which show 2nd Embodiment in the reflective mask of this invention which has a light-shielding zone. It is a cross-sectional schematic diagram which shows the manufacturing process of a reflective mask. It is a cross-sectional schematic diagram which shows the manufacturing process of 1st Embodiment following FIG. 4 of the reflective mask of this invention which has the light-shielding band shown in FIG. It is a cross-sectional schematic diagram which shows the manufacturing process of 2nd Embodiment of the reflective mask of this invention which has a light-shielding band shown in FIG. It is a cross-sectional schematic diagram which shows the manufacturing process of 3rd Embodiment of the reflective mask of this invention which has a light-shielding band shown in FIG. It is a conceptual diagram of EUV exposure. It is explanatory drawing of the problem of the multiple exposure in the part where the field by EUV exposure overlaps. It is a schematic diagram which shows the cross-section of the reflection type mask which has the conventional light-shielding area | region. It is sectional drawing which shows an example of the reflection type mask for conventional EUV exposure.

  Embodiments of a reflective mask for EUV exposure and a method for manufacturing the same according to the present invention will be described below with reference to the drawings.

<Reflective mask>
1. First Embodiment FIG. 1 is a diagram showing a first embodiment of a reflective mask having a light-shielding band according to the present invention. FIG. 1 (a) is a schematic cross-sectional view, and is a plan view seen from a pattern side. The sectional view in the AA line of Drawing 1 (b) which is is shown. As shown in FIG. 1A, a reflective mask 10 having a light-shielding band according to the present embodiment includes a multilayer reflective film 12 that reflects EUV light on one main surface of a substrate 11, and the multilayer reflective film 12 on the multilayer reflective film 12. Is a mask having a transfer pattern formed by providing at least an absorption layer 15 for absorbing EUV light, defining a transfer pattern formation region on a transfer object such as a wafer, and forming a transfer pattern In order to prevent irradiation of EUV light to areas other than the area, a light shielding band 18 having a predetermined width is provided in the light shielding area around the transfer pattern. In FIG. 1, a region where a transfer pattern is formed as a field on a transfer object such as a wafer is a transfer pattern region 21, and a surrounding light shielding region other than the transfer pattern forming region is a peripheral light shielding region 22. The light-shielding band 18 is provided in a region that is in the peripheral light-shielding region 22 and is subjected to multiple exposure during exposure. Therefore, the portion provided with the light shielding band 18 in the peripheral light shielding region 22 has a higher light shielding property by the two layers of the absorption layer 15 and the light shielding band 18. The outer side of the light shielding band 18 can be shielded with a blade during exposure.
Hereinafter, the light shielding band 18 constituting the low reflection mask 10 of the present invention will be described in more detail.

(Shading zone)
The light shielding band 18 of the present embodiment is configured by a layer in which the multilayer reflective film 12 is irradiated with laser light to destroy the multilayer reflective film 12, and is on the same plane as the multilayer reflective film 12 on the substrate 11. The light-shielding band 18 has a reflectivity lower than that of the multilayer reflective film 12. Further, as shown in FIG. 1A, the light shielding band 18 is sandwiched between the substrate 11 and the absorption layer 15 (through a capping layer 13 and a buffer layer 14 described later in FIG. 1A). It is incorporated in a reflective mask. Therefore, the existence of the light shielding band 18 cannot be confirmed in FIG. FIG. 1B shows that the light shielding band 18 is built in a frame surrounded by a dotted line and a solid line. However, when the substrate 11 is transmissive, the light shielding band 18 can be confirmed from the other main surface side opposite to the patterned main surface side. In the present invention, the width of the light shielding band 18 is usually a predetermined value within a range of about 1 mm to 10 mm in the quadruple mask, and is provided in a rectangular track shape around the transfer pattern.

  In the present invention, the light shielding band 18 is composed of a layer in which the multilayer reflective film is destroyed by laser light irradiation. The multilayer reflective film 12 is generally formed of a multilayer structure in which a plurality of thin films of several tens of layers are alternately stacked, and serves as a multilayer film reflector. Typically, the material is a Mo / Si multilayer reflective film. Membranes are often used. However, it is known that a multilayer reflective film having a multilayer structure is vulnerable to high heat.

  In the present invention, the multilayer reflective film irradiated with the laser beam is destroyed. For example, in the case of a multilayer reflective film of Mo and Si, the multilayer reflective film is melted by the heat of the laser light and Mo and Si are alloyed, or Mo It is unclear whether Si and Si form a diffusion layer or other structure, but the function as a multilayer reflective film is destroyed by laser light irradiation, and the part irradiated with laser light is EUV light On the other hand, if the layer has a lower reflectance than the multilayer reflective film, it can be used as a light shielding zone. Therefore, the light shielding band 18 does not necessarily have to be destroyed in all layers of the multilayer reflective film. For example, if the layer on the substrate 11 side is broken even if the layer on the pattern side of the multilayer reflective film laminated in several tens of layers by laser beam irradiation from the substrate 11 side is not damaged, The reflectance is lowered and can be used as a light-shielding band of the present invention.

