JPH09326355A - Deposition of thin film with support and production of x-ray mask - Google Patents

Abstract

PROBLEM TO BE SOLVED: To deposit a thin film secured to a support and to produce an X-ray mask while protecting them against mechanical damage and eliminating contamination due to acid or alkali. SOLUTION: A substance making a transition to a liquid phase or a solid phase at a temperature lower than the denaturation point of a thin film substance is employed as a basic material 12. A thin film 13 is then deposited thereon to form a laminate 14 which is then brought into tight contact with a support 11 composed of a substance in which phase transition does not take place at a temperature lower than the transition temperature of the basic material 12. Subsequently, it is heat treated at a temperature higher than the transition temperature of the basic material 12 but lower than the denaturation point of the thin film substance to produce a thin film 10 with support. An X-ray absorber is then bonded onto the thin film 10 with support and sputtered to produce an X-ray mask.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a thin film with a support, which is used as various device materials, sensor materials, optical thin film materials, X-ray mask membrane materials, and structural materials, and more particularly to a method for supporting on a substrate Thin films, especially silicon carbide thin films and diamond thin films,
The present invention relates to a forming method capable of functionally and effectively removing a substrate portion according to a purpose and improving yield. Also,
In particular, the present invention relates to a manufacturing method capable of suppressing the occurrence of contamination and mass-producing an X-ray mask using a silicon carbide permeable film by an atmospheric dry process.

[0002]

2. Description of the Related Art Silicon carbide (SiC), diamond,
Materials such as carbon such as graphite, which are thermally and chemically stable and have excellent mechanical strength, have been applied to applications such as structural materials and environment resistant materials. In particular, since silicon carbide and diamond also have the property that they are semiconductor materials with a wider band gap than silicon, etc., they are used not only for environment-resistant elements and power elements but also for various semiconductor device materials, sensor materials, and for manufacturing these. Is also attracting attention as a material for microfabrication. By treating these materials as a thin film, the material characteristics can be remarkably utilized. That is, the invention is applied to a thin film device structure utilizing semiconductor characteristics, a diaphragm structure utilizing mechanical characteristics of a thin film, and a light transmitting film represented by an X-ray membrane utilizing optical characteristics. Therefore, various thin film manufacturing methods for obtaining thin films of these materials have been developed.

As a method of producing a thin film, particularly a thin film of silicon carbide or diamond, deposition on a substrate is generally used. Examples of the deposition method include a chemical vapor deposition method (CVD method) using heat, light and plasma, a molecular beam epitaxy method, a sputtering method and the like. For example, if such a deposition method is used to form a silicon carbide thin film, a silicon carbide thin film having a large area can be obtained by using a large substrate, and a combination of a base material and a deposition substance or deposition conditions can be used to obtain a single amorphous structure. It is effective in that an arbitrary structure can be obtained up to the crystal structure. For example, JP-A-7-11
In 8854, a silicon substrate or the like is used as a base substrate, and a silicon compound generated by thermally decomposing a silicon source gas in a state where hydrogen gas is substantially absent is adsorbed on a growth surface on the substrate, and this silicon compound is A method of producing a single crystal silicon carbide thin film on a substrate by carbonizing a carbon source gas to generate silicon carbide with high mass productivity is disclosed.

Regarding the method for producing silicon carbide, in addition to the deposition method, there is a sublimation method as a method capable of ingot growth. However, this method requires a high temperature near 2000 ° C. and obtains a large-area thin film. The problem that it is difficult to produce a large-diameter ingot required for this, in that it is necessary to process by cutting to make a thin film,
Its application range and mass productivity are largely limited, and there are obstacles to its practical application as a thin film forming method.

