JP3339201B2 - X-ray exposure mask and X-ray exposure mask blank - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an LSI, VLSI, U
An X-ray exposure mask required for forming an extremely fine pattern represented by the manufacture of a semiconductor integrated circuit such as an LSI by X-ray lithography, and a mask for manufacturing the X-ray exposure mask The present invention relates to an X-ray exposure mask blank which is an intermediate product.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 8, an X-ray exposure mask comprises an X-ray absorbing pattern film 1, an X-ray transmitting supporting film 3 for supporting the X-ray absorbing pattern film 1, and an X-ray absorbing support film 3. And a support frame 5 that supports the transmission support film 3 on the outer peripheral side. Also,
The X-ray exposure mask blank is a state before the X-ray absorbing film is processed into the X-ray absorbing pattern film 1, and the X-ray absorbing film, the X-ray transmitting supporting film 3, and the supporting frame 5 are separated from each other. And a supporting substrate before being formed. In addition, both the X-ray exposure mask and the X-ray exposure mask blank have a structure in which the glass pedestal 11 is bonded to the back surface of the support substrate before the support frame 5 is formed.

An X-ray exposure mask as shown in FIG. 8 used for an X-ray pattern exposure operation is, for example, an X-ray photosensitive resist film (or a photo-resist film) provided on a semiconductor substrate (silicon substrate) surface. X-ray pattern irradiation through this X-ray exposure mask, selective exposure of a part of the resist film by X-rays, and development processing To expose the surface of the semiconductor substrate in a pattern. Then, the desired semiconductor element can be obtained by selectively processing the exposed surface by various methods.

In the exposure of the X-ray photosensitive resist film, alignment marks (register marks) are previously provided on both of the semiconductor substrate and the X-ray exposure mask in order to align them. Is provided. Then, after the two are brought close to each other in parallel at a predetermined interval, the wavelength not sensitive to the resist film (the wavelength in a vacuum or in the air is 400 to 700 nm in the visible region through the X-ray exposure mask). By irradiating alignment light of a certain wavelength) and measuring the reflected light from the surface of the semiconductor substrate and the surface of the mask for X-ray exposure and aligning the positions of both alignment marks, the semiconductor substrate and the X-ray exposure Masks are aligned.

However, since the refractive index n of the X-ray transmitting support film 3 is significantly different from the refractive index n _{0 of the} atmosphere, the alignment light is reflected on both the front and back surfaces of the support film 3 and the generated reflected light The light to be measured from the surface of the semiconductor substrate interferes with each other, and the light intensity increases or decreases, or a diffraction phenomenon occurs, and as a result, the alignment accuracy may decrease. Such a decrease in accuracy is due to the above X
This can be prevented by strictly controlling the optical film thickness of the radiation transmitting support film 3, but it is difficult to strictly control the film thickness in order to prevent such visible light interference.

On the other hand, as shown in FIG. 8, on the front and back surfaces of the X-ray transmission supporting film 3 of the X-ray exposure mask, a refractive index substantially equal to the square root of the refractive index n of the X-ray transmission supporting film 3 is formed. 1
By providing the antireflection film 2 and the second antireflection film 4,
It is known that the reflected light from the front and back surfaces of the X-ray transmission support film 3 can be canceled or suppressed, and thus the alignment accuracy can be improved.

In order to obtain such a mask structure for X-ray exposure, first, on a frame substrate made of a silicon substrate which will later become the entire structural support frame 5, a X-ray transparent support film 3 on the back side is formed. (2) an anti-reflection film 4, an X-ray transmission supporting film 3, a first anti-reflection film 2 on the surface (main surface) side of the X-ray transmission supporting film 3, and an X-ray absorbing film (hereinafter referred to as X-ray absorbing (A film forming the pattern film 1) are sequentially formed to obtain a mask blank for X-ray exposure. Next, the X-ray absorbing film is patterned into a mask pattern for exposure to form an X-ray absorbing pattern film and an alignment mark at the same time, and then the frame substrate made of the silicon substrate is selectively etched by back etching. It can be manufactured in principle by forming a frame 5 and a window 7 through which X-rays and alignment light are transmitted by pattern etching.

[0008]

Generally, the first and second antireflection films 2 and 4 are made of silicon dioxide (SiO ₂ ).
Alternatively, an alumina film (Al ₂ O ₃ ) is used. In manufacturing an X-ray exposure mask having such a structure, the second anti-reflection film 4 on the back surface of the X-ray transmission support film 3 is provided with an X-ray and an alignment film. When forming the window part 7 through which light is transmitted, it is not resistant to a hot alkali solution used as an etchant for the silicon frame substrate. The anti-reflection film is also etched, and in the worst case, the second anti-reflection film is completely peeled off.