(Other components)
In the reflective mask 10, the absorption layer 15 that forms the pattern does not necessarily have to be in direct contact with the multilayer reflective film 12. In order to prevent damage to the lower multilayer reflective film 12 when the absorbent layer 15 is dry-etched into a pattern, usually a buffer layer (also referred to as an etching stopper layer) is provided between the multilayer reflective film 12 and the absorbent layer 18. ) 14 is provided. Further, if necessary, a capping layer (also referred to as a protective layer) 13 is provided on the multilayer reflective film 12 to prevent oxidation of the reflective film. In addition, an antireflection layer 16 may be provided on the absorption layer 15 in order to increase the reflection contrast of inspection light (250 nm) during mask inspection.
In the reflective mask of this embodiment, the components and materials of the conventional reflective mask can be applied as they are as the other components and materials other than the light-shielding band 18, and will be described below.

(substrate)
The substrate 11 of the reflective mask 10 of the present invention has a low thermal expansion coefficient in order to maintain high pattern position accuracy, and has high smoothness and flatness in order to obtain high reflectivity and transfer accuracy. A glass substrate having excellent resistance to a cleaning solution used for cleaning in the manufacturing process is preferable. Glass substrate such as quartz glass, SiO ₂ —TiO ₂ low thermal expansion glass, crystallized glass on which β quartz solid solution is deposited, and silicon It can also be used. As the flatness of the mask blank, for example, 50 nm or less is required in the pattern region.

(Multilayer reflective film)
The multilayer reflective film 12 is made of a material that reflects EUV light used for EUV exposure with high reflectivity, and a multilayer film made of Mo and Si is frequently used. For example, Mo having a thickness of 2.74 nm and 4.11 nm are used. The reflective film which consists of a multilayer film which laminated | stacked 40 each of Si of this is mentioned. Other than that, as a material capable of obtaining a high reflectance in a specific wavelength range, Ru / Si, Mo / Be, Mo compound / Si compound, Si / Nb periodic multilayer film, Si / Mo / Ru periodic multilayer film, Si / Mo / Ru / Mo periodic multilayer film and Si / Ru / Mo / Ru periodic multilayer film can also be used. However, the optimum film thickness varies depending on the material. In the case of a multilayer film composed of Mo and Si, a Si film is first formed in an Ar gas atmosphere using a Si target by a DC magnetron sputtering method, and then a Mo film is used in an Ar gas atmosphere using a Mo target. Is formed as a cycle, and laminated for 30 to 60 cycles, preferably 40 cycles, to obtain a multilayer reflective film. As described above, in order to reflect EUV light with a high reflectance, the reflectance of the multilayer reflective film 12 when 13.4 nm EUV light is incident at an incident angle of 6.0 degrees is normally 60% or more. It is set as shown.

(Capping layer)
In order to increase the reflectivity of the multilayer reflective film 12, it is preferable to use Mo having a large refractive index as the uppermost layer. However, since Mo is easily oxidized in the atmosphere and the reflectivity is reduced, it is possible to prevent oxidation and protect during mask cleaning. As a protective film for this purpose, a capping layer 13 may be provided by depositing Si or Ru by sputtering or the like. For example, Si is provided as a capping layer 13 on the uppermost layer of the multilayer reflective film 12 to a thickness of 11 nm.

(Buffer layer)
In order to prevent damage to the lower multilayer reflective film 12 when pattern-etching the absorbing layer 15 that absorbs EUV light used for EUV exposure by a method such as dry etching, A buffer layer 14 is provided between the absorption layer 15. Although SiO ₂ is frequently used as the material of the buffer layer 14, Al ₂ O ₃ , Cr, CrN, or the like may be used as a material having high etching resistance depending on conditions for etching the absorption layer. When SiO ₂ is used, it is preferable to form a SiO ₂ film with a film thickness of about ₅ nm to 15 nm on the multilayer reflective film in an Ar gas atmosphere using an SiO ₂ target by RF magnetron sputtering.

(Absorption layer)
The material of the absorption layer 15 that forms a mask pattern and absorbs EUV light is at least selected from materials such as Ta, TaB, TaBN, and the like that are mainly Ta, Cr, Cr, and N, O, C. A material containing one component is used in a thickness range of about 30 nm to 100 nm, more preferably in a range of 50 nm to 85 nm.

(Antireflection layer)
Further, in order to increase the detection sensitivity at the time of mask pattern inspection, an antireflection layer 16 having low reflection with respect to inspection light (250 nm) may be provided on the absorption layer 15. Examples of the material of the antireflection layer 16 include tantalum nitride (TaN), oxide (TaO), oxynitride (TaNO), tantalum boron oxide (TaBN), and tantalum boron nitride (TaBN). The film thickness is in the range of about 5 nm to 30 nm.

2. Another Example of First Embodiment FIG. 2 is a schematic cross-sectional view showing another example in the first embodiment of the reflective mask having a light shielding band of the present invention. 2, the same reference numerals as those in FIG. 1 are used to indicate the same parts and materials as those in FIG. In another example of this embodiment shown in FIG. 2, the conductive layer 17 is formed on the other main surface opposite to the mask pattern provided on one main surface of the substrate 11. The other cases are the same as in FIG.

  That is, as shown in FIG. 2, a reflective mask 20 having a light-shielding band as another example of this embodiment includes a multilayer reflective film 12 that reflects EUV light on one main surface of a substrate 11, and the multilayer It has a transfer pattern formed by providing at least an absorption layer 15 that absorbs EUV light on the reflective film 12, and a conductive layer 17 is formed on the other main surface of the substrate 11. A light shielding band 18 having a predetermined width is provided around the transfer pattern area 21 in order to define a transfer pattern formation area on the transfer body and prevent irradiation of EUV light to areas other than the transfer pattern formation area. ing. The light-shielding band 18 is provided in a region that is in the peripheral light-shielding region 22 and is subjected to multiple exposure during exposure. Since the other constituent elements except the conductive layer 17 and the light shielding band 18 are the same as those described in the first embodiment, the description thereof is omitted here. Hereinafter, the conductive layer 17 will be described.