When using silicon carbide or diamond as the thin film, in many cases, the thin film formed by depositing silicon carbide on the substrate or the substrate by the above-mentioned deposition method is treated and treated. The thickness of the thin film depends on the purpose of use, but is generally in the range of several hundred Å to several tens of μm. As an example of handling a silicon carbide thin film formed on a silicon substrate, Japanese Unexamined Patent Publication No. 7-335562 discloses that a single crystal silicon substrate surface is carbonized to form a single crystal silicon carbide layer, and the silicon carbide layer is separated from the silicon substrate. In addition, a method for obtaining a silicon carbide film having a large area and excellent crystallinity by again depositing silicon carbide using the silicon carbide layer as a substrate is disclosed. Further, in JP-A-2-262324, internal stress control is characterized in that a thin film is formed on a substrate by reacting silicon and carbon at a specific ratio under a reduced pressure by a CVD method using a hot wall method. The manufacturing process and the membrane structure of an X-ray mask membrane composed of a thin film containing silicon carbide, which has excellent properties, X-ray irradiation resistance, and surface smoothness, are disclosed.

[0006]

In order to use a deposited film or grown film of silicon carbide or diamond formed on a substrate by a conventional technique as a thin film material, the underlying substrate is removed and the thin film itself is self-supporting. In addition, it is often necessary to provide a thin film support to facilitate handling. Such a requirement arises, for example, from a thin film formed, a device utilizing its semiconductor characteristics,
This is a case of using as a diaphragm structure utilizing the strength of a thin film, or as an X-ray membrane or light transmitting film utilizing optical characteristics.

As a method of removing the substrate, there are a method of chemically or physically etching an appropriate portion of the substrate, a method of mechanically cutting the substrate. As a chemical method,
Typical examples are wet etching in which a substrate is chemically dissolved, and dry etching represented by reactive ion etching. However, in the case of wet etching, mechanical damage is likely to occur when handling the silicon carbide thin film portion,
There are problems that contamination is likely to occur during work, that dangerous acids and alkalis are used, and that waste solutions of these acids and alkalis must be treated. On the other hand, in the case of dry etching, the etching rate is extremely slow compared with wet etching or mechanical removal, so that there is a problem that mass productivity cannot be obtained when the thickness of the substrate exceeds several tens of μm. Further, regarding the method of mechanically removing the substrate such as cutting, the problem of damage to the object and the problem of processing accuracy remain unsolved.

Further, since the thin film separated from the substrate is extremely thin and difficult to handle, it is not easy to fix the thin film to the support later to form an integrated structure, and much more difficult to mass-produce industrially. It was Further, as a method for manufacturing an X-ray mask using a thin film as an X-ray transparent film, a wet etching method using an acid is generally used, but it is difficult to avoid contamination during the process.

Therefore, the problem to be solved by the present invention is to separate the substrate from the thin film more easily, without the need for treatment with acid or alkali, contamination of the thin film, and mechanical damage. Another object of the present invention is to provide a method for forming a thin film with a support, in which a thin film is attached to a support and fixed to form an integral structure. A second problem to be solved by the present invention is to provide a stable manufacturing process capable of mass-producing X-ray masks with suppressed contamination.

[0010]

In order to solve the above problems, a method for forming a thin film with a support according to the present invention for obtaining a thin film supported by a support is as follows. First, a liquid is formed at a temperature lower than a transformation temperature of a substance forming the thin film. A thin film is deposited on a substrate made of a material that transforms into a phase or a gas phase to form a laminate, and then the above-formed laminate is adhered to a support made of a substance that does not undergo phase conversion at the transformation temperature of the substrate. After forming the composite, the method is characterized by including a step of removing the base by subjecting the composite to a heat treatment at a temperature not lower than the transformation temperature of the substrate and lower than the thin film transformation temperature.

It is particularly preferable that the thin film and the support are chemically bonded at the interface by heat treatment of the composite. Further, the material forming the thin film may be silicon carbide or carbon, and the substrate may be silicon. Also,
A thermal CVD method may be used as a method for depositing a thin film on a substrate. Further, the heat treatment of the composite is preferably performed in an atmosphere containing at least one of hydrogen, oxygen, chlorine and fluorine, and also containing at least one of helium, neon, argon, xenon and nitrogen. It can also be performed in an atmosphere or in a vacuum.