Therefore, as shown in FIG. 8, a supplementary anti-reflection film 4a is formed again so as to supplement the second anti-reflection film 4 on the back side of the X-ray transmission support film 3 as a final step after the back etching. In this case, in order to perform the process of forming the supplementary anti-reflection film 4a from the back side of the X-ray transmission support film 3 made of a thin film having a thickness of about 0.5 to 3.0 μm, The X-ray transmissive support film 3 is broken in the processing apparatus or the vacuum apparatus, and the X-ray absorptive pattern film 1 is formed by the internal stress of the supplementary anti-reflection film 4a formed on the back side of the X-ray transmissive support film 3. However, the danger of displacement was inevitable.

The present invention has been made in view of the above problems, and an object of the present invention is to omit the process of replenishing the supplementary anti-reflection film 4a from the back side of the X-ray transmission support film. And the risk of the X-ray transmission supporting film being broken in the processing apparatus or the vacuum apparatus, and the position of the X-ray absorbing pattern film due to the internal stress of the supplementary anti-reflection film formed on the back side of the X-ray transmission supporting film. Avoid displacement and X
An object of the present invention is to improve the positional accuracy of a line exposure mask and an X-ray exposure mask blank.

[0011]

The first invention of the present invention is shown in FIG.
As shown in the side sectional view of FIG. 1, a silicon frame 5 having a window 7 formed therein, an X-ray transmission support film 3 supported by the frame 5,
An X-ray absorbing pattern 1 made of heavy metal provided on the X-ray transmitting supporting film 3, and a first antireflection film 2 between the X-ray absorbing pattern 1 and the X-ray transmitting supporting film 3; In an X-ray exposure mask including a second antireflection film 4 between the X-ray transmission support film 3 and the frame 5, a first antireflection film 2 made of a light element material and a light element material An X-ray exposure mask A, comprising: an X-ray transmission support film 3 made of, and a second antireflection film 4 made of a tin oxide film (SnO ₂ ) resistant to a hot alkaline solution.

Further, the X-ray exposure mask of the first invention is an X-ray exposure mask in which the first antireflection film 2 made of the light element substance is a tin oxide film (SnO ₂ ).

The X-ray exposure mask of the first invention is an X-ray exposure mask in which the first antireflection film 2 made of the light element substance is an alumina film.

Further, the X-ray exposure mask of the first invention is an X-ray exposure mask in which the first antireflection film 2 made of the light element substance is a silicon dioxide film.

The X-ray exposure mask according to the first invention is an X-ray exposure mask in which the first antireflection film 2 made of the light element substance is a sialon film.

The X-ray exposure mask of the first invention is an X-ray exposure mask in which the X-ray transmission support film 3 made of the light element substance is a silicon nitride film.

Further, the X-ray exposure mask of the first invention is an X-ray exposure mask in which the X-ray transmission support film 3 made of the light element substance is a silicon carbide film.

Next, according to a second aspect of the present invention, as shown in the side sectional view of FIG. 2, a tin oxide film (SnO ₂ ) resistant to a hot alkali solution is formed on a silicon frame substrate 9. A second antireflection film 4, an X-ray transmission support film 3 made of a light element material, a first antireflection film 2 made of a light element material, and an X-ray absorbing film 8 made of a heavy metal in this order. A mask blank B for X-ray exposure characterized by being provided.

Further, the mask blank for X-ray exposure according to the second aspect of the present invention is characterized in that the first antireflection film 2 made of the light element substance is used.
Is a mask blank for X-ray exposure, which is a tin oxide film (SnO ₂ ).

Further, the mask blank for X-ray exposure according to the second aspect of the present invention is characterized in that the first antireflection film 2 made of the light element substance is used.
Is a mask blank for X-ray exposure, which is an alumina film.

Further, the mask blank for X-ray exposure according to the second aspect of the present invention is characterized in that the first antireflection film 2 made of the light element substance is used.
Is a mask blank for X-ray exposure, which is a sialon film.

Further, the mask blank for X-ray exposure according to the second aspect of the present invention is characterized in that the first antireflection film 2 made of the light element substance is used.
Is an X-ray exposure mask blank which is a silicon dioxide film.

Further, the mask blank for X-ray exposure according to the second aspect of the present invention is the X-ray transparent support film 3 made of the light element substance.
Is a mask blank for X-ray exposure, which is a silicon nitride film.

Further, the mask blank for X-ray exposure according to the second aspect of the present invention is the X-ray transparent support film 3 made of the light element substance.
Is a mask blank for X-ray exposure, which is a silicon carbide film.