(Conductive layer)
As described above, the conductive layer 17 is provided for the electrostatic chuck of the EUV exposure mask, and the conductive layer 17 is provided with a thin film such as a metal or metal nitride exhibiting conductivity. For example, chromium (Cr), chromium nitride (CrN), or the like is formed to a thickness of about 20 nm to 150 nm.

  In the reflective mask 20 shown in FIG. 2, even if the substrate 11 is transmissive, the light shielding band 18 cannot be confirmed from either the pattern side or the other main surface side opposite to the pattern side. The reflective mask 20 shown in FIG. 2 is a conductive layer 17 on the other main surface side opposite to the pattern side after the reflective mask 10 shown in FIG. Can be obtained by forming a film.

  According to the reflective mask for EUV exposure according to the first embodiment, since the light shielding band 18 is on the same plane as the multilayer reflective film 12, the influence of exposure light shadowing is reduced, and the substrate 11 absorbs the light. Since it is sandwiched between the layer 15 and incorporated in the reflective mask, the mask has excellent cleaning resistance, and the effect of suppressing exposure light leakage by improving the light shielding property of the overlapping portion of the transfer pattern field in EUV exposure. And a good transfer pattern can be obtained.

3. Second Embodiment FIG. 3 is a diagram showing a second embodiment of a reflective mask having a light-shielding band according to the present invention, and FIG. 3 (a) is a schematic sectional view showing a plane viewed from the pattern side. FIG. 5 is a cross-sectional view taken along line BB in FIG. 3, the same reference numerals as those in FIG. 1 are used to indicate the same parts and materials as those in FIG. As shown in FIG. 3A, a reflective mask 30 having a light shielding band according to this embodiment includes a multilayer reflective film 12 that reflects EUV light on one main surface of a substrate 11, and the multilayer reflective film 12 on the multilayer reflective film 12. Is a mask having a transfer pattern formed by providing at least an absorption layer 15 that absorbs EUV light, and having a conductive layer 17 formed on the other main surface of the substrate 11, to a transferred object such as a wafer. In order to define a transfer pattern forming area and prevent the EUV light from being irradiated to areas other than the transfer pattern forming area, a light shielding band 18 having a predetermined width is provided around the transfer pattern. In FIG. 3, similarly to FIG. 1, a region where a transfer pattern is formed as a field on a transfer object such as a wafer is defined as a transfer pattern region 21, and a surrounding light shielding region other than the transfer pattern forming region is a peripheral light shielding region 22. It is said. The light-shielding band 18 is provided in a region that is in the peripheral light-shielding region 22 and is subjected to multiple exposure during exposure. Further, the outer side of the light shielding band 18 can be shielded with a blade during exposure.
The light shielding band 18 constituting the reflective mask 30 of the present embodiment will be described in more detail.

(Shading zone)
The light shielding band 18 of the present embodiment is configured by a layer in which the multilayer reflective film 12 is irradiated with laser light to destroy the multilayer reflective film 12, and is on the same plane as the multilayer reflective film 12 on the substrate 11. The light-shielding band 18 has a reflectivity lower than that of the multilayer reflective film 12. Further, as shown in FIG. 3A, the absorption layer 15 above the light shielding band 18 formed on the substrate 11 is removed, and the surface of the light shielding band 18 is exposed. Therefore, as shown in FIG. 3B, which is a plan view seen from the pattern side, the presence of the light shielding band 18 can be easily confirmed. The width of the light shielding band 18 in the second embodiment is the same as that in the first embodiment. The light shielding band 18 in the present embodiment is configured by a layer in which the light shielding band 18 destroys the multilayer reflective film 12 by irradiating the multilayer reflective film 12 with laser light from the pattern side. If the light-shielding band 18 in this embodiment destroys the multilayer reflective film 12 by laser beam irradiation and makes it lower than the reflectance of the multilayer reflective film 12 with respect to EUV light similarly to said 1st Embodiment, It is not always necessary to make all layers of the multilayer reflective film 12 laminated in several tens of layers by laser light irradiation a layer that is destroyed.

  In the reflective mask 30 of the present embodiment, as shown in FIG. 3A, the conductive layer 17 is formed on the other main surface opposite to the mask pattern provided on one main surface of the substrate 11. However, the conductive layer 17 may not be provided.

  Other constituent elements used in addition to the light shielding film 18 constituting the reflective mask 30 of the present embodiment are the same as the contents described in the first embodiment, and a description thereof is omitted here.

According to the reflective mask for EUV exposure according to the second embodiment, since the light shielding band 18 is on the same plane as the multilayer reflective film 12, the influence of shadowing of exposure light is reduced. Since the side surface of the reflective film 12 is not exposed, the mask has excellent cleaning resistance, and the effect of suppressing exposure light leakage by improving the light shielding property of the overlapping portion of the transfer pattern field in the EUV exposure is obtained. A pattern can be obtained.
Next, the manufacturing method of the reflective mask for EUV exposure of this invention is demonstrated.