In order to solve the second problem, the X-ray mask manufacturing method of the present invention is made of silicon in the step of obtaining an X-ray transparent film made of silicon carbide whose peripheral portion is supported by a support frame. A silicon carbide thin film is deposited on a substrate to form a laminated body, and then the laminated body is brought into close contact with a supporting frame that supports the peripheral portion of the thin film, and then at a temperature not lower than the transformation temperature of silicon and lower than the transformation temperature of silicon carbide. The method is characterized by including a step of removing the substrate by heat treatment.

According to the method for forming a thin film with a support of the present invention,
A substrate made of a material that transforms to a liquid phase or a gas phase at a temperature lower than the transformation temperature of a substance forming a thin film and a support made of a substance that maintains a solid phase without phase conversion at the transformation temperature of the substrate are appropriately selected, After forming a composite by adhering a laminate formed by depositing a thin film on the substrate to a support,
Next, the formed composite is heat-treated at a temperature not lower than the transformation temperature of the substrate and lower than the thin film transformation temperature. Therefore, in the heat treatment step, while the thin film and the support maintain the solid phase, only the substrate is liquefied or vaporized and removed, and the free-standing thin film remains supported by the support, so that the characteristics of the thin film are utilized. A useful thin film body can be obtained.

Further, since the thin film is brought into close contact with the support in the state of the laminated body formed on the substrate, the handling becomes much easier as compared with the case where only the thin film is handled. Further, since the area of the thin film increases as the area of the base increases, it becomes possible to easily obtain a large thin film with a support. According to the method of the present invention, the shape of the support is not limited to the shape of the base, and the step of removing the base and the step of producing an integrated structure composed of the thin film and the support can be performed at the same time.
It is possible to obtain special effects such as selection of an appropriate support material without being restricted by the substrate used initially. Therefore, it is also effective for producing a diaphragm structure or a membrane structure in which a silicon carbide thin film or a thin film made of carbon is stretched like a drum to have a void portion on the back side of the thin film. Further, the method of the present invention, without the use of chemical agents and without mechanical treatment,
By utilizing the difference in the phase transformation temperature of the raw material, it is removed by melting or sublimating or evaporating only the base portion by heat treatment, so there is no contamination due to the residual acid or alkali in the thin film, It is suitable for industrial production because there is no risk of mechanical finishing on the surface of the thin film and the number of steps is small.

The support used in the present invention may be any material that does not melt, evaporate or sublime at the substrate removal temperature, but it forms a chemical bond at the interface between the thin film such as silicon carbide and the support by heat treatment. It is more desirable if the interface is stabilized. Therefore, for example, when the thin film is silicon carbide, it is desirable to use a substance that reacts with silicon or carbon of silicon carbide in the thin film to produce a compound such as silicon carbide or silicide. Examples of such substances include graphite, diamond, silicon carbide, titanium, vanadium, chromium, cobalt, nickel, iron, zirconium, niobium, molybdenum, palladium, hafnium, tantalum, tungsten, iridium, platinum, etc. Can be a material containing at least one selected from these substances. As described above, by appropriately selecting the materials of the thin film and the support, it is possible to chemically bond the thin film and the support at the interface by heat treatment, but in such a case, After the substrate is removed, an integral structure is obtained in which the thin film is held in close contact with the support.

