JPH0854726A - Production of x-ray mask and x-ray mask obtained by that method - Google Patents

Abstract

PURPOSE:To obtain a production method of an X-ray mask having a dense and smooth X-ray absorbent by carrying out a process to form the absorbent, process to form a diamond film, and then a process to remove the substrate. CONSTITUTION:First, a W-Ti alloy X-ray absorbent 21 is formed by sputtering on a thin Si substrate 31 having smooth surface. Then, the film is annealed in vacuum or nitrogen atmosphere at a high temp. and stress in the X-ray absorbent is measured and made to be <10 MPa stress. Then, a base film 3 such as ITO is formed on the X-ray absorbent 21 by vapor deposition or sputtering and again annealed to obtain a stable crystal. Then, a diamond film 22 is formed on the base film 3 by using a hot filament or microwave discharge. A reinforcing ring 23 is adhered to the edge part of the diamond film 22. Then, the Si substrate 31 is removed by dissolving in hydrofluoric/nitric acid. A Cr film as an etching mask 6 is formed by sputtering on the exposed X-ray absorbent 21, and then a resist film 13 is formed on the Cr film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an X-ray mask for X-ray lithography and an X-ray mask obtained thereby, and a method for manufacturing an X-ray mask using a diamond thin film and the same. X-ray mask.

[0002]

2. Description of the Related Art FIG. 7 is a sectional view showing a conventional X-ray mask disclosed in, for example, Japanese Unexamined Patent Publication No. 5-217862.
In the figure, 1 is a silicon (Si) substrate having a thickness of about 2 mm with a central portion removed, and 2 is a film formed on a Si substrate 1 and made of light element ceramics such as silicon carbide (SiC) having good X-ray transmittance. A membrane thin film (free-standing film) having a thickness of about 2 μm, 3 is a base film made of a material having a high visible light transmittance such as indium tin oxide (ITO), etc. to prevent charging by charged particles, 4 is a semiconductor integrated in the central portion An X-ray absorber made of a tungsten (W) alloy (W-Ti alloy) in which a circuit pattern 5 is formed and containing 1 to 2% of titanium (Ti), and 6 is an etching mask made of a chromium (Cr) metal film. .

Next, a method of manufacturing the X-ray mask will be described with reference to FIG. First, on the upper surface of the Si substrate 1, Si
A C film 11 is formed (FIG. 3A), and then the central portion of the Si substrate 1 is dissolved and removed from below using an etching solution such as hydrofluoric nitric acid to form a SiC membrane thin film 2 (FIG. 2B). )). Then, an ITO base film 3, a W—Ti alloy X-ray absorber 4, a Cr film 12 serving as an etching mask 6, and a resist film 13 are formed on the membrane thin film 2 by using a sputtering method or a spin coating method (rotary coating method). Are sequentially formed ((c) in the same figure). Next, the resist film 13 is scanned with an electron beam (EB) (not shown) to form a semiconductor integrated circuit pattern 14 on the resist film 13 (FIG. 3D), and a pattern is formed using a mixed gas of Cl ₂ / O _2. 14
The Cr film 12 is etched by using the as an etching mask ((e) in the figure). Then, using a mixed gas of SF ₆ / CHF ₃ , the X-ray absorber 4 is subjected to low-temperature etching in a state where the Si substrate 1 is cooled to -50 ° C from the bottom portion by low-temperature helium (He), and the pattern 5 of the semiconductor integrated circuit is formed. After the formation, the resist film 13 is removed ((f) in the same figure).

ITO of the base film 3 has a large etching selectivity with respect to the W--Ti alloy and is stable even if the etching time is long, so that it is suitable as an etching stopper.
A pattern 5 having a constant depth and a vertical etching surface can be formed on the X-ray absorber 4 of a -Ti alloy.

The X-ray mask is arranged in parallel with the surface of the Si wafer coated with the exposure material (resist) while keeping a distance of 10 to 50 μm, and a synchrotron (Synchro-tr) is formed.
On radiation (SR) By irradiating an X-ray emitted from a radiation light source, the pattern 5 which is a fine processing pattern on a mask can be transferred onto a Si wafer.
Since the X-ray exposure method using this X-ray mask is excellent in the straightness of X-rays, it is possible to form a highly precise fine pattern as compared with the conventional electron beam exposure, ultraviolet exposure and the like.