[0025]

EXAMPLES Examples of the X-ray exposure mask A of the first invention and the X-ray exposure mask blank B of the second invention used for manufacturing the X-ray exposure mask A according to the present invention will be described below. 3 (a) to 3 (d) will be described in detail below according to their manufacturing steps. In the X-ray exposure mask of the first invention, the first antireflection film 2
Is any one of a tin oxide film, an alumina film, a silicon dioxide film, and a sialon film, and the X-ray transmission support film 3 is any one of a silicon nitride film and a silicon carbide film. Is not particularly limited, and in the mask blank for X-ray exposure of the second invention, the first antireflection film 2 is made of any one of a tin oxide film, an alumina film, a silicon dioxide film, and a sialon film. The X-ray transmission support film 3 is any one of a silicon nitride film and a silicon carbide film, and the combination thereof is not particularly limited.

First, as shown in FIG. 3A, a second antireflection film 4 corresponding to the back surface side of the X-ray transmission support film 3 is coated on the surface (main surface) of the frame substrate 9 made of a silicon substrate by a sputtering method or the like. The film is formed using a thin film formation method.

Next, as shown in FIG. 3B, an X-ray transmission supporting film 3 is formed on the second anti-reflection film 4 formed by using the thin film forming method.
And a protective film 10 for back etching (resist film, etching resist film, etc.) on the back surface of the frame substrate 9.
Are formed using a known thin film forming method such as a sputtering method.

Thereafter, as shown in FIG.
A first anti-reflection film 2 is formed on the first anti-reflection film 2 by using a thin film forming method such as a sputtering method, and an X-ray absorbing film is formed on the first anti-reflection film 2 by using a thin film forming method such as a sputtering method. 8 to form a mask blank B for X-ray exposure.

Next, as shown in FIG. 3D, the protective film 10 is patterned using a photolithography method or the like to form a back etching mask 6 (etching resist pattern film). A portion corresponding to the window 7 (see FIG. 1) of the X-ray exposure mask A is used as an etching mask for forming by pattern etching.

FIG. 3D shows the X-ray absorbing film 8.
Is patterned by using a technique such as an electron beam lithography method or a photolithography method to obtain a fine X-ray absorbing pattern film 1 as a desired exposure mask pattern.

Finally, as shown in FIG. 3D, using the back etching mask 6 as an etching mask, the silicon frame substrate 9 is etched with a hot alkali solution until the silicon anti-reflection film 4 reaches the surface. By performing back etching and providing the frame 5 and the window portion 7 as shown in FIG. 1, the X-ray exposure mask A is obtained.

In the mask A for X-ray exposure and the mask blank B for X-ray exposure of the first invention, the film thickness of the first antireflection film 2 and the second antireflection film 4 is d = λ /
4n (d: film thickness, λ: X-ray exposure wavelength, n: refractive index of the film)
Is optimal. If the film thickness deviates from this value, a considerably high effect can be obtained, but the effect is higher as close to this value as possible. Although depending on the required specifications of the product, if it is close to this value, it can be used as the antireflection film even if there is some deviation from this value in practical use.
Even within a range of 30% or less, it has a considerable antireflection effect in practical use.

Although the thickness d of each of the first antireflection film 2 and the second antireflection film 4 is not particularly limited in the present invention, from the viewpoint of controlling the stress of the antireflection film itself, In practice, the thickness d of the anti-reflection film on at least one side (either the first anti-reflection film 2 or the second anti-reflection film 4) is desirably 200 nm or less.

The sialon film used for the first anti-reflection film 2 is an alloy made of silicon, aluminum, oxygen and nitrogen, and can be formed by sputtering using a sialon target.

FIG. 4 is a side sectional view showing another embodiment of the X-ray exposure mask according to the first invention of the present invention. The X-ray exposure mask according to one embodiment of the first invention shown in FIG. A glass substrate 11 having a portion corresponding to a window portion is previously bonded to the surface of the back etching mask 6 via an adhesive.

FIG. 5 is a side sectional view showing another embodiment of the mask blank for X-ray exposure before pattern formation of the X-ray absorbing pattern film 1. FIGS. 6 and 7 show X-ray exposure mask blanks. FIG. 9 is a side sectional view showing another embodiment of the mask blank for X-ray exposure before forming the pattern of the absorptive pattern film 1.