<Manufacturing method of reflective mask>
The reflective mask manufacturing method of the present invention is formed on at least one main surface of a substrate by providing at least a multilayer reflective film that reflects EUV light and an absorption layer that absorbs EUV light on the multilayer reflective film. A method of manufacturing a reflective mask for EUV exposure having a transfer pattern, which defines a transfer pattern formation area on a transfer target and prevents irradiation of EUV light to areas other than the transfer pattern formation area Therefore, when providing a light shielding band around the transfer pattern, the multilayer reflective film in the region where the light shielding band around the transfer pattern is formed is irradiated with laser light to destroy the multilayer reflective film, A light-shielding band is formed by a multilayer reflective film.

  According to the reflective mask manufacturing method of the present invention, unlike the reflective mask described in Patent Document 2, the process of forming the second absorption film and patterning it is unnecessary, or 40 layers are formed. The process of removing the multilayer reflective film by digging deeply into the multilayer reflective film is unnecessary, and it is easy to manufacture a reflective mask with a light-shielding band in a short time without complicating the processing method during mask fabrication. Is possible.

  Hereinafter, an embodiment of a manufacturing method of a reflective mask for EUV exposure according to the present invention will be described with reference to the drawings. In the following drawings, the same reference numerals are used to indicate the same parts and materials. In addition, since each component and material of the reflective mask in the manufacturing method of the present invention are the same as the contents described in the above reflective mask, description thereof is omitted.

  FIG. 4 is a schematic cross-sectional view showing an example of a manufacturing process of a reflective mask that is not provided with a light shielding band, and is a conventionally known manufacturing process of a reflective mask. This is a process that is a pre-process common to the embodiment and the second embodiment.

  First, a reflective mask blank 40 for EUV exposure is prepared (FIG. 4A). The reflective mask blank 40 includes at least a multilayer reflective film 12 that reflects EUV light on one main surface of the substrate 11, and an absorption layer 15 a that absorbs EUV light on the multilayer reflective film 12. It is said. In the reflective mask blank 40 shown in FIG. 4A, a capping layer 13 and a buffer layer 14a are further provided in this order on the multilayer reflective film 12, and an antireflection layer 16a is provided on the absorbing layer 15a. .

  Next, in order to pattern the absorption layer 15a, a resist pattern 19 is formed (FIG. 4B), and the antireflection layer 16a, the absorption layer 15a, and the buffer layer 14a are dry-etched in this order, and FIG. As shown in FIG. 2, a reflective mask 50 is produced. The reflective mask 50 is provided with at least a multilayer reflective film 12 that reflects EUV light on one main surface of the substrate 11 and an absorption layer 15 that absorbs EUV light on the multilayer reflective film 12 as a pattern forming layer. A transfer pattern region 21 and a peripheral light shielding region 22. The reflective mask 50 shown in FIG. 4C has a configuration in which a capping layer 13 and a buffer layer 14 are further provided in this order on the multilayer reflective film 12, and an antireflection layer 16 is provided on the absorption layer 15. ing.

  As described above, the reflective mask 50 and the manufacturing method thereof shown in FIG. 4C are known, and therefore the details of the manufacturing method of FIG. 4 are omitted. In the reflective mask manufacturing method of the present invention having a light shielding band shown in the first and second embodiments described below, the reflective mask 50 is formed by etching the absorption layer 15a to form a transfer pattern. It is characterized by forming a shading zone after fabrication.

1. First Embodiment FIG. 5 is a schematic cross-sectional view showing the manufacturing process of the first embodiment following FIG. 4 of the reflective mask of the present invention having the light shielding band shown in FIG. The reflective mask manufacturing method according to the present embodiment includes a multilayer reflective film around a transfer pattern from the other main surface side of the substrate through the substrate after first producing a reflective mask for EUV exposure without a light shielding band. The multilayer reflection film is destroyed by irradiating the laser beam, and a light shielding band is formed by the broken multilayer reflection film.

  As shown in FIG. 5A, the reflective mask 50 described in FIG. 4 is prepared. The reflective mask 50 is formed by providing, on one main surface of the substrate 11, at least a multilayer reflective film 12 that reflects EUV light and an absorption layer 15 that absorbs EUV light on the multilayer reflective film 12. It is a mask which has a pattern for use. In the reflective mask 50 shown in FIG. 5A, a capping layer 13 and a buffer layer 14 are sequentially provided on the multilayer reflective film 12, and an antireflection layer 16 is provided on the absorption layer 15.

  Next, as shown in FIG. 5B, the multilayer reflective film 12 is destroyed by irradiating the multilayer reflective film 12 with the laser beam 23 from the other main surface side opposite to the transfer pattern forming side of the substrate 11. . The broken multilayer reflective film 12 portion is formed as a light-shielding band 18 having a predetermined width that is low-reflective with respect to EUV light that defines a region for forming a pattern for transfer onto a transfer target. 10 is obtained.

  FIG. 5C is a schematic cross-sectional view of the reflective mask 10 of the present invention in which the light shielding band 18 is formed. The light shielding band 18 is on the same plane as the multilayer reflective film 12 on the substrate 11, and is sandwiched between the substrate 11, the capping layer 13, the buffer layer 14, and the absorption layer 15 to form the reflective mask 10. Built in.