[0006]

Since the conventional X-ray mask and the manufacturing method thereof are configured as described above, in order to enhance the positional accuracy of the minute pattern 5 of the quarter micron level, the membrane thin film 2 is formed. It is necessary to increase the Young's modulus and to reduce the stress of the X-ray absorber 4, and in order to further improve the dimensional accuracy of the pattern 5, the crystal grain size of the X-ray absorber 4 should be extremely reduced, or It must be crystalline. Therefore, since the diamond film has a high Young's modulus, attempts have been made to use the diamond film as a membrane thin film, and various proposals have been made.

However, the diamond film has a conventional S
As compared with the iC film, the crystal grain size is likely to be large, and the unevenness of the surface after film formation is large, so that the smoothness of the film is deteriorated. In this case, the X-ray absorber formed on the diamond film or the ITO film on the diamond film is likely to be crystallized, which makes it difficult to form a stable amorphous structure. In addition, although appropriate stress is required for the membrane thin film 2, the stress of a normal diamond film is considerably large. For example, when a diamond film is used as the membrane thin film 2 in the above manufacturing process, the central portion of the Si substrate 1 is dissolved and removed. Due to the stress of the diamond film,
There has been a problem that the i-substrate 1 is largely warped or distorted, and in an extreme case, it is damaged.

Therefore, as a remedy for reducing the unevenness of the surface, (a) SOG (Spin on Glass) is applied to the underlayer film 3 to improve the smoothness, and (b) the surface of the underlayer film 3 is not treated by plasma treatment. It may be crystallized, or (c) the sputtering pressure may be lowered at the time of forming the X-ray absorber 4 to facilitate the amorphization of the W-Ti alloy.
Since the resistance to the wire is weak, there is a problem that it is easily deteriorated and the film is easily peeled off. Also, in (b), the effect of reducing unevenness is small, and in (c) the stress of the W-Ti alloy becomes too large. There was a problem.

The present invention has been made to solve the above problems, and the inventions of claims 1 to 3 provide a method for manufacturing an X-ray mask having a dense and smooth X-ray absorber. The purpose is to provide.

It is an object of the present invention to provide a method of manufacturing an X-ray mask capable of preventing fogging between adjacent chips during X-ray exposure.

It is an object of the present invention to provide a method for manufacturing an X-ray mask, which can improve the positional accuracy of a pattern.

It is an object of the present invention to provide a method for manufacturing an X-ray mask which further improves smoothness.

It is an object of the invention of claim 7 to provide a method for manufacturing an X-ray mask capable of preventing warping and distortion by controlling the stress of the diamond film.

The invention of claim 8 is a dense and smooth X
An object of the present invention is to obtain an X-ray mask that can improve the dimensional accuracy of a pattern by having a ray absorber.

[0015]

X according to the invention of claim 1
A method of manufacturing a line mask includes an absorber forming step of forming an X-ray absorber having an amorphous or microcrystalline structure on a smooth surface of a thin substrate, and a diamond film on the X-ray absorber. A diamond film forming step of forming a film, a substrate removing step of removing the substrate from the X-ray absorber, and a pattern forming step of forming a predetermined pattern on the X-ray absorber.

The method of manufacturing an X-ray mask according to a second aspect of the present invention comprises a thin film forming step of forming a thin film serving as a light antireflection film on the X-ray absorber after the absorber forming step. It is a thing.

The method for manufacturing an X-ray mask according to a third aspect of the present invention comprises, after the diamond film forming step, a reinforcing step of providing a reinforcing member for the X-ray mask on the peripheral edge of the diamond film.

In the method of manufacturing an X-ray mask according to a fourth aspect of the present invention, the substrate removing step is a step of removing a portion of the substrate other than the peripheral portion.

In a method of manufacturing an X-ray mask according to a fifth aspect of the present invention, in the substrate removing step, a portion of the substrate other than a peripheral portion is removed and an electron beam drawing position detection mark is formed on the peripheral portion. It is a process.

In a method for manufacturing an X-ray mask according to a sixth aspect of the present invention, in the diamond film forming step, diamond microcrystals having a grain size of several to several tens nm or less are supplied together with a raw material gas containing a carbon compound, This is a step of forming a diamond film containing the diamond microcrystals while decomposing the source gas.