[0037]

In the X-ray exposure mask A and the X-ray exposure mask blank B according to the present invention, the anti-reflection film for suppressing the reflection of the alignment light (light for position alignment) has an X-ray transmission support film. (3) a first antireflection film 2 on both the front and back surfaces;
Since each of the second antireflection films 4 is provided with resistance to a hot alkali solution, good alignment accuracy by a sufficient antireflection action can be obtained.

Since the second antireflection film 4 has sufficient resistance to a hot alkaline solution used as an etchant when pattern-etching the window on the frame substrate, the second anti-reflection film 4 can be used for back etching of the window 7. The deterioration and damage of the second anti-reflection film 4 are avoided, and the anti-reflection effect according to the design value can be expected. As a result, the X-ray transmission support film 3 is broken in the processing apparatus or the vacuum apparatus. Danger can be greatly reduced.

Further, the X-ray exposure mask A according to the present invention,
In the mask blank B for X-ray exposure, since the second antireflection film 4 on the back surface side of the X-ray transmission support film 3 is a thin film that is not easily etched by a hot alkaline solution which is an etchant for a silicon substrate, the window portion 7 The deterioration and damage of the second antireflection film 4 due to the back etching are avoided, and the antireflection effect as designed can be expected.

Hereinafter, specific examples of the present invention will be described.

<Embodiment 1> The size is 3 inches in diameter and the thickness is 1.
mm on the surface (main surface) side of the silicon frame substrate 9.
A 50 nm tin oxide film is formed by a sputtering method,
A second anti-reflection film 4 of a tin oxide film was formed. (FIG. 3
(See (a))

Next, a silicon nitride film (SiN _x ) having a thickness of 2 μm is formed on both sides of the silicon frame substrate 9 on which the second antireflection film 4 is formed by a sputtering method. The X-ray transmission support film 3 made of a silicon nitride film was formed on the second antireflection film 4 on the front (main surface) side of the substrate, and the protective film 6 made of a silicon nitride film was formed on the back surface side of the frame substrate 9. (FIG. 3
(See (b))

Then, a tin oxide film having a thickness of 150 nm is formed on the X-ray transmitting support film 3 on the main surface side of the frame substrate 9 by a sputtering method, and the main surface (surface) of the X-ray transmitting supporting film 3 is formed. The first antireflection film 2 of the tin oxide film was formed on the side (). Further, an X-ray absorbing film 8 is formed by forming a tantalum film (Ta) to a thickness of 700 nm on the first antireflection film 2 by a sputtering method.
A mask blank B for line exposure was obtained. (FIG. 2, FIG. 3 (c)
reference)

Next, the desired X-ray absorbing pattern film 1 was obtained by patterning the X-ray absorbing film 8 of the mask blank B for X-ray exposure using electron beam lithography or photolithography. (See Fig. 3 (d))

The protective film 10 made of a silicon nitride film formed on the back surface of the frame substrate 9 was patterned by photolithography to form a back etching mask 6 for providing the window 7 in the frame substrate 9. . (See Fig. 3 (d))

Finally, using the back etching mask 6 (etching resist pattern film), the back surface of the frame substrate 9 is coated on the second anti-reflection film 4 with a 30% concentration, 90 ° C. aqueous solution of potassium hydroxide. By back-etching until reaching, the frame substrate 9 was formed on the frame 5 and the window 7 was formed, thereby obtaining the X-ray exposure mask A of the present invention.
(See Fig. 1)

In the X-ray exposure mask A of the present invention thus manufactured as shown in FIG. 1, the second antireflection film 4 on the back surface of the X-ray transmission support film 3 is Since it is resistant to the etchant of etching, it is not necessary to go through the conventional dangerous process of forming the second antireflection film 4 after back etching, and it is designed before the mask blank B for X-ray exposure. An X-ray exposure mask A having an antireflection effect by the second antireflection film 4 was obtained.

<Embodiment 2> The size is 3 inches in diameter and the thickness is 1.
mm on the surface (main surface) side of the silicon frame substrate 9.
A 50 nm tin oxide film is formed by a sputtering method,
A second anti-reflection film 4 of a tin oxide film was formed. (FIG. 3
(See (a))

Next, a silicon carbide film (SiC) having a thickness of 2 μm is formed on both sides of the silicon frame substrate 9 on which the second anti-reflection film 4 is formed by a sputtering method. The X-ray transmission support film 3 made of a silicon carbide film was formed on the surface (main surface) side of the frame substrate 9, and the protective film 10 made of a silicon carbide film was formed on the back surface side. (See FIG. 3B)

Then, 100 nm is formed on the X-ray transmitting support film 3 on the surface (main surface) side of the frame substrate 9 by sputtering.
A thick alumina film was formed, and a first antireflection film 2 of an alumina film was formed on the surface (main surface) of the X-ray transmission support film 3. (See FIG. 3 (c))

