JP2003068615A - Transfer mask blank, manufacturing method therefor, transfer mask, manufacturing method therefor and exposure method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transfer mask blank that reduces positional distortions during a process and that of the blanks caused by resist stress, a manufacturing method therefor, a transfer mask, a manufacturing method therefor and an exposure method. SOLUTION: The transfer mask comprises a support substrate 27, a silicon thin film 24 on which a mask pattern is formed, and a thin film of rigidity higher than that of silicon that is so formed as to cover the supporting substrate 27 and a side surface thereof. It is desirable that this thin film of high rigidity be a diamond thin film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer mask blank used in a lithographic apparatus using a charged beam of electrons or ions in the manufacture of semiconductor integrated circuits,
The present invention relates to a manufacturing method, a transfer mask, a manufacturing method, and an exposure method.

[0002]

2. Description of the Related Art In recent years, with the high integration of integrated circuits, the photolithography technique using light, which has been the main means for forming fine patterns for many years, has been replaced by a charged particle beam such as an electron beam or an ion beam. A new exposure method using X-rays has been studied and put into practical use. Among them, the electron beam exposure for forming a pattern using an electron beam can reduce the electron beam itself to several nm, so
A major feature is that fine patterns of m or less can be produced.

However, since the conventional electron beam exposure method is a one-stroke writing method, it is necessary to draw with a narrowed electron beam as the pattern becomes finer. Therefore, the drawing time becomes long and the throughput is greatly affected.

Then, what has been devised is a method of exposing a partial portion collectively using a transfer mask. As this mask, a stencil type mask in which an opening for an electron beam transmitting portion is opened in a membrane-shaped silicon having a thickness of about 2 μm, or a membrane formed with a heavy metal or the like on a membrane-shaped silicon having a thickness of about 0.1 μm There are types of masks. At this time, the area exposed by the electron beam once is about 1 mm square, and therefore, in order to burn the entire semiconductor chip, a membrane of about 1 mm square must be spread.

FIG. 3 is a plan view showing a transfer mask.
This transfer mask is manufactured using an 8-inch wafer. The wafer 11 has a lattice structure processing section 12 in which a lattice structure having a size of 132 mm × 55 mm is processed.
Are formed side by side.

These masks are generally manufactured by the following method. 4A to 4E are cross-sectional views showing a method for producing a mask blank and a transfer mask made of a silicon thin film. It should be noted that FIG. 4 shows one 1 mm square window of the mask for simplification of the drawing.

First, as shown in FIG. 4 (a), a silicon support substrate 1 and a silicon oxide layer 3 formed thereon.
An SOI (silicon on insulator) wafer 10 composed of a silicon active layer 2 formed on the silicon active layer 2 is prepared. The silicon active layer 2 is a layer on which a silicon membrane is formed.

After that, as shown in FIG. 4B, impurities such as phosphorus, boron, and carbon are introduced into the silicon active layer 2. As a result, the silicon thin film layer 4 with impurities added is formed on the silicon oxide layer 3. Figure 4
Since the silicon active layer 2 of the SOI wafer shown in (a) has a compressive stress, it is loosened when it is made into a self-supporting thin film. Therefore, by adding an impurity such as phosphorus to the silicon active layer 2, the stress of the silicon thin film layer 4 serving as the silicon membrane is reduced to some extent by a tensile stress (for example, 1
It is controlled to about 0 MPa).

Next, as shown in FIG. 4C, a resist film as a mask material for silicon etching is applied on the main surface (lower surface) of the silicon supporting substrate 1. Then, the resist film 5 is subjected to a photolithography process to form a resist pattern 5 on the main surface of the silicon supporting substrate 1.

After that, as shown in FIG. 4D, the silicon support substrate 1 is etched using the resist pattern 5 as a mask and the silicon oxide layer 3 as an etching stop layer. As a result, the etching is stopped on the silicon oxide layer 3, and the lattice-shaped support portion 7 made of a silicon support substrate is formed on the silicon oxide layer 3.

Next, as shown in FIG. 4E, since the silicon oxide layer 3 below the portion where the silicon self-supporting thin film is formed is unnecessary, the resist pattern 5 is used as a mask and the silicon thin film layer 4 is removed. The silicon oxide layer 3 is removed by etching as an etching stop layer. Then, the resist pattern 5 is peeled off. In this way, the transfer mask blanks 13 are completed.