According to a seventh aspect of the present invention, in the method of manufacturing an X-ray mask, in the diamond film forming step, the stress of the film is adjusted by changing the concentration of the carbon compound in the raw material gas and the decomposition condition of the raw material gas. , By the combination of films with different stress,
This is a step for controlling the stress of the diamond film to be formed.

An X-ray mask according to an eighth aspect of the present invention is produced by the method of manufacturing an X-ray mask according to any one of the first to seventh aspects.

[0023]

In the method of manufacturing an X-ray mask according to the invention of claim 1, the unevenness of the surface is obtained by performing the substrate removing step of removing the substrate after performing the absorber forming step and the diamond film forming step. It is possible to form an amorphous or microcrystalline X-ray absorber having a fine structure and a high smoothness, and thus it is possible to form an X-ray mask having a high pattern dimensional accuracy.

In the method of manufacturing an X-ray mask according to a second aspect of the present invention, after the absorber forming step, a base film having a high light transmission of ITO or the like and having a light reflection preventing function is provided on the X-ray absorber. As a result, the alignment at the time of transfer can be performed with high accuracy.

The method of manufacturing an X-ray mask according to a third aspect of the present invention includes a reinforcing step of providing a reinforcing member on the peripheral edge of the diamond film after the diamond film forming step, whereby the mechanical strength of the X-ray mask is improved. Strength is improved.

In the method of manufacturing an X-ray mask according to a fourth aspect of the present invention, the substrate removing step is a step of removing a portion other than the peripheral portion of the substrate, so that when the X-ray exposure is performed, the X-ray mask penetrates from the periphery. It becomes possible to create an X-ray mask that blocks X-rays at the peripheral portion and prevents fogging between adjacent chips.

According to a fifth aspect of the present invention, in the method of manufacturing an X-ray mask, the step of removing the substrate is a step of removing a portion other than the peripheral portion of the substrate and forming an electron beam drawing position detection mark on the peripheral portion. By doing, X
X-rays penetrating from the periphery during line exposure are blocked by the peripheral portion to prevent fogging between adjacent chips, and improve pattern position accuracy during pattern writing.
It is possible to create a line mask.

In the method of manufacturing an X-ray mask according to the invention of claim 6, the raw material gas containing a carbon compound and the particle size of several to several.
By supplying diamond microcrystals of several tens of nm or less and forming a diamond film containing the diamond microcrystals while decomposing the raw material gas, the diamond microcrystals become secondary nuclei on the film surface and The complete diamond microcrystals grow to form a dense polycrystalline diamond film. As a result, it becomes possible to form a diamond film having small surface irregularities, which is formed of diamond microcrystals having a small grain size.

In the method of manufacturing an X-ray mask according to the invention of claim 7, the stress of the film is adjusted by changing the concentration of the carbon compound in the raw material gas and the decomposition condition of the raw material gas, and a combination of films having different stresses is combined. By controlling the stress of the diamond film to be formed, the stress of the diamond film is kept within an appropriate stress range.

The X-ray mask according to the invention of claim 8 is produced by the method of manufacturing an X-ray mask according to any one of claims 1 to 7, whereby the smoothness of the X-ray absorber is improved,
Therefore, the dimensional accuracy of the pattern is improved. Further, it becomes possible to provide an X-ray mask having the characteristics produced by each manufacturing method.

[0031]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1 in which the same parts as those in FIG. 7 are designated by the same reference numerals and duplicate description is omitted, 21 is an X-ray made of an amorphous W—Ti alloy in which the pattern 5 of the semiconductor integrated circuit is formed in the central portion. The absorber, 22 is a diamond film, and 23 is a reinforcing ring (reinforcing member) having a thickness of about 2 mm.

Next, a method of manufacturing the X-ray mask will be described with reference to FIG. First, the surface has a smooth thickness of 10
An X-ray absorber 21 of a W—Ti alloy is deposited on the Si substrate 31 having a thin thickness of about 0 to 300 μm by a sputtering method (absorber forming step (a) in the figure). Since the Si substrate 31 has a smooth surface, an amorphous W—Ti alloy film can be easily formed. Then, high temperature annealing is performed at about 800 ° C. in a vacuum or a nitrogen atmosphere to obtain the X-ray absorber 2
The stress of 1 is measured and set to a stress of 10 MPa or less. In order to accurately measure the stress, it is important that the Si substrate 31 be thin.