Further, a 700 nm tantalum film is formed on the first antireflection film 2 by a sputtering method, and an X-ray absorbing film 8 is formed.
A mask blank B for line exposure was obtained. (FIG. 2, FIG. 3 (c)
reference)

Next, the protective film 10 made of a silicon carbide film formed on the back surface of the frame substrate 9 of the mask blank B for X-ray exposure is patterned by photolithography to form the back etching mask 6. Formed. (FIG. 3
(See (d))

Subsequently, the mask blank B for X-ray exposure
The X-ray absorbing film 8 made of a tantalum film on the surface (main surface side) of the frame substrate 9 was patterned by using an electron beam lithography method or a photolithography method to obtain a desired X-ray absorbing pattern film 1. (See Fig. 3 (d))

Finally, the X-ray exposure mask blank B
Using the back etching mask 6 made of a silicon carbide film as an etching mask, the back surface of the silicon frame substrate 9 reaches the surface of the second antireflection film 4 using an aqueous solution of potassium hydroxide having a concentration of 30% and a liquid temperature of 90 ° C. Back etching until the frame substrate 9 is formed on the frame 5 and the window 7
Was formed to obtain an X-ray exposure mask A of the present invention. (Figure 1
reference)

The second anti-reflection film 4 on the back surface of the X-ray transmission support film 3 of the mask A for X-ray exposure of the present invention thus produced is resistant to the etchant of the back etching. It is not necessary to go through the conventional dangerous process of forming the second anti-reflection film 4 on the back surface side of the X-ray transmission support film 3, and the second anti-reflection film 4 is provided before the mask blank B for X-ray exposure is formed. An X-ray exposure mask A having an antireflection effect as designed was obtained.

<Embodiment 3> The size is 3 inches in diameter and the thickness is 1
mm on the surface (main surface) side of the silicon frame substrate 9.
A 50 nm tin oxide film is formed by a sputtering method,
A second anti-reflection film 4 of a tin oxide film was formed. (FIG. 3
(See (a))

Next, a silicon carbide film having a thickness of 2 μm is formed on both surfaces of the frame substrate 9 on which the second antireflection film 4 is formed by a sputtering method. The X-ray transmission support film 3 made of a silicon carbide film was formed, and the protective film 10 made of a silicon carbide film was formed on the back surface side. (See FIG. 3B)

Then, a tin oxide film having a thickness of 150 nm was formed on the X-ray transmission support film 3 on the main surface side of the frame substrate 9 by a sputtering method to form the first antireflection film 2 of the tin oxide film. . (See FIG. 3 (c))

Further, a 700 nm tantalum film is formed on the first antireflection film 2 by a sputtering method, and an X-ray absorbing film 8 of a tantalum film is formed. B was obtained. (FIG. 3
(See (c))

Next, the X-ray absorbing film 8 made of a tantalum film on the surface (main surface side) of the mask blank B for X-ray exposure is patterned by electron beam lithography or photolithography to obtain a desired X-ray. A line absorber pattern film 1 was obtained. (See Fig. 3 (d))

The protective film 10 made of a silicon carbide film on the back side of the mask blank B for X-ray exposure was patterned by photolithography to form a back etching mask 6. (See Fig. 3 (d))

Finally, the X-ray exposure mask blank B
Using the back etching mask 6 on the back surface of the frame substrate 9 as an etching mask, the frame substrate 9 is back-etched with an aqueous solution of potassium hydroxide having a concentration of 30% and a liquid temperature of 90 ° C. until the surface of the second antireflection film 4 is reached. And frame 5 and window 7
Was formed. (See Fig. 4)

Thereafter, Pyrex glass having a window corresponding to a window portion is previously bonded as a glass pedestal 11 to the back etching mask 6 on the back surface of the frame substrate 9 via an adhesive, thereby obtaining the present invention. X-ray exposure mask was obtained. (See Fig. 4)

In the X-ray exposure mask A of the present invention thus manufactured, the second anti-reflection film 4 on the back surface side of the X-ray transmission support film 3 is resistant to the etchant of the back etching. There is no need to go through the conventional dangerous process of forming the second anti-reflection film,
An X-ray exposure mask A having an antireflection effect as designed before preparation of the X-ray exposure mask blank B was obtained.