In the composite before heat treatment, the thin film and the support may be in direct contact with each other, or the substrate may be interposed therebetween. That is, when the thin film surface is superposed on the support, the substrate portion can be thermally removed, and at the same time, the thin film and the support can be bonded to each other by advancing the bonding therebetween. Also, when heat-treating the substrate side of the thin film deposition substrate to the support, the substrate and the support are initially in contact with each other, but as the substrate is removed by heating, the thickness of the substrate becomes thin, and as a result, Leads to the formation of a contact interface between the thin film and the support. Therefore, as long as the substrate is not extremely thick, the same thin film with a support can be obtained even if the thin film surface of the thin film deposition substrate is superposed on the support or the substrate side is superposed. Further, if the conditions are selected, it is possible to shorten the process by performing the heat treatment for chemically bonding the thin film and the support together with the heat treatment for removing the substrate. In addition, instead of heating the entire substrate by removing the substrate by heat treatment, if a device capable of locally heating, such as a concentrating lamp heating device, is used, only a predetermined area of a part of the substrate is covered. It can be removed to some extent.

When the material forming the thin film is silicon carbide or carbon and the substrate is silicon, the lattice constant and the coefficient of thermal expansion of the thin film and the substrate are close to each other, so that a thin film with good crystallinity can be obtained and It is possible to provide a material that makes full use of a useful thin film having dynamic strength and semiconductor properties. Here, as the thin film made of carbon, there is a diamond thin film or the like for which attention is paid to strength and semiconductor properties. According to the forming method of the present invention, not only a diamond single crystal but also a carbon thin film such as amorphous carbon or graphite can be freely formed by appropriately selecting the conditions for depositing a thin film on a silicon substrate. I can. Further, by using the thermal CVD method as a method for depositing a thin film on a substrate, a desired thin film can be easily obtained by fully utilizing the established technology.

The temperature at which the substrate is substantially thermally removed depends on the transformation temperature and the heat resistant temperature of the materials used for the substrate and the support, but is 20 when silicon is used as the substrate.
It may be set to an appropriate value of 00 ° C or lower. The heat treatment temperature is preferably 1700 ° C. or lower, and more preferably 1500 ° C. or lower.

Further, it is effective to use a silicon substrate as a substrate for depositing the silicon carbide thin film. The silicon substrate can be easily removed by melting, vaporizing or sublimating in the temperature range of 1400 ° C to 1500 ° C. Furthermore, by using a silicon substrate, it is possible to obtain a high-quality silicon carbide thin film in any of amorphous, polycrystalline, and single crystal structures. In addition, since it is easy to increase the area of the silicon carbide thin film by selecting the substrate dimensions, and it is easy to obtain a high-quality silicon substrate, etc., in terms of industrial mass productivity, yield, etc., in carrying out this process. Very high effect can be expected.

By performing the heat treatment of the composite in an atmosphere containing at least one of hydrogen, oxygen, chlorine, and fluorine, it becomes possible to chemically change the substrate and accelerate the removal of the substrate. Furthermore, when the heat treatment is performed in an atmosphere containing at least one of helium, neon, argon, xenon, and nitrogen, the thermal conductivity can be improved and the phase transformation and the chemical reaction can be promoted. Also, the method of controlling the surface state by performing heat treatment in vacuum can be expected to have particular effects such as an increase in evaporation rate and thermal sublimation rate.

According to the method for manufacturing an X-ray mask of the present invention, a silicon carbide thin film is deposited on a substrate made of silicon to form a laminated body, and then the laminated body is supported on the peripheral portion of the thin film. After being adhered to the substrate, the substrate is removed by heat treatment at a temperature not lower than the transformation temperature of silicon and lower than the transformation temperature of silicon carbide. A membrane can be obtained.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to the drawings based on embodiments.

[0023]

Example 1 FIG. 1 is a sectional view of a material in each step for explaining a manufacturing process of a silicon carbide thin film in Example 1. In this example, a silicon carbide thin film on graphite was obtained by using a laminate obtained by depositing silicon carbide on a substrate of a silicon wafer and a support made of high-purity graphite. 1A is a perspective view of a support used in Example 1, FIG. 1B is a cross-sectional view of a laminated body, and FIG. 1C is a cross-sectional view showing a state where the support and the laminated body are superposed. , Figure 1
(D) is a cross-sectional view showing the silicon carbide thin film integrated structure on graffiti obtained in Example 1.