Next, the underlying film 3 made of ITO or the like is formed on the X-ray absorber 21 by a vapor deposition method, a sputtering method, a spin coating method or the like and annealed again to form a stable crystal (thin film forming step b)). Then, the diamond film 22 is formed on the base film 3 by using a hot filament or microwave discharge.
Is formed (diamond film forming step (c) in the same figure). By polishing or irradiating the surface of the diamond film 22 with the laser, the irregularities on the surface can be further improved.

Then, a reinforcing ring 23 is adhered to the peripheral edge of the diamond film 22 (reinforcing step (d) of the same figure).
In this case, the adhesive strength is increased if the portion to which the reinforcing ring 23 is attached is left unpolished without being polished.
Next, the Si substrate 31 is dissolved and removed using hydrofluoric nitric acid or the like,
When a Cr film to be the etching mask 6 is formed on the exposed X-ray absorber 21 by a sputtering method and a resist film 13 is formed on the Cr film (FIG. 8E), a conventional X-ray mask (FIG. 8) is formed. The structure is similar to that of (c). After the step of forming the pattern 14 on the resist film 13 (after FIG. 8D), it is exactly the same as the conventional X-ray mask manufacturing method.

As described above, according to the X-ray mask manufacturing method of this embodiment, the X-ray absorber 21, the base film 3 and the diamond film 22 are sequentially formed on the Si substrate 31, and then the Si substrate is formed. Since 31 is removed, the dense X-ray absorber 21 can be formed, the surface smoothness is improved, and the X-ray mask with high dimensional accuracy of the pattern can be manufactured.

Similar effects can be obtained even if the X-ray absorber 21 has a polycrystalline structure of fine crystals. Further, in the above-described embodiment, the antireflection film made of ITO is used as the base film 3, but the base film 3 is not limited to ITO and may be, for example, SOG or Cr.
A material such as O ₂ or Al ₂ O ₃ may be used, or an etching stopper material such as Cr may be used. In some cases, the diamond film may be directly formed on the X-ray absorber. Although the W-Ti alloy is used as the X-ray absorber 21, pure W, nitride, or tantalum (Ta) is used.
The same effect can be obtained by using or a mixture thereof.

Example 2. FIG. 3 shows the X of the second embodiment of the present invention.
6 is a cross-sectional view showing a line mask, in which a window 41 is formed in a portion where a pattern 5 is to be formed, instead of removing the entire Si substrate 31 as in the X-ray mask of the first embodiment. In this X-ray mask, the X-rays penetrating from the surrounding are the Si substrate 3
Since it is blocked by 1, it is possible to prevent fogging between adjacent chips when performing X-ray exposure. Further, an electron beam drawing position detection mark 42 is formed on the Si substrate 31.

Next, a method of manufacturing this X-ray mask will be described with reference to FIG. The procedure is the same as that of the first embodiment until the reinforcing ring 23 is bonded. The resist film 13 is applied onto the Si substrate 31 by the spin coating method (FIG. 9A), and the window 4 having high dimensional and positional accuracy is obtained by using optical transfer.
1 and the electron beam writing position detection mark 42 are formed (FIG. 2B). Next, C which becomes the etching mask 6
The r film is sequentially formed, and the pattern 5 is formed on the X-ray absorber 21 by the same method as the conventional method (FIG. 7C).

In this X-ray mask, the electron beam drawing position detection marks 42 are formed on the Si substrate 31, so the electron beam drawing position detection marks 42 are read when the circuit pattern is drawn by the electron beam. Since it is possible to draw while correcting the pattern position, it is possible to improve the pattern position accuracy.

Example 3. FIG. 5 is a schematic configuration diagram showing a diamond film forming apparatus used in a method of manufacturing an X-ray mask according to a third embodiment of the present invention. In the figure, 51 is a film forming substrate, 52 is a rotatable substrate holder, and Reference numeral 53 is a supply pipe for supplying a raw material gas consisting of a mixed gas of methane (CH ₄ ) and hydrogen (H ₂ ), 54 is a midstream of the supply pipe 53, and diamond microcrystals having a particle size of several nm are mixed in the raw material gas. The microcrystal feeder 55 is a hot filament made of W or the like.