Next, a resist film (not shown) is applied on the silicon thin film layer 4, and the pattern of the transfer mask is exposed and developed on the resist film by using an electron beam drawing apparatus or the like. As a result, a resist pattern is formed on the silicon thin film layer 4. Next, the stencil pattern is formed on the silicon membrane (silicon thin film layer) by etching the silicon thin film layer 4 using this resist pattern as a mask. In this way, a transfer mask (not shown) as a transfer mask is completed.

Although the above-mentioned conventional transfer mask blanks use the SOI wafer, it is also possible to use a silicon wafer doped with boron. However,
Since the high-concentration silicon layer serves as an etching stop layer to form a membrane, the silicon wafer does not have a silicon oxide layer serving as an etching stop layer.

[0014]

In the transfer mask as described above, most of the wafer 11 is removed by etching when the lattice structure processed portion 12 is formed as shown in FIG. Therefore, although there is a grid-like support,
The rigidity of the transfer mask itself is much smaller than that of a conventional glass reticle that is exposed using light. As a result, since the warp is much larger than that of the glass reticle, a large chucking distortion may occur when the transfer mask is mounted on an electron beam exposure device (EB stepper) or the like (during chucking). The chucking method is often different for each process step, but if the rigidity of the transfer mask itself is low, the entire transfer mask may be deformed depending on the chucking method, which may cause positional distortion.

Further, in the above transfer mask, a large positional distortion may occur during the process. FIG. 5 (a)-
FIG. 6C is a cross-sectional view illustrating a cause of positional distortion during the process.

In the blanks 13 after the back etching shown in FIG. 5A, a resist film 15 for drawing a fine pattern is applied on the membrane 4 as shown in FIG. 5B. At this time, since the resist film 15 has a tensile stress, the entire blank 13 shrinks due to the tensile stress. In this state, the resist film 15 is exposed and developed to draw a fine pattern, and thereafter,
Using the resist film 15 as a mask, the membrane 4 is etched to draw a fine pattern.

Next, as shown in FIG. 5C, when the resist film 15 is removed, the blanks 13 which have been shrunk by the tensile stress of the resist film 15 are in a state before the resist film is applied (the state of FIG. 5A). ) Return to. As a result, positional distortion occurs by the amount of change 16 from the state in which the fine pattern is drawn to the state in which the resist film is removed.

The present invention has been made in consideration of the above circumstances, and an object thereof is a transfer mask blank which can reduce the occurrence of positional distortion of the blank due to positional distortion during the process or resist stress, and a manufacturing method thereof. The present invention provides a transfer mask, a manufacturing method thereof, and an exposure method.

[0019]

In order to solve the above problems, a transfer mask blank according to the present invention is a transfer mask blank including a support substrate and a silicon thin film on which a mask pattern is formed. It is characterized by comprising a thin film having a rigidity higher than that of silicon formed so as to cover side surfaces of the substrate and its supporting substrate. In addition, in the transfer mask blank according to the present invention, it is preferable that the high-rigidity thin film is a diamond thin film.

According to the above transfer mask blank, the support substrate and the thin film having higher rigidity than silicon are formed so as to cover the side surface of the support substrate. Therefore, the rigidity of the entire transfer mask blank can be enhanced as compared with the conventional transfer mask blanks.

A method of manufacturing a transfer mask blank according to the present invention is a method of manufacturing a transfer mask blank including a support substrate and a silicon thin film on which a mask pattern is formed, which comprises a silicon support substrate and a silicon oxide layer. And a step of preparing an SOI substrate including a silicon thin film, and
I step of forming a high-rigidity thin film on all of the upper surface, lower surface, and side surface of the substrate, on the silicon thin film in the portion where the mask pattern is formed, and on the portion other than the portion to be the supporting substrate, respectively. The step of removing the highly rigid thin film, the step of forming the supporting substrate by etching the silicon supporting substrate with the highly rigid thin film as the mask and the silicon oxide layer as the etching stop layer, and the highly rigid thin film as the mask Etching the silicon oxide layer,
It is characterized by including.

A method of manufacturing a transfer mask blank according to the present invention is a method of manufacturing a transfer mask blank including a support substrate and a silicon thin film on which a mask pattern is formed, which is a step of preparing a silicon substrate. A step of forming an impurity introduction layer in the silicon substrate by introducing impurities into the surface of the silicon substrate, and a step of forming a highly rigid thin film on all of the upper surface, the lower surface and the side surface of the silicon substrate. A step of removing the high-rigidity thin film on the impurity introduction layer in the portion where the mask pattern is formed, and on the silicon substrate other than the portion to be the support substrate, and A step of forming columns of the supporting substrate by digging from the backside by dry etching, and using the high-rigidity thin film as a mask and etching the impurity introduction layer. Characterized by comprising the steps of a silicon substrate is wet-etched as ring stop layer.