In this embodiment, the support 11 is shown in FIG.
An annular graphite as shown in (a) was used. The graphite support 11 has an outer diameter of 76 mm (3 inches),
The inner diameter was 51 mm (2 inches) and the thickness was 1 mm. As the laminated body, as shown in FIG. 1B, a laminated body 14 having a structure in which a silicon carbide thin film 13 was deposited on one surface of a silicon wafer 12 was used. Laminate 14
Was manufactured by the following method. That is, the thickness is 0.38 mm, the diameter is 76 mm (3 inches), and the plane orientation S is
Silicon carbide was deposited on a silicon wafer of i (100) by using a hot wall type low pressure vapor deposition method. At that time, the flow rate of the acetylene gas as the source gas was set to 10 SCC.
M, the flow rate of dichlorosilane gas was 10 SCCM, the flow rate of hydrogen gas was 100 SCCM, the pressure in the growth furnace was 1 to 100 mTorr, and the growth temperature was 1020 ° C. under the deposition conditions.

Next, the laminate 14 and the graphite support 1
As shown in FIG. 1 (c), 1 was placed on the silicon carbide thin film surface 13 side of the laminated body 14 and the support 11 so as to face each other and closely adhered to each other. In (helium flow), heating was performed at 1450 ° C. for 40 minutes. By this heat treatment, the silicon substrate 12 is completely removed, the interface between the silicon carbide thin film surface 13 and the graphite support 11 is well adhered, and as shown in FIG. It was possible to easily obtain the integrated structure 10 in which the silicon thin film 13 was supported.

FIG. 2 is a cross-sectional view showing a state where the superposing surfaces of the graphite support and the laminate are changed in the step of FIG. 1 (c). As shown in FIG.
It was confirmed that even when the side was brought into contact with the graphite support 21, the same effect as when the surface of the silicon carbide thin film 23 was brought into contact was obtained. Although not explicitly shown in this embodiment, the adhesion between the superposed surfaces of the substrate and the support may be improved by, for example, applying a load. Also, the atmosphere during heating is not particularly limited to argon and helium, and may be neon, xenon, nitrogen or the like.

[0027]

[Embodiment 2] FIG. 3 is a sectional view of a material in each step for explaining a manufacturing process of a silicon carbide thin film in the embodiment 2. In this example, a silicon carbide on molybdenum thin film was obtained by using a laminated body obtained by depositing silicon carbide on a substrate of a silicon wafer and a support made of molybdenum.
3 (a) is a perspective view of the support used in Example 2, FIG.
3B is a cross-sectional view of the laminated body, FIG. 3C is a cross-sectional view showing a state where the support and the laminated body are superposed, and FIG. 3D is an integrated silicon carbide thin film on molybdenum obtained in Example 2. It is sectional drawing showing a structure.

As the support, a square molybdenum flat plate having a large number of through holes as shown in FIG. 3A was used. The molybdenum support 31 has a size of 20 mm × 20 mm and a thickness of 5 mm.
A plurality of through holes 32 each having a size of about 2 mm and a diameter of 2 mm are arranged in the plane. As shown in FIG. 3B, the laminated body was formed as a laminated body 35 in which the silicon carbide thin film 34 was deposited on one surface of the silicon wafer 33 in the same manner as in Example 1. As shown in FIG. 3C, after the silicon carbide thin film surface 34 side of the laminated body 35 and the molybdenum support 31 are overlapped and brought into close contact with each other, the laminated body 35 is placed in an infrared lamp heating furnace as in Example 1. Then, heating was performed at 1450 ° C. for 30 minutes in a vacuum of about 5 × 10 ⁻³ Torr.