Next, a method for forming a diamond film using this diamond film forming apparatus will be described. When the hot filament 55 is heated to a predetermined temperature, for example 2000 ° C., the film-forming substrate 51 is heated by its radiant heat,
The substrate temperature is 800 to 900 ° C. When the raw material gas containing diamond microcrystals is supplied in this state, the raw material gas is decomposed on the surface of the hot filament 55 and in the high temperature region in the vicinity thereof, and diamond microcrystals are deposited on the film formation substrate 51, so that the mechanical strength is increased. It is possible to obtain a diamond film having a large surface and small unevenness.

In the conventional diamond synthesis method, as shown in FIG.
As shown in FIG. 6A, since the diamond microcrystals 57 grow in grain size, the grain size increases as the film thickness increases, and the surface irregularities increase. However, in the synthesis method of this embodiment, as shown in FIG.
As shown in (b), the supplied diamond microcrystals serve as secondary nuclei on the surface of the film, and the diamond microcrystals 58 having a uniform grain size grow to form a dense diamond film.

The film forming substrate 51 of the above-mentioned embodiment is the base film 3
It may be other than the Si substrate 31 on which the X-ray absorber 21 is formed. For example, when a Si substrate is used, the diamond film can be directly formed on the Si substrate. In addition to the above CH ₄ , hydrocarbons such as C ₂ H ₂ and alcohols such as CH ₃ OH, CO, and CO ₂ are used as the components of the raw material gas.
It is also possible to use oxides such as the above, fluorides such as CF ₄ and chlorides. Further, as a means for decomposing the raw material gas, in addition to the above-mentioned hot filament 55, electric discharge such as microwave or arc, high temperature gas such as acetylene flame, or the like can be used.

The diamond film used for the X-ray mask is required to have stress. However, if the stress is not within an appropriate range, the Si substrate may be deformed or damaged by the stress. Therefore, the stress can be adjusted by changing the ratio of methane and hydrogen as the raw materials during the reaction. That is, when the CH ₄ concentration is increased, diamond becomes fine crystals and the stress increases. On the other hand, CH
_{4 If the} concentration is lowered, the generation of secondary nuclei is suppressed, the diamond microcrystals grow into grains, and the stress decreases. At the beginning of film formation, the CH ₄ concentration is increased to refine the crystal, and then CH ₄
The stress can be adjusted to a proper range by reducing the concentration and growing the grains to some extent. The ratio of the time (= film thickness) for forming the film at each concentration may be set so that the total stress falls within an appropriate range.

When microwave plasma is used, the stress increases as the plasma intensity increases, and the stress decreases as the plasma intensity decreases. Therefore, in order to keep the stress of the diamond film within an appropriate stress range, the plasma intensity may be adjusted appropriately by increasing the plasma intensity first and then decreasing the plasma intensity.

[0046]

As described above, according to the invention of claim 1, an absorber forming step of forming an X-ray absorber made of either amorphous or microcrystalline on a smooth surface of a thin substrate, ,
A diamond film forming step of forming a diamond film on the X-ray absorber and a substrate removing step of removing the substrate are provided, and a predetermined pattern is formed on the X-ray absorber in the pattern forming step. As a result, it is possible to form an X-ray absorber having an amorphous or microcrystalline dense structure with small surface irregularities and excellent smoothness, and it is possible to form an X-ray mask with high pattern dimensional accuracy. effective.

According to the invention of claim 2, after the absorber forming step, a base film having a high light transmittance such as ITO and having an antireflection function is provided on the X-ray absorber. Therefore, there is an effect that alignment at the time of transfer can be performed with high accuracy.

According to the invention of claim 3, after the diamond film forming step, a reinforcing member is provided in the peripheral portion of the diamond film in the reinforcing step, so that the mechanical strength of the X-ray mask is improved. There is an effect that can be.

According to the fourth aspect of the invention, in the substrate removing step, the portion excluding the peripheral portion of the substrate is removed. Therefore, fogging between adjacent chips during X-ray exposure can be prevented. There is an effect that a mask can be created.

According to the fifth aspect of the present invention, in the substrate removing step, a portion other than the peripheral portion of the substrate is removed and the electron beam writing position detection mark is formed on the peripheral portion. There is an effect that fogging between adjacent chips can be prevented during X-ray exposure, and an X-ray mask that can improve the pattern position accuracy at the time of pattern drawing can be created.