<Embodiment 4> The size is 3 inches in diameter and the thickness is 1.
mm on the surface (main surface) side of the silicon frame substrate 9.
A 50 nm tin oxide film is formed by a sputtering method,
A second anti-reflection film 4 of a tin oxide film was formed. (FIG. 3
(See (a))

Next, a silicon nitride film having a thickness of 2 μm is formed on both surfaces (main surface and back surface) of the frame substrate 9 on which the second antireflection film 4 is formed by sputtering. The X-ray transmission support film 3 made of a silicon nitride film was formed on the front surface side, and the protective film 10 made of a silicon nitride film was formed on the back surface side. (FIG. 3
(See (b))

Then, a 100 nm-thick silicon dioxide film is formed on the X-ray transmission support film 3 on the main surface side of the frame substrate 9 by a sputtering method to form the first anti-reflection film 2. A 700 nm tantalum film was formed on the antireflection film 2 by a sputtering method to form an X-ray absorbing film 8 to obtain a mask blank B for X-ray exposure. (FIG. 3 (c)
reference)

Next, the back etching mask 6 was obtained by patterning the protective film 10 made of the silicon nitride film of the mask blank B for X-ray exposure using photolithography or the like. (See Fig. 3 (d))

Subsequently, the X-ray exposure mask blank B
The X-ray absorbing film 8 is patterned by using an electron beam lithography method or a photolithography method to provide a desired X-ray absorbing pattern film 1. (See Fig. 4)

Next, using the back etching mask 6 on the back surface of the frame substrate 9 as an etching mask,
The back surface of the frame substrate 9 is back-etched with an aqueous solution of potassium hydroxide at 0 ° C. until the back surface of the frame substrate 9 reaches the second antireflection film 4, thereby forming the frame 5 and the window 7. (See Fig. 4)

Next, a Pyrex glass provided with a window in advance is bonded as a glass pedestal 11 to the back etching mask 6 on the back surface of the frame substrate 9 via an adhesive, thereby obtaining the X-ray exposure of the present invention. A mask A for use was obtained. (See Fig. 4)

In the X-ray exposure mask A of the present invention thus manufactured, the second anti-reflection film 4 on the back surface side of the X-ray transmission support film 3 is resistant to the etchant of the back etching. It is not necessary to go through the conventional dangerous process of forming the second anti-reflection film 4, and the X-ray exposure mask A having the anti-reflection effect as designed before the preparation of the X-ray exposure mask blank B is used. Obtained.

<Embodiment 5> The size is 3 inches in diameter and the thickness is 1
mm on the surface (main surface) side of the silicon frame substrate 9.
A 50 nm tin oxide film is formed by a sputtering method,
A second anti-reflection film 4 of a tin oxide film was formed. (FIG. 3
(See (a))

Next, the front and back of the frame substrate 9 (main surface and back surface)
A silicon nitride film having a thickness of 2 μm was formed on both surfaces by a sputtering method to form an X-ray transmission support film 3 made of a silicon nitride film and a protective film 10 made of a silicon nitride film. (See FIG. 3B)

Then, a sialon film having a thickness of 130 nm is formed on the X-ray transmission support film 3 made of a silicon nitride film by a sputtering method to form a first anti-reflection film 2.
A 700 nm tantalum film is formed on the first anti-reflection film 2 of the sialon film by a sputtering method, and X
The line absorbing film 8 was formed. (See FIG. 3 (c))

Subsequently, the protective film 10 made of a silicon nitride film is patterned by using a photolithography method or the like.
A back etching mask 6 was formed. (See Fig. 3 (d))

Further, a Pyrex glass provided with a window as a glass pedestal 11 in advance as a glass pedestal 11 was bonded to the surface of the back etching mask 6 via an adhesive to obtain a mask blank B for X-ray exposure of the present invention. (See Fig. 5)

Subsequently, the X-ray exposure mask blank B
Is formed by patterning the X-ray absorbing film 8 using an electron beam lithography method or a photolithography method.
The line absorbing pattern film 1 is provided, and finally, the back surface of the frame substrate 9 is back-etched with a 30% concentration, 90 ° C. aqueous solution of potassium hydroxide using the back etching mask 6 on the back surface of the frame substrate 9 as an etching mask. As a result, the frame 5 and the window 7 were formed, and the mask A for X-ray exposure of the present invention was obtained. (See Fig. 4)

In the X-ray exposure mask A of the present invention thus manufactured, the second antireflection film 4 on the back surface side of the X-ray transmission support film 3 is resistant to the back etching etchant. It is not necessary to go through the conventional dangerous process of forming the second anti-reflection film 4 later, and the X-ray exposure mask A having the anti-reflection effect as designed before the preparation of the X-ray exposure mask blank is provided. Obtained.