The transfer mask according to the present invention comprises a support substrate,
A transfer mask comprising a silicon thin film having a mask pattern formed thereon, comprising a support substrate and a thin film having a higher rigidity than silicon formed so as to cover a side surface of the support substrate. Further, in the transfer mask according to the present invention, it is preferable that the high-rigidity thin film is a diamond thin film.

According to the above transfer mask, a highly rigid thin film is formed so as to cover the supporting substrate and the side surface of the supporting substrate. Therefore, the rigidity of the entire transfer mask can be enhanced as compared with the conventional transfer mask.

A method of manufacturing a transfer mask according to the present invention comprises a support substrate, a silicon thin film on which a mask pattern is formed,
A method for manufacturing a transfer mask comprising: a silicon support substrate, a silicon oxide layer, and a silicon thin film.
A step of preparing an OI substrate, an upper surface and a lower surface of the SOI substrate,
The step of forming a high-rigidity thin film on all of the side surfaces, and removing the high-rigidity thin film on each of the silicon thin film on the portion where the mask pattern is formed and on the portion other than the portion to be the supporting substrate A step of forming a support substrate by etching the silicon support substrate using the high rigidity thin film as a mask and a silicon oxide layer as an etching stop layer; and a step of etching the silicon oxide layer using the high rigidity thin film as a mask And a step of forming a mask pattern on the silicon thin film.

According to the method of manufacturing the transfer mask described above, SO
A high-rigidity thin film is formed on the entire surface of the I substrate, and the high-rigidity thin film is removed on the silicon thin film where the mask pattern is to be formed and on the portion other than the portion that will be the support substrate. Therefore, the rigidity of the entire transfer mask can be enhanced as compared with the conventional transfer mask. This makes it possible to suppress the occurrence of chucking distortion when the transfer mask is chucked in the exposure apparatus. Further, in the state of the transfer mask blank, a high-rigidity thin film is formed so as to cover the supporting substrate and the side surface of the supporting substrate in the blank. Therefore, even when a tensile stress is applied to the transfer mask blanks by the resist film when a resist film is applied on the silicon thin film to form a mask pattern, it is possible to prevent the blanks from shrinking as a whole. it can. As a result, it is possible to reduce the occurrence of positional distortion of the blanks due to resist stress during the process.

A transfer mask manufacturing method according to the present invention comprises a support substrate, a silicon thin film on which a mask pattern is formed,
A method of manufacturing a transfer mask comprising: a step of preparing a silicon substrate; a step of introducing an impurity into a surface of the silicon substrate to form an impurity introduction layer on the silicon substrate; A step of forming a high-rigidity thin film on all surfaces of the upper surface, the lower surface, and the side surface, on the impurity introduction layer in the portion where the mask pattern is formed, and
A step of removing the high-rigidity thin film on each of the silicon substrates other than the portion to be the support substrate, and a step of forming columns of the support substrate by digging by dry etching from the back surface of the silicon substrate using the high-rigidity thin film as a mask When,
The method is characterized by including a step of wet-etching a silicon substrate using a highly rigid thin film as a mask and an impurity introduction layer as an etching stop layer, and a step of forming a mask pattern on the silicon thin film.

In the exposure method according to the present invention, the charged particle beam is guided to the transfer mask by the illumination system, and the charged particle beam from the transfer mask is guided to the photosensitive substrate by the projection optical system, whereby the pattern of the transfer mask is made photosensitive. An exposure method for transferring onto a substrate, wherein the transfer mask comprises a support substrate and a silicon thin film on which a mask pattern is formed, and the transfer mask is higher than the silicon formed so as to cover a side surface of the support substrate. It is characterized by having a rigid thin film.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1A to 1C are cross-sectional views showing a method of manufacturing a transfer mask according to the first embodiment of the present invention. It should be noted that FIG. 1 shows one 1 mm square window of the mask for the sake of simplification of the drawing.

First, as shown in FIG. 1A, a silicon support substrate 21 and a silicon oxide layer 2 formed on the silicon support substrate 21.
An SOI (silicon on insulator) wafer 30 including 3 and a silicon active layer formed thereon is prepared. The silicon active layer is a layer on which a silicon membrane is formed.