  In EUV exposure, for example, a reflective film for EUV light is not a regular multilayer film, such as a multilayer reflective film formed by alternately stacking 40 layers of Mo of thickness 2.9 nm and Si of 4.0 nm. And EUV light cannot be reflected efficiently. On the other hand, as described in the reflective mask of the present invention, the multilayer reflective film 12 that reflects EUV light is weak against high heat, and the multilayer reflective film 12 is destroyed by the heat of laser light irradiation, and the reflectance with respect to EUV light decreases. . Therefore, if the temperature of the irradiated part is raised by laser light irradiation and the regularity of the heat-resistant multilayer film is destroyed by the thermal action, the reflectance of EUV light can be lowered. In the destruction of the multilayer reflective film 12 in the present invention, it is not always necessary to irradiate the multilayer reflective film 12 with a laser beam having such a high energy as to evaporate the multilayer reflective film 12 or form holes in the multilayer reflective film 12.

  In the present invention, it is unclear whether the multilayer reflective film 12 irradiated with the laser beam is melted and alloyed by heat, or whether Mo and Si form a diffusion layer or change to another structure. If the function as the reflection film is destroyed by the laser light irradiation and the laser light irradiation portion becomes a layer having a lower reflectance than the multilayer reflection film with respect to the EUV light, it can be used as a light shielding band. Therefore, the light shielding band 18 does not necessarily have to be destroyed all of the multilayer reflective film.

  A major feature of laser processing is that it is excellent in local processing using a spot beam diameter. While the width of the light-shielding band 18 is usually processed within a range of about 1 mm to 10 mm in a quadruple mask, the beam diameter of a general laser beam can be narrowed down to 20 μm to 30 μm. Therefore, the light shielding band can be produced by a simple process without damaging other than the light shielding band forming region.

Various lasers can be used as the laser that meets the purpose of causing a thermal action on the irradiated portion of the multilayer reflective film 12 and destroying it. However, when the substrate 11 is glass, for example, a laser is used. Examples of the light 23 include a CO ₂ laser, an Nd: YAG laser, an excimer laser, and a femtosecond laser. When the substrate 11 is silicon that does not transmit visible light or ultraviolet light, a CO ₂ laser that is an infrared laser is used. Also, by using a pulsed laser, it is possible to obtain pulsed light with a short time width of nanoseconds to femtoseconds, concentrating energy within the short time width, obtaining high output and shortening the processing time. be able to.

  In the present invention, although not shown, laser light oscillated by an oscillator is transmitted through an optical path, condensed to an appropriate size by a condenser lens 24, and irradiated to a multilayer reflective film of a reflective mask. By providing an XY drive system that can move the laser condensing point (processing point) at high speed, and installing a reflective mask and irradiating laser light, a rectangular track-shaped shading band can be easily formed around the transfer pattern. Can be formed.

  In the manufacturing method of the present embodiment, the multilayer reflection film 12 is broken by irradiating the laser beam 23 from the other main surface side of the substrate 11 through the substrate 11, and the light shielding band 18 is formed by the broken multilayer reflection film 12. Therefore, it is not necessary to newly form a light shielding band material, and further, a resist process and a dry etching process for providing a light shielding band region are unnecessary, and a light shielding band can be formed in a predetermined region by a simple process. Have advantages. Furthermore, the manufacturing method of a reflective mask for EUV exposure according to the present invention uses a reflection-type mask that has not been provided with a light-shielding region and forms a light-shielding band at a predetermined position of the mask. The reflective mask can be provided. In this embodiment, if a conductive layer is provided on the other main surface side of the substrate 11, a conductive layer may be formed on the other main surface side after the light shielding band shown in FIG. 5C is formed. .

2. Second Embodiment FIG. 6 is a schematic cross-sectional view showing a manufacturing process of a second embodiment of the reflective mask of the present invention having the light shielding band shown in FIG. The reflective mask manufacturing method according to the present embodiment is a method for forming a light-shielding band on one main surface of a substrate on which a transfer pattern is formed after producing a reflective mask for EUV exposure without a light-shielding band. A resist pattern is formed and the absorption layer is etched using the resist pattern as a mask to expose the multilayer reflective film in a region to be a light shielding zone. Next, the exposed multilayer reflective film is exposed from one main surface side of the substrate. The multilayer reflective film exposed by irradiating a laser beam is destroyed, and a light-shielding band is formed by the broken multilayer reflective film.

  As shown in FIG. 6A, a reflective mask 60 without a light shielding band is prepared. The reflective mask 60 is formed by providing, on one main surface of the substrate 11, at least a multilayer reflective film 12 that reflects EUV light and an absorption layer 15 that absorbs EUV light on the multilayer reflective film 12. This is a mask having a pattern for use and having a conductive layer 17 formed on the other main surface of the substrate 11. In the reflective mask 60 shown in FIG. 6A, the capping layer 13 and the buffer layer 14 are provided in this order on the multilayer reflective film 12, and the antireflection layer 16 is provided on the absorption layer 15. In the present embodiment, the reflective mask 60 can be manufactured by the same method as the manufacturing method shown in FIG.

  Next, as shown in FIG. 6B, a resist for forming a light shielding band is applied on one main surface of the substrate on which the transfer pattern is formed, exposed and developed, and then the light shielding band resist is formed. A pattern 25 is formed. Next, as shown in FIG. 6C, the resist pattern 25 is used as a mask, and the antireflection layer 16, the absorption layer 15, and the buffer layer 14 are etched in this order to form an opening 26, thereby forming a light shielding zone. The multilayer reflective film 12 is exposed. As shown in FIG. 6C, when the capping layer 12 is provided, the capping layer 12 may be removed by etching, or may be left as it is. Laser processing of the reflective film 12 is possible.