According to the invention of claim 6, in the diamond film forming step, the source gas containing the carbon compound and the diamond microcrystals having a grain size of several to several tens nm are supplied to decompose the source gas. Since the diamond film containing the diamond microcrystals is formed, the diamond microcrystals serve as secondary nuclei to form a dense diamond film having small irregularities on the surface, which is composed of diamond microcrystals having a uniform grain size. There is an effect that can be.

According to the invention of claim 7, the stress of the film is adjusted by changing the concentration of the carbon compound in the raw material gas and the decomposition condition of the raw material gas, and the film is formed by combining the films having different stresses. Since the stress of the diamond film is controlled, the stress of the diamond film can be kept within an appropriate stress range.

According to the eighth aspect of the invention, since the X-ray mask is produced by the method for producing an X-ray mask according to any one of the first to seventh aspects, the X-ray absorber having excellent smoothness is provided. Therefore, it is possible to provide an X-ray mask having a high pattern dimensional accuracy. Further, there is an effect that it is possible to provide an X-ray mask having a characteristic feature produced by each manufacturing method.

[Brief description of drawings]

FIG. 1 is a sectional view showing an X-ray mask according to a first embodiment of the present invention.

FIG. 2 is a process chart showing a method for manufacturing an X-ray mask according to a first embodiment of the present invention.

FIG. 3 is a sectional view showing an X-ray mask according to a second embodiment of the present invention.

FIG. 4 is a process diagram showing a method for manufacturing an X-ray mask according to a second embodiment of the present invention.

FIG. 5 is a schematic configuration diagram showing a diamond film forming apparatus used in a method for manufacturing an X-ray mask according to a third embodiment of the present invention.

FIG. 6 is a schematic view showing a film formation state of a diamond film.

FIG. 7 is a sectional view showing a conventional X-ray mask.

FIG. 8 is a process diagram showing a conventional method for manufacturing an X-ray mask.

[Explanation of symbols]

3 Underlayer film, 21 X-ray absorber, 22 Diamond film, 23 Reinforcing ring (reinforcing member), 31 Si substrate (substrate), 42 Electron beam drawing position detection mark, 5
8 Diamond microcrystal.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location H01L 21/027 (72) Inventor Yasuji Matsui 8-1-1 Tsukaguchihonmachi, Amagasaki-shi Mitsubishi Electric shares Company Semiconductor Research Laboratory (72) Inventor Kenji Marumoto 8-1-1 Tsukaguchi Honcho, Amagasaki City Mitsubishi Electric Corporation Semiconductor Research Laboratory (72) Inventor Hideki Yabe 8-1-1 Tsukaguchi Honcho, Amagasaki Mitsubishi Electric Semiconductor Basic Research Institute Co., Ltd.

Claims (8)

[Claims] 1. An absorber forming step of forming an X-ray absorber made of either amorphous or fine crystal on a smooth surface of a thin substrate, and forming a diamond film on the X-ray absorber. An X-ray mask manufacturing method comprising: a diamond film forming step; a substrate removing step of removing the substrate; and a pattern forming step of forming a predetermined pattern on the X-ray absorber. 2. The X-ray mask according to claim 1, further comprising a thin film forming step of forming a base film for preventing light reflection on the X-ray absorber after the absorber forming step. Manufacturing method. 3. The X-ray mask according to claim 1, further comprising a reinforcing step of providing a reinforcing member on a peripheral portion of the diamond film after the diamond film forming step. Production method. 4. The method of manufacturing an X-ray mask according to claim 1, wherein the substrate removing step is a step of removing a portion of the substrate other than a peripheral portion. 5. The substrate removing step is a step of removing a portion except a peripheral portion of the substrate and forming an electron beam drawing position detection mark on the peripheral portion. Method for manufacturing X-ray mask. 6. The diamond film forming step comprises supplying diamond microcrystals having a particle size of several to several tens nm or less together with a raw material gas containing a carbon compound, and decomposing the raw material gas and diamond containing the diamond microcrystals. The method of manufacturing an X-ray mask according to claim 1, wherein a film is formed. 7. The diamond film forming step adjusts the stress of the film by changing the concentration of the carbon compound in the raw material gas and the decomposition condition of the raw material gas, and forms the film by combining the films having different stresses. The method of manufacturing an X-ray mask according to claim 1, wherein the stress of the diamond film is controlled. 8. An X-ray mask manufactured by the method for manufacturing an X-ray mask according to claim 1.