Then, phosphorus, boron,
Introduce impurities such as carbon. As a result, a silicon thin film layer 24 having impurities added is formed on the silicon oxide layer 23. Since the silicon active layer of the SOI wafer has a compressive stress, it is loosened when it is made into a self-supporting thin film. Therefore, by adding impurities such as phosphorus to the silicon active layer, the stress of the silicon thin film layer 24 serving as the silicon membrane is controlled to a certain degree of tensile stress (for example, about 10 MPa).

Then, a diamond thin film 25, which is a highly rigid thin film having a thickness of about 1 to 10 μm, is formed on all the upper, lower and side surfaces of the SOI wafer 30 by CVD (Chemical).
It is formed by the Vapor Deposition method.

After that, as shown in FIG. 1B, the diamond thin film in the portion where the drawing pattern is formed on the membrane is removed. Further, the diamond thin film other than the portion to be the lattice-shaped support portion 27 of the silicon support substrate 21 is also removed.
As a removing method here, a resist film (not shown) is applied on the diamond thin film 25, and the resist film is exposed and
There is a method of developing and forming a resist pattern on the diamond thin film, and then removing the diamond thin film by etching using the resist pattern as a mask.

Next, as shown in FIG. 1C, the diamond thin film 25 is used as a mask and the silicon oxide layer 23 is used.
Is used as an etching stop layer to dry-etch the silicon support substrate 21. As a result, the silicon oxide layer 2
Etching is stopped at 3 and a lattice-shaped supporting portion 27 made of a silicon supporting substrate is formed on the silicon oxide layer 23.

Next, since the silicon oxide layer 23 under the portion where the silicon self-supporting thin film is formed is unnecessary, the diamond thin film 25 is used as a mask and the silicon thin film layer 2 is used.
The silicon oxide layer 23 is removed by etching using 4 as an etching stop layer. Thus, the mask blank for transfer is completed.

Next, a resist film (not shown) is applied on the silicon thin film layer 24, and the pattern of the transfer mask is exposed and developed on the resist film by using an electron beam drawing apparatus or the like. As a result, a resist pattern is formed on the silicon thin film layer 24. Then, the silicon thin film layer 24 is etched by using this resist pattern as a mask to form a penetrating pattern (stencil pattern) in the silicon membrane (silicon thin film layer). In this way, the transfer mask 31 for the EB stepper is completed.
Further, instead of the stencil pattern, it is also possible to use a membrane type transfer mask in which a pattern is formed of a heavy metal or the like on a silicon membrane.

Next, an exposure method for exposing the sensitive substrate using the transfer mask shown in FIG. 1C will be described.

First, a sensitive substrate having a resist film coated on the wafer is prepared, and the sensitive substrate is placed on the substrate stage of the EB stepper. Next, a transfer mask 31 shown in FIG. 1C is prepared, and the transfer mask 31 is set to E
Installed by chucking on the B stepper.

Then, the electron beam is guided to the transfer mask 31 by the illumination system, and the electron beam from the transfer mask 31 is guided to the photosensitive substrate by the projection optical system to transfer the mask 3.
The pattern 1 is transferred to the photosensitive substrate. Then, the transfer pattern of the transfer mask is transferred to the sensitive substrate by developing the sensitive substrate.

According to the first embodiment described above, the diamond thin film 25, which is a thin film having high rigidity, is formed so as to cover the lattice-shaped support portion 27 and the side surface of the mask in the transfer mask. Therefore, the rigidity of the entire mask can be enhanced as compared with the conventional transfer mask. That is, even in a transfer mask having low rigidity, by forming a thin film having high rigidity on both surfaces of the mask, it becomes possible to increase the rigidity of the entire mask. Accordingly, when the transfer mask is chucked by the EB stepper, it is possible to suppress the occurrence of chucking distortion. Therefore, it becomes possible to supply a high-performance transfer mask with little positional distortion.

In the first embodiment, the diamond thin film 25, which is a high-rigidity thin film, is formed so as to cover the lattice-shaped support portions 27 of the transfer mask blank and the side surfaces of the mask blank in the state of the transfer mask blank. There is. Therefore, the rigidity of the entire mask blank can be enhanced as compared with the conventional transfer mask blank. Therefore, when a resist film is applied on the membrane to form a transfer pattern on the membrane, even if tensile stress is applied to the transfer mask blanks by the resist film, shrinkage of the entire blanks can be suppressed. As a result, it is possible to reduce the occurrence of positional distortion of the blanks due to resist stress during the process. Therefore,
It is possible to supply a high-performance transfer mask with little positional distortion.