  Next, as shown in FIG. 6 (d), the exposed multilayer reflective film 12 is irradiated with laser light 23 from one main surface side of the substrate 11 to destroy the exposed multilayer reflective film 12. The broken multilayer reflective film 12 portion is formed as a light-shielding band 18 having a predetermined width that is low-reflective with respect to EUV light that defines a region for forming a pattern for transfer onto a transfer target. 30 is obtained.

  FIG. 6E is a schematic cross-sectional view of the reflective mask 30 of the present invention in which the light shielding band 18 is formed. The light shielding band 18 is formed of a layer in which the multilayer reflective film is irradiated with laser light to destroy the multilayer reflective film. The light shielding band 18 is on the same plane as the multilayer reflective film 12 on the substrate 11 and is formed on the substrate 11. The upper absorption layer 15 of 18 is removed, and the surface of the light shielding band 18 is exposed.

  In the manufacturing method according to the present embodiment, the multilayer reflective film 12 is exposed in a region where the light-absorbing layer 15 is etched by etching the absorption layer 15 using the resist pattern 25 formed on one main surface of the substrate 11 on which the transfer pattern is formed as a mask. Next, the exposed multilayer reflective film 12 is irradiated with the laser beam 23 from one main surface side of the substrate 11 to destroy the exposed multilayer reflective film 12, and the broken multilayer reflective film 12 blocks light. In order to form the band 18, there is no need to form a new light shielding band material or patterning, and the light shielding band can be formed in a predetermined region with a simple process. Further, even with a mask in which the conductive layer 17 is provided on the other main surface side of the substrate 11, a light shielding band can be formed. Furthermore, the manufacturing method of a reflective mask for EUV exposure according to the present invention uses a reflection-type mask that has not been provided with a light-shielding region and forms a light-shielding band at a predetermined position of the mask. The reflective mask can be provided.

3. Third Embodiment FIG. 7 is a schematic cross-sectional view showing a manufacturing process of a third embodiment in the manufacturing method of the reflective mask of the present invention having the light shielding band shown in FIG. The reflective mask manufacturing method of the present embodiment uses a reflective mask blank to form a transfer pattern and a resist pattern for forming a light-shielding band on an absorbent layer, and then uses the resist pattern as a mask to form an absorbent layer. Is etched to expose the multilayer reflective film, and then the laser beam is irradiated from the main surface side of the substrate on which the transfer pattern is formed to the light shielding zone of the multilayer reflective film that is exposed. The film is broken, and a light shielding band is formed by the broken multilayer reflective film.

  As shown in FIG. 7A, a reflective mask blank 40 without a light shielding band is prepared. The reflective mask blank 40 includes at least a multilayer reflective film 12 that reflects EUV light on one main surface of the substrate 11 and an absorption layer 15a that absorbs EUV light on the multilayer reflective film 12. 11 is a mask blank in which a conductive layer 17 is formed on the other main surface. In the reflective mask blank 40 shown in FIG. 7A, a capping layer 13 and a buffer layer 14a are further provided in this order on the multilayer reflective film 12, and an antireflection layer 16a is provided on the absorbing layer 15a. .

  Next, as shown in FIG. 7B, a resist for forming a transfer pattern and a light-shielding band is applied on one main surface of the substrate 11, exposed, developed, and transferred. And a light shielding band resist pattern 27 is formed. Next, as shown in FIG. 7C, using the resist pattern 27 as a mask, the antireflection layer 16, the absorption layer 15, and the buffer layer 14 are etched in this order to form a transfer pattern and an opening for a light shielding band. 26 is formed to expose the multilayer reflective film 12 in a region to be a light shielding zone. As shown in FIG. 7C, when the capping layer 13 is provided, the capping layer 13 may be removed by etching, or may be left as it is. Laser processing of the reflective film 12 is possible.

  Next, as shown in FIG. 7D, the exposed multilayer reflective film 12 is irradiated with laser light 23 from one main surface side of the substrate 11 to destroy the exposed multilayer reflective film 12. The broken multilayer reflective film 12 portion is formed as a light-shielding band 18 having a predetermined width that is low-reflective with respect to EUV light that defines a region for forming a pattern for transfer onto a transfer target. 30 is obtained.

  FIG. 7E is a schematic sectional view of the reflective mask 30 of the present invention in which the light shielding band 18 is formed. The light shielding band 18 is composed of a layer obtained by irradiating the multilayer reflective film with laser light and destroying the multilayer reflective film, and is on the same plane as the multilayer reflective film 12 on the substrate 11 and is formed on the substrate 11. The absorption layer 15 above the band 18 is removed, and the surface of the light shielding band 18 is exposed.

In the manufacturing method of the present embodiment, a pattern for forming a transfer pattern and a light shielding band is simultaneously formed on one main surface of the substrate 11, and the exposed multilayered reflection film 12 is used as a light shielding band. This is a method in which the multilayer reflective film 12 is destroyed by irradiating the laser beam 23, and the light shielding band 18 is formed by the broken multilayer reflective film 12, and it is not necessary to form a new light shielding band material or patterning, and it is simple. This has an advantage that a light shielding band can be formed in a predetermined region by a simple process. Further, even with a mask in which the conductive layer 17 is provided on the other main surface side of the substrate 11, a light shielding band can be formed. The manufacturing method of the present embodiment forms the transfer pattern and the light shielding band opening at the same time, so that the resist process may be performed in one step, and the process can be shortened as compared with the second embodiment. Have.
Hereinafter, the present invention will be described in more detail by way of examples.