By this heat treatment, the silicon substrate 33 is completely removed, and the interface between the silicon carbide thin film surface 34 and the molybdenum support 31 is closely adhered to the molybdenum support 31 as shown in FIG. 3 (d). The integrated structure 30 including the silicon carbide thin film 34 could be easily obtained. Further, in the manufactured integrated structure 30, the thin film 34 is formed in the support through-hole 32.
It was possible to easily achieve a self-supporting diaphragm structure. Also in this embodiment, similar to the first embodiment, the same effect can be obtained even if the silicon substrate 33 side of the laminated body 35 and the support 31 are superposed so as to face each other. Such a diaphragm structure is a structure that is preferably used in the production of various sensors and devices. Therefore, by using this method, it is possible to provide a diaphragm structure with an arbitrary shape and high mass productivity. became.

[0030]

Example 3 In this example, a diamond thin film on graphite was obtained by using a laminate obtained by depositing diamond on a substrate of a silicon wafer and a support made of high-purity graphite. The main difference from Example 2 is that a diamond thin film is formed instead of the silicon carbide thin film.

The substrate used in Example 4 had a diameter of 76 mm.
(3 inches), thickness 0.38 mm, surface direction Si (10
A silicon wafer of 0), and a diamond thin film was deposited on a silicon substrate using a microwave plasma excited chemical vapor deposition apparatus. The diamond thin film deposition conditions in the microwave plasma-excited chemical vapor deposition apparatus are as follows.
CCM was used, the pressure in the growth furnace was 12 to 15 Torr, the growth temperature was 800 ° C., the output of the 2.45 GHz microwave was 500 W, and the diamond was grown for the required time. Through this step, a thin film deposition substrate in which diamond thin films having a thickness of 2 μm were laminated was obtained.

In this example, a diamond thin film on graphite was produced using the diamond thin film deposition substrate obtained as described above and a support made of high-purity graphite. The graphite support is a square flat plate having a size of about 20 mm × 20 mm and a thickness of about 5 mm, as in the case of Example 3, and a plurality of through holes having a diameter of 2 mm are arranged in the plane. After the diamond thin film surface of the diamond thin film deposition substrate and the graphite support were superposed and brought into close contact with each other, they were placed in an infrared lamp heating furnace in the same manner as in Example 1 and placed in a vacuum of about 5 × 10 ⁻³ Torr. In, heating was performed at 1450 ° C. for 30 minutes.

By this heat treatment, the silicon substrate was completely removed, and an integrated structure in which the diamond thin film was present on the graphite support could be easily obtained. Furthermore, with the produced integrated structure, it was possible to easily achieve a diaphragm structure in which the diamond thin film was self-supporting in the through hole of the support.

[0034]

Fourth Embodiment FIG. 4 is a sectional view of a material in each step for explaining the manufacturing process of the X-ray mask membrane in the fourth embodiment, and FIG. 5 is a sectional view for explaining the manufacturing process of the X-ray mask in the same embodiment. It is sectional drawing of the material in each process.
In this example, an X-ray mask membrane and an X-ray mask were produced using the silicon carbide thin film deposition substrate produced in the same manner as the above example. FIG. 4A is a sectional view of a silicon thin film deposition substrate for producing an X-ray mask membrane used in Example 4, FIG. 4B is a sectional view of a laminate, and FIG. 4C is a perspective view of a support. 4 (d) is a cross-sectional view showing a state where the support and the laminated body are superposed, and FIG. 4 (e) is a cross-sectional view of the X-ray mask membrane obtained in Example 4. Also, FIG.
FIG. 5A is a cross-sectional view of the X-ray mask membrane used for manufacturing the X-ray mask used in Example 4, and FIG.
FIG. 5C is a sectional view of the X-ray mask blank formed in the middle of Example 4, and FIG. 5D is a patterning of the resist on the X-ray mask blank. FIG. 5E is a sectional view of the applied state, and FIG. 5E is a sectional view of the X-ray mask obtained in Example 4.