FIGS. 2A to 2C show a second embodiment of the present invention.
FIG. 9 is a cross-sectional view showing the method of manufacturing the transfer mask according to the embodiment of the present invention, which uses boron-doped silicon.

First, as shown in FIG. 2A, the surface of the silicon wafer 34 is doped with boron to form a boron-doped layer 33. Then, a diamond thin film 25, which is a highly rigid thin film having a thickness of about 1 to 10 μm, is formed on all the upper, lower and side surfaces of the silicon wafer 34 by the CVD method.

After that, as shown in FIG. 2B, the diamond thin film in the portion where the drawing pattern is formed on the membrane is removed. Also, the lattice-shaped support portion 3 of the silicon wafer
The diamond thin film other than the portion to be 7 is also removed. The removing method here is the same as that in the first embodiment.

Next, by using the diamond thin film 25 as a mask, a vertical pillar is formed by digging from the back surface of the silicon wafer 34 to a point of a predetermined thickness of several tens of μm by dry etching.

Next, as shown in FIG. 2C, wet etching is used only at the end to stop the etching with a membrane having a predetermined thickness. The diamond thin film 25 is covered except where it is etched. In this way, the lattice-shaped support portion 37 is formed.

Next, a resist film (not shown) is applied on the boron-doped layer 33, and the pattern of the transfer mask is exposed and developed on the resist film by using an electron beam drawing device or the like. As a result, a resist pattern is formed on the boron-doped layer 33. Then, the boron-doped layer 33 is etched by using this resist pattern as a mask to form a penetrating pattern (stencil pattern) on the silicon membrane (boron-doped layer). In this way, a transfer mask (not shown) for the EB stepper is completed. Further, as in the first embodiment, a membrane type transfer mask can be used.

Since the exposure method for exposing the sensitive substrate using the transfer mask shown in FIG. 2C is the same as that in the first embodiment, the description thereof will be omitted.

In the second embodiment, the same effect as in the first embodiment can be obtained. That is,
A diamond thin film 25 which is a thin film having high rigidity so as to cover the lattice-shaped support portion 37 and the side surface of the mask in the transfer mask
Is formed. Therefore, the rigidity of the entire mask can be enhanced as compared with the conventional transfer mask. Accordingly, when the transfer mask is chucked by the EB stepper, it is possible to suppress the occurrence of chucking distortion.

In the second embodiment, the diamond thin film 25, which is a highly rigid thin film, is formed so as to cover the lattice-shaped support portions 37 and the side surfaces of the mask blanks in the transfer mask blanks in the state of the transfer mask blanks. There is. Therefore, the rigidity of the entire mask blank can be enhanced as compared with the conventional transfer mask blank. Therefore, the occurrence of positional distortion of the blanks due to resist stress during the process can be reduced.

The present invention is not limited to the above embodiment, but can be implemented with various modifications. For example,
In the above embodiment, the diamond thin film formed by the CVD method is used, but the present invention is not limited to this, and any other thin film can be used as long as it has a rigidity higher than that of silicon.

[0052]

As described above, according to the present invention, a thin film having a rigidity higher than that of silicon is formed so as to cover the supporting substrate and the side surface of the supporting substrate. Therefore, it is possible to provide a transfer mask blank, a manufacturing method thereof, a transfer mask, a manufacturing method thereof, and an exposure method capable of reducing the occurrence of the positional distortion of the blank due to the positional distortion during the process and the resist stress.

[Brief description of drawings]

1A to 1C are cross-sectional views showing a method of manufacturing a transfer mask according to a first embodiment of the present invention.

2A to 2C are cross-sectional views showing a method of manufacturing a transfer mask according to a second embodiment of the present invention,
It is made of boron-doped silicon.

FIG. 3 is a plan view showing a transfer mask.

4A to 4E are cross-sectional views showing a method for producing a mask blank and a transfer mask made of a silicon thin film.

5A to 5C are cross-sectional views illustrating a cause of positional distortion during a process.