<Embodiment 6> The size is 3 inches in diameter and the thickness is 1
mm on the surface (main surface) side of the silicon frame substrate 9.
A 50 nm tin oxide film is formed by a sputtering method,
A second anti-reflection film 4 of a tin oxide film was formed. (FIG. 3
(See (a))

Next, the front and back of the frame substrate 9 (main surface and back surface)
A silicon carbide film having a thickness of 2 μm was formed on both surfaces by a sputtering method to form an X-ray transmission support film 3 made of a silicon carbide film and a protective film 10 made of a silicon carbide film. (See FIG. 3B)

Then, a tin oxide film having a thickness of 150 nm is formed on the X-ray transmission
Forming an anti-reflection film 2;
A tantalum film is formed on the top using a sputtering method to a thickness of 700 nm.
The X-ray absorptive film 8 was formed to form a mask blank B for X-ray exposure of the present invention. (See FIG. 3 (c))

Subsequently, the backing mask 6 is formed by patterning the protective film 10 of a silicon carbide film using a photolithography method or the like, and using the back etching mask 6 as an etching mask, a concentration of 30% and a liquid temperature of 90%. The back surface of the frame substrate 9 was back-etched with an aqueous solution of potassium hydroxide at a temperature of 0 ° C. until the back surface of the frame substrate 9 reached the surface of the second antireflection film 4 to form the frame body 5 and the window 7. (See Fig. 6)

Subsequently, the X-ray absorbing film 8 is patterned using an electron beam lithography method or a photolithography method to provide a desired X-ray absorbing pattern film 1, whereby the X-ray exposure mask A of the present invention is provided. I got (See Fig. 1)

In the X-ray exposure mask A of the present invention thus manufactured, the second anti-reflection film 4 on the back surface of the X-ray transmission support film 3 is resistant to the etchant of the back etching. There is no need to go through the conventional dangerous process of forming the second anti-reflection film 4, and an X-ray exposure mask having the anti-reflection effect designed before the preparation of the X-ray exposure mask blank B is obtained. Was done.

<Embodiment 7> The size is 3 inches in diameter and the thickness is 1
mm on the surface (main surface) side of the silicon frame substrate 9.
A 50 nm tin oxide film is formed by a sputtering method,
A second anti-reflection film 4 of a tin oxide film was formed. (FIG. 3
(See (a))

Next, the front and back of the frame substrate 9 (main surface and back surface)
A silicon nitride film having a thickness of 2 μm was formed on both surfaces by a sputtering method to form an X-ray transmission support film 3 made of a silicon nitride film and a protective film 10 made of a silicon nitride film. (See FIG. 3B)

Then, a tin oxide film having a thickness of 150 nm is formed on the X-ray transmission supporting film 3 by a sputtering method to form a first anti-reflection film 2. The tantalum film by sputtering
An X-ray absorbing film 8 was formed. (FIG. 3 (c)
reference)

Subsequently, the backing mask 6 is formed by patterning the protective film 10 made of a silicon nitride film by using a photolithography method or the like, and a window is formed on the surface of the back etching mask 6 as a glass pedestal 11 in advance. The provided Pyrex glass is attached via an adhesive. (See Fig. 5)

Further, using the back etching mask 6 as an etching mask, a concentration of 30
%, By back-etching with a 90 ° C. aqueous solution of potassium hydroxide to form a frame 5 and a window 7,
A mask blank B for X-ray exposure of the present invention was obtained. (See Fig. 6)

Subsequently, the X-ray absorbing film 8 is patterned using an electron beam lithography method or a photolithography method to provide a desired X-ray absorbing pattern film 1, whereby the X-ray exposure mask A of the present invention is provided. I got (See Fig. 1)

In the mask A for X-ray exposure of the present invention thus manufactured, the second anti-reflection film 4 on the back surface of the X-ray transmission support film 3 is resistant to the etchant of the back etching. It is not necessary to go through the conventional dangerous process of forming the second anti-reflection film 4, and the X-ray exposure mask A having the anti-reflection effect as designed before the preparation of the X-ray exposure mask blank B is used. Obtained.

[0093]

The mask for X-ray exposure and the mask blank for X-ray exposure according to the present invention comprise at least a second anti-reflection film of a first anti-reflection film and a second anti-reflection film provided on both front and back surfaces of an X-ray transmissive support film. Since the anti-reflection film has sufficient resistance to a hot alkali solution, it is not etched or peeled during back etching, so that it can be used in a processing apparatus by peeling the second anti-reflection film. This has the effect of avoiding the risk of destruction of the X-ray transmission supporting film in the vacuum device.