For a silicon carbide thin film which is a substantial X-ray transparent film, a silicon wafer (Si (100) surface, diameter 76 mm (3 inches), thickness 0.38 mm) is used as a base substrate.
In the hot wall type reduced pressure vapor deposition method, dichlorosilane and acetylene are used as the source gas to deposit the silicon carbide thin film 42 on the entire surface of the silicon wafer 41 as shown in FIG. Was obtained as. After that, a laminated body structure 43 in which a silicon carbide thin film 42 is formed on one side surface of a silicon wafer 41 as shown in FIG. As the silicon carbide thin film support in this example, the frame structure 44 made of high-purity graphite as shown in FIG. 4C was used. The graphite support 44 is a disc having an outer diameter of 76 mm (3 inches) and a thickness of 2 mm, and the center of the plane is 25 m.
An m × 25 mm square window or hollow hole 45 is provided.

As shown in FIG. 4D, after the silicon carbide thin film surface 42 side of the laminated body 43 which is a silicon carbide thin film deposition substrate and the graphite support frame 44 are superposed, the infrared lamp heating is carried out as in the first embodiment. It was placed in a furnace and heated at 1450 ° C. for 60 minutes in an argon atmosphere (atmospheric pressure). As a result, the silicon substrate 41 is completely removed by the heat treatment, and as shown in FIG.
X having a monolithic structure in which the silicon carbide thin film 42 stands on
The line mask membrane structure 40 could be easily obtained. Regarding the superposition of the graphite support frame 44 and the silicon carbide thin film deposition substrate 43, the same effect can be obtained even if the silicon substrate 41 side and the graphite support frame 44 are brought into contact with each other, as illustrated in the first embodiment.

The X-ray mask is produced by the X-ray mask membrane 40 obtained in the above steps as shown in FIG.
Was carried out using First, as shown in FIG. 5B, X
An X-ray absorber such as T is formed on the line mask membrane 40.
A film 46 made of tantalum and boron such as a ₄ B is formed to a film thickness of 0.5 by RF magnetron sputtering using Ar gas.
It was made to be μm. Next, as shown in FIG. 5C, an electron beam resist 47 was applied on the X-ray absorber film 46 by a spin coat method to prepare an X-ray mask blank. Next in FIG.
As shown in (d), a design value of 0.
The resist 47 was patterned by performing electron beam writing in a line and space of 5 μm and subsequently performing wet development.

Further, with the resist pattern 48 as a mask, the absorber layer 46 was patterned by using chlorine gas as an etching gas in an ECR (Electron CycIotron Resonance) etching apparatus. As a result,
The X-ray mask 50 in which the desired pattern 49 made of the X-ray absorber 46 is arranged on the X-ray membrane 42 can be easily manufactured. By applying the method of the present invention, it becomes easy to achieve a structure in which the silicon carbide thin film 42, which is an X-ray transparent film, directly exists on the support frame 44. As described above, in the present invention, since the handling support frame is provided simultaneously with the production of the membrane, the step of providing the handling support frame, which is usually required in the production of the X-ray mask 50, can be omitted, and the X-rays can be omitted. It became easy to simplify the manufacturing process of the mask blank and the X-ray mask.

In the conventional X-ray mask manufacturing process, the wet etching method using acid is mainly used in the process of forming the substrate opening for manufacturing the mask membrane. Therefore, there are still problems such as occurrence of contamination during the X-ray mask manufacturing process and poor process reproducibility. In the manufacturing process of the X-ray mask by the method of the present invention, it is possible to dry the process because the wet etching method is not used, the above problems are solved, the occurrence of contamination is suppressed, and the stability of the mass production process is improved. Can be improved. In addition, reducing harmful waste liquids such as acids and alkalis can also contribute to solving environmental problems.
The step of producing an X-ray mask from the X-ray mask membrane is not limited to the method shown in Example 5, and a known method such as the step described in JP-A-6-112107 can be used as appropriate. It can be used.