Example 1
On one main surface (surface) of a 6-inch square (0.25-inch thick) optically polished synthetic quartz substrate, a Si magnet is used with a Si target in an Ar gas atmosphere by DC magnetron sputtering. A film was formed to 4.2 nm, then a Mo film was formed to 2.8 nm using a Mo target, and this was formed as one period, and then 40 periods were laminated. Finally, a Si film was formed to 11 nm to form a capping layer. A multilayer reflective film that reflects EUV light composed of a multilayer film of Mo and Si was formed.
Next, a CrN film having a thickness of 10 nm was formed on the multilayer reflective film by a DC magnetron sputtering method using a Cr target in a mixed gas atmosphere of Ar and nitrogen to form a buffer layer.
Subsequently, a TaBN film having a thickness of 80 nm is formed on the CrN film by a DC magnetron sputtering method using a target containing Ta and B in a mixed gas atmosphere of Ar and nitrogen. Thus, a reflective mask blank for EUV exposure having an absorption layer that absorbs UV was obtained.

Next, using this EUV exposure mask blank, an EB resist was applied, and EB drawing was performed to form a resist pattern. Next, the TaBN absorption layer is dry-etched with Cl ₂ gas, the CrN buffer layer is dry-etched with a mixed gas of Cl ₂ and oxygen, the resist pattern is stripped, and a multilayer reflective film provided with a capping layer Was exposed to obtain a reflective mask having a transfer pattern and no shading band.

  Next, from the other main surface (back surface) side of the quartz substrate facing the transfer pattern forming side of the reflective mask, a central wavelength of 800 nm is formed on the multilayer reflective film around the transfer pattern on which the light shielding band is to be formed. The multilayer reflective film was destroyed by irradiation with femtosecond laser light. The destroyed multilayer reflective film portion is formed as a light-shielding band having a rectangular track shape width of 5 mm and a low reflectivity with respect to EUV light that defines a formation area of a transfer pattern on a transfer target, and is incorporated in the mask. A reflective mask having a light shielding band was obtained.

  In the reflective mask having the light shielding band of this embodiment, the light shielding band is on the same plane as the multilayer reflective film on the quartz substrate, and the space between the quartz substrate and the absorption layer through the capping layer and the buffer layer is. The exposure field of one shot is 24 × 36 mm. When pattern exposure onto the wafer was performed using the reflective mask of this example, there was no problem due to multiple exposure at the field boundary, and a good resist pattern could be formed. In addition, the reflective mask of this example showed a high cleaning resistance equivalent to that of a mask having no light shielding band because the light shielding band was built in the mask.

(Example 2)
The same reflective mask blank as in Example 1 was used, and Cr was deposited as a conductive layer by sputtering to a thickness of 20 nm on the other main surface (back surface) of the blank to obtain a reflective mask blank with a conductive layer.

Next, using the above mask blanks, an EB resist was applied, and EB drawing was performed to form a resist pattern. Next, the TaBN absorption layer is dry-etched with Cl ₂ gas, the CrN buffer layer is dry-etched with a mixed gas of Cl ₂ and oxygen, the resist pattern is stripped, and a multilayer reflective film provided with a capping layer Was exposed to obtain a reflective mask having a transfer pattern and no shading band.

Next, using the reflective mask having no light shielding band, a resist for forming a light shielding band is applied on one main surface (front surface) of the substrate on which the transfer pattern is formed, exposed and developed. Then, a resist pattern of a light shielding band was formed. Next, using the resist pattern as a mask, the absorption layer is dry-etched in order with a Cl ₂ gas, and the buffer layer is sequentially mixed with a mixed gas of Cl ₂ and oxygen to form an opening for the light-shielding band. The multilayer reflective film was exposed.

Next, the exposed multilayer reflective film was irradiated with CO ₂ laser light from one main surface (front surface) side of the quartz substrate to destroy the exposed multilayer reflective film. The destroyed multilayer reflective film portion is formed as a light-shielding band having a width of 8 mm that is low-reflective with respect to the EUV light that defines the formation area of the pattern to be transferred to the transfer target, and a reflective mask having a light-shielding band is obtained. It was.

  In the reflective mask having a light shielding band of this example, the light shielding band is constituted by a layer in which the multilayer reflective film is irradiated with laser light to destroy the multilayer reflective film, and is on the same plane as the multilayer reflective film on the quartz substrate. Yes, the absorption layer on the upper part of the light shielding band formed on the quartz substrate is removed, the surface of the light shielding band is exposed, and in pattern exposure on the wafer using the reflective mask of this embodiment, There was no problem due to multiple exposure at the field boundary, and a good resist pattern could be formed. In addition, the reflective mask of this example showed high cleaning resistance because the light shielding band and the side surfaces of the reflective film were not exposed.

(Example 3)
The same reflective mask blanks with the same conductive layer as used in Example 2 were prepared, and a resist for forming a transfer pattern and a light shielding band was applied on one main surface (surface) of the quartz substrate. Then, exposure and development were performed to form a resist pattern of a transfer pattern and a light shielding band. Next, using the resist pattern as a mask, the absorption layer is dry-etched in order with a Cl ₂ gas and the buffer layer is a mixed gas of Cl ₂ and oxygen to form a transfer pattern and an opening for a light-shielding band, The multilayer reflective film in the region to be the light shielding band was exposed.