[Explanation of symbols]

1, 21 ... Silicon support substrate 2 ... Silicon active layer 3, 23 ... Silicon oxide layer 4, 24 ... Silicon thin film layer 5 ... Resist pattern 7, 27, 37
Lattice-shaped support portion 10 ... SOI wafer 11 ... Wafer 12 ... Lattice structure processing portion 13 ... Mask blanks 15 ... Resist film 16 ... Change amount 25 ... Diamond thin film 30 ... SOI wafer 31 ... Transfer mask 33 ... Boron-doped layer 34 ... Silicon wafer

Claims (9)

[Claims] 1. A transfer mask blank comprising a supporting substrate and a silicon thin film on which a mask pattern is formed, the thin film having a rigidity higher than that of silicon formed so as to cover the supporting substrate and a side surface of the supporting substrate. A transfer mask blanks comprising: 2. The transfer mask blanks according to claim 1, wherein the highly rigid thin film is a diamond thin film. 3. A method for manufacturing a transfer mask blank comprising a support substrate and a silicon thin film on which a mask pattern is formed, which comprises preparing an SOI substrate including a silicon support substrate, a silicon oxide layer and a silicon thin film. A step of forming a high-rigidity thin film on all of the upper surface, lower surface, and side surface of the SOI substrate, and a silicon thin film in a portion where the mask pattern is formed,
And a step of removing the high-rigidity thin film on each part other than the part to be the support substrate, and the support substrate by etching the silicon support substrate using the high-rigidity thin film as a mask and the silicon oxide layer as an etching stop layer. And a step of etching the silicon oxide layer using a high-rigidity thin film as a mask, the method of manufacturing a transfer mask blanks. 4. A method of manufacturing a transfer mask blank comprising a support substrate and a silicon thin film on which a mask pattern is formed, the method comprising the steps of preparing a silicon substrate and introducing impurities into the surface of the silicon substrate. By doing so, a step of forming an impurity introduction layer on the silicon substrate, a step of forming a high-rigidity thin film on all of the upper surface, lower surface, and side surfaces of the silicon substrate, and a step of forming the mask pattern are performed. On the impurity introduction layer,
And a step of removing the high-rigidity thin film on each of the silicon substrates other than the part to be the support substrate, and forming columns of the support substrate by digging from the back surface of the silicon substrate by dry etching using this high-rigidity thin film as a mask And a step of wet-etching the silicon substrate using the highly rigid thin film as a mask and the impurity introduction layer as an etching stop layer. 5. A transfer mask comprising a support substrate and a silicon thin film on which a mask pattern is formed, the transfer mask comprising a support substrate and a thin film having a rigidity higher than that of silicon formed so as to cover a side surface of the support substrate. A transfer mask comprising: 6. The transfer mask according to claim 5, wherein the high-rigidity thin film is a diamond thin film. 7. A method of manufacturing a transfer mask comprising a support substrate and a silicon thin film on which a mask pattern is formed, the step of preparing an SOI substrate including a silicon support substrate, a silicon oxide layer and a silicon thin film. And a step of forming a high-rigidity thin film on all of the upper surface, lower surface, and side surface of the SOI substrate, and on the silicon thin film where the mask pattern is formed,
And a step of removing the high-rigidity thin film on each part other than the part to be the support substrate, and the support substrate by etching the silicon support substrate using the high-rigidity thin film as a mask and the silicon oxide layer as an etching stop layer. And a step of etching the silicon oxide layer with a high-rigidity thin film as a mask, and a step of forming a mask pattern on the silicon thin film. 8. A method of manufacturing a transfer mask comprising a support substrate and a silicon thin film on which a mask pattern is formed, the method comprising the steps of preparing a silicon substrate and introducing impurities into the surface of the silicon substrate. By doing so, a step of forming an impurity introduction layer on the silicon substrate, a step of forming a high-rigidity thin film on all of the upper surface, lower surface, and side surfaces of the silicon substrate, and impurities in the portion where the mask pattern is formed On the introduction layer,
And a step of removing the high-rigidity thin film on each of the silicon substrates other than the part to be the support substrate, and forming columns of the support substrate by digging from the back surface of the silicon substrate by dry etching using this high-rigidity thin film as a mask And a step of wet etching the silicon substrate using the highly rigid thin film as a mask and the impurity introduction layer as an etching stop layer, and a step of forming a mask pattern in the silicon thin film. Manufacturing method. 9. An exposure method for transferring a pattern of a transfer mask to a photosensitive substrate by guiding the charged particle beam to a transfer mask by an illumination system and guiding the charged particle beam from the transfer mask to a photosensitive substrate by a projection optical system. The transfer mask includes a support substrate and a silicon thin film on which a mask pattern is formed, and includes the support substrate and a thin film having higher rigidity than silicon formed to cover the side surface of the support substrate. An exposure method characterized by the above.