[0040]

As described in detail above, the thin film made of silicon carbide or carbon formed on the substrate is separated from the substrate by thermally treating the substrate and removing it by melting or sublimation. The thin film can be easily obtained. In addition, when removing the substrate, by providing a support made of a material that does not melt or sublimate thermally, it is easy to obtain an integral structure consisting of a thin film and an appropriate support as it is when the substrate is removed, such as a diaphragm structure or a membrane structure. Came to be. Such an integrated structure is particularly suitable for use in various devices, sensors, optical thin films, and the like that take advantage of the characteristics of silicon carbide. Among them, the X-ray mask membrane and the structural material effective in X-ray mask fabrication are It can now be easily provided with high mass productivity.

[Brief description of drawings]

FIG. 1 is a drawing explaining a manufacturing process of a silicon carbide thin film in Example 1 of the present invention.

FIG. 2 is a cross-sectional view showing another superposition relationship between a graphite support and a laminate in the process of Example 1.

FIG. 3 is a diagram illustrating a manufacturing process of a silicon carbide thin film according to a second embodiment of the present invention.

FIG. 4 is a diagram illustrating a manufacturing process of an X-ray mask membrane according to a fourth embodiment of the present invention.

FIG. 5 is a diagram illustrating an X-ray mask manufacturing process according to a fourth embodiment.

[Explanation of symbols]

 10 monolithic structure 11 support 12 silicon wafer 13 silicon carbide thin film 14 laminated body 21 support 22 silicon wafer 23 silicon carbide thin film 30 monolithic structure 31 molybdenum support 32 through hole 33 silicon wafer 34 silicon carbide thin film 35 laminated body 40 X-ray mask Membrane structure 41 Silicon wafer 42 Silicon carbide thin film 43 Laminated body 44 Graphite support 45 Nuki hole 46 X-ray absorber film 47 Electron beam resist 48 Resist pattern 49 X-ray absorber pattern 50 X-ray mask

Claims (8)

[Claims] In a method for obtaining a thin film supported by a support, first, a thin film is deposited and laminated on a substrate made of a material that transforms into a liquid phase or a gas phase at a temperature lower than a transformation temperature of a substance forming the thin film. After forming a body, and then adhering the laminate to a support made of a substance that does not undergo phase conversion at the transformation temperature of the base body to form a composite body, the composite body is transformed at a temperature not lower than the transformation temperature of the base body and subjected to thin film transformation. A method for forming a thin film with a support, comprising the step of removing the substrate by heat treatment at a temperature lower than the temperature. 2. The method for forming a thin film with a support according to claim 1, wherein the thin film and the support are chemically bonded at the interface by heat treatment of the composite. 3. The material for forming a thin film is silicon carbide or carbon, and the substrate is silicon.
Alternatively, the method for forming a thin film with a support according to item 2. 4. Heat C as a method for depositing a thin film on a substrate.
4. The method for forming a thin film with a support according to claim 1, wherein the VD method is used. 5. The heat treatment of the composite is performed by using hydrogen, oxygen, chlorine,
5. The method for forming a thin film with a support according to claim 1, wherein the method is performed in an atmosphere containing at least one of fluorine. 6. The heat treatment of the composite is performed with helium, neon,
6. The method for forming a thin film with a support according to claim 1, wherein the method is performed in an atmosphere containing at least one of argon, xenon, and nitrogen or in a vacuum. 7. A method of manufacturing a substrate for an X-ray mask, which comprises a step of obtaining an X-ray transparent film made of silicon carbide whose peripheral portion is supported by a support frame. First, a silicon carbide thin film is deposited on a base made of silicon. To form a laminated body, and then adhere the laminated body to a supporting frame that supports the peripheral portion of the thin film, and then heat-treat the substrate at a temperature not lower than the transformation temperature of silicon and lower than the transformation temperature of silicon carbide to give the substrate. A method for manufacturing an X-ray mask substrate, comprising a step of removing. 8. A method for manufacturing an X-ray mask, which comprises manufacturing an X-ray mask using the substrate for X-ray mask manufactured by the method for manufacturing a substrate for X-ray mask according to claim 7.