Next, the exposed multilayer reflective film was irradiated with CO ₂ laser light from one main surface (front surface) side of the quartz substrate to destroy the exposed multilayer reflective film. The destroyed multilayer reflective film portion is formed as a light-shielding band having a width of 8 mm that is low-reflective with respect to the EUV light that defines the formation area of the pattern to be transferred to the transfer target, and a reflective mask having a light-shielding band is obtained. It was.

  In the reflective mask having a light shielding band of this example, the light shielding band is constituted by a layer in which the multilayer reflective film is irradiated with laser light to destroy the multilayer reflective film, and is on the same plane as the multilayer reflective film on the quartz substrate. Yes, the absorption layer on the upper part of the light shielding band formed on the quartz substrate is removed, the surface of the light shielding band is exposed, and in pattern exposure on the wafer using the reflective mask of this embodiment, There was no problem due to multiple exposure at the field boundary, and a good resist pattern could be formed. Further, the reflective mask of this example showed high cleaning resistance.

10, 20, 30 Reflective mask 11 having light-shielding band Substrate 12 Multi-layer reflective film 13 Capping layer 14 Buffer layer 14a Buffer layer (before patterning)
15 Absorbing layer 15a Absorbing layer (before patterning)
16 Antireflection layer 16a Antireflection layer (before patterning)
17 Conductive layer 18 Light shielding band 21 Transfer pattern area 22 Peripheral light shielding area 23 Laser light 24 Condensing lens 25 Resist pattern 26 Opening 40, 70 Reflective mask blanks 50, 60 Reflective mask (no light shielding band)
80 Reflective mask for EUV exposure 81 EUV light 82 Blade 83 Wafer 84 Field 85 Transfer pattern 86 Field overlap portion 101 Low expansion coefficient substrate 102 Multilayer reflective film 103 Protective film 104 Buffer layer 105 First absorption film 106 Second absorption film 107 Transfer Pattern Area 108 Light-shielding Area 110 Reflective Mask 111 Substrate 112 Multilayer Reflective Film 113 Capping Layer 114 Buffer Layer 115 Absorbing Layer 116 Antireflection Layer

Claims (7)

For EUV exposure having a transfer pattern formed by providing at least a multilayer reflective film that reflects EUV light and an absorption layer that absorbs EUV light on the multilayer reflective film on one main surface of the substrate. A reflective mask,
A light shielding band is provided around the transfer pattern to define a transfer pattern formation area on the transfer target and to prevent irradiation of the EUV light to areas other than the transfer pattern formation area. And
The light shielding band is configured by a layer in which the multilayer reflective film is irradiated with laser light to destroy the multilayer reflective film, and is on the same plane as the multilayer reflective film on the substrate, and the light shielding band for the EUV light The reflective mask is characterized in that the reflectance is lower than the reflectance of the multilayer reflective film.   The reflective mask according to claim 1, wherein the light shielding band is sandwiched between the substrate and the absorption layer and is built in the reflective mask.   2. The reflective mask according to claim 1, wherein the absorption layer on the light shielding band formed on the substrate is removed, and a surface of the light shielding band is exposed. For EUV exposure having a transfer pattern formed by providing at least a multilayer reflective film that reflects EUV light and an absorption layer that absorbs EUV light on the multilayer reflective film on one main surface of the substrate. A method of manufacturing a reflective mask,
In defining a transfer pattern forming area on the transfer target and preventing irradiation of the EUV light to areas other than the transfer pattern forming area, when providing a light shielding band around the transfer pattern,
A method of manufacturing a reflective mask, comprising: irradiating the multilayer reflective film around the transfer pattern with laser light to destroy the multilayer reflective film, and forming the light-shielding band with the destroyed multilayer reflective film . In the manufacturing method of the reflective mask according to claim 4, after producing the reflective mask for EUV exposure without the shading band,
The multilayer reflective film around the transfer pattern is irradiated with laser light from the other main surface side of the substrate through the substrate to destroy the multilayer reflective film, and the light shielding band is broken by the broken multilayer reflective film. Forming a reflective mask. In the manufacturing method of the reflective mask according to claim 4, after producing the reflective mask for EUV exposure without the shading band,
The resist pattern for forming the light shielding band is formed on one main surface of the substrate on which the transfer pattern is formed, and the absorbing layer is etched using the resist pattern as a mask to form the light shielding band Exposing the multilayer reflective film of
Next, the exposed multilayer reflective film is irradiated with laser light from one main surface side of the substrate to destroy the exposed multilayer reflective film, and the shading band is formed by the destroyed multilayer reflective film A method for producing a reflective mask, comprising: 5. The method of manufacturing a reflective mask according to claim 4, wherein a resist pattern for forming the transfer pattern and the light shielding band is formed on the absorbing layer using a reflective mask blank, and the resist pattern is formed. Etching the absorbing layer using as a mask to expose the multilayer reflective film,
Next, from one main surface side of the substrate on which the transfer pattern is formed, the exposed area of the multilayer reflective film as a light shielding zone is irradiated with laser light to destroy the multilayer reflective film, A method of manufacturing a reflective mask, wherein the light shielding band is formed by a broken multilayer reflective film.

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