The mask for X-ray exposure and the mask blank for X-ray exposure according to the present invention do not require replenishment of the second antireflection film on the back side of the X-ray transmission support film as in the prior art. There is no displacement of the X-ray absorbing pattern film due to the internal stress of the formed anti-reflection film and the like, and there is an effect of improving the positional accuracy of the X-ray exposure mask and the X-ray exposure mask blank.

[Brief description of the drawings]

FIG. 1 is a side sectional view of an embodiment of an X-ray exposure mask of the first invention.

FIG. 2 is a side sectional view of an embodiment of a mask blank for X-ray exposure according to the second invention.

3 (a) to 3 (d) are side sectional views sequentially showing manufacturing steps in an embodiment of the X-ray mask according to the first invention and an embodiment of the mask blank for X-ray exposure according to the second invention. FIG.

FIG. 4 is a side sectional view of another embodiment of the X-ray exposure mask of the first invention.

FIG. 5 is a side sectional view of another embodiment of the mask blank for X-ray exposure of the second invention.

FIG. 6 is a side sectional view of another embodiment of the mask blank for X-ray exposure of the second invention.

FIG. 7 is a side sectional view showing another embodiment of the mask blank for X-ray exposure according to the second invention.

FIG. 8 is a side sectional view illustrating an example of a conventional X-ray exposure mask.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... X-ray absorption pattern film 2 ... 1st anti-reflection film on the main surface side of X-ray support film 3 ... X-ray transmission support film 4 ... X-ray transmission support film back side anti-reflection film 5 ... Silicon frame 6 ... Back etching mask (etching resist pattern film) 7 ... Window 8 ... X-ray absorption film 9 ... Frame body substrate 10 ... Protective film 11 ... Glass base A ... X-ray exposure mask B ... X-ray exposure mask blank

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-8-51066 (JP, A) JP-A-6-61125 (JP, A) JP-A-5-315229 (JP, A) JP-A-5-315229 136030 (JP, A) JP-A-3-173638 (JP, A) JP-A-61-128251 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03F 1/00-1 / 16 H01L 21/027

Claims (14)

(57) [Claims] 1. A silicon frame 5 having a window 7 formed therein.
And an X-ray transmission supporting film 3 supported by the frame 5 and an X-ray absorbing pattern 1 made of heavy metal provided on the X-ray transmitting supporting film 3. In an X-ray exposure mask including a first antireflection film 2 between the X-ray transmission support film 3 and a second antireflection film 4 between the X-ray transmission support film 3 and the frame 5, The first consisting of elemental substances
An X-ray exposure apparatus comprising: an anti-reflection film 2, an X-ray transmission support film 3 made of a substance of a light element, and a second anti-reflection film 4 made of a tin oxide film resistant to a hot alkali solution. mask. 2. An X-ray exposure mask according to claim 1, wherein said first anti-reflection film 2 made of a substance of a light element is a tin oxide film. 3. An X-ray exposure mask according to claim 1, wherein said first antireflection film 2 made of a substance of a light element is an alumina film. 4. An X-ray exposure mask according to claim 1, wherein said first antireflection film 2 made of a substance of a light element is a silicon dioxide film. 5. An X-ray exposure mask according to claim 1, wherein said first antireflection film 2 made of a substance of a light element is a sialon film. 6. An X-ray exposure mask according to claim 1, wherein said X-ray transmission supporting film made of a light element substance is a silicon nitride film. 7. An X-ray exposure mask according to claim 1, wherein said X-ray transmission support film 3 made of a substance of a light element is a silicon carbide film. 8. A second antireflection film 4 made of a tin oxide film resistant to a hot alkali solution on a frame substrate 9 made of silicon.
And an X-ray transmission support film 3 made of a light element material, a first antireflection film 2 made of a light element material, and an X-ray
A mask blank for X-ray exposure, wherein the X-ray absorbing films 8 are provided in this order. 9. The mask blank for X-ray exposure according to claim 8, wherein said first anti-reflection film 2 made of a substance of a light element is a tin oxide film. 10. The mask blank for X-ray exposure according to claim 8, wherein said first anti-reflection film 2 made of a substance of a light element is an alumina film. 11. The mask blank for X-ray exposure according to claim 8, wherein said first antireflection film 2 made of a substance of a light element is a sialon film. 12. A mask blank for X-ray exposure according to claim 8, wherein said first antireflection film 2 made of a substance of a light element is a silicon dioxide film. 13. A mask blank for X-ray exposure according to claim 8, wherein said X-ray transmission supporting film 3 made of a substance of a light element is a silicon nitride film. 14. The mask blank for X-ray exposure according to claim 8, wherein said X-ray transmission support film 3 made of a substance of a light element is a silicon carbide film.