JP2001015424A - Transfer mask, device and structure for holding mask - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid generation of bends in the center of a transfer mask main body and to sufficiently suppressing the vibration of the transfer mask main body, concerning a transfer mask to be used at pattern transfer, in the manufacturing process of a semiconductor. SOLUTION: Surrounding of a transfer mask main body 13, having plural transferring areas 13A divided in the state of blocks is held by a retaining ring 15. The neighborhood of the center of the main body 13 is supported by a supporter 18 in the state of detachable beam from the side of its lower surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer mask, a mask holding device, and a mask holding structure, and more particularly, to a transfer mask used for transferring a pattern in a semiconductor manufacturing process and a mask holding a transfer mask body. The present invention relates to an apparatus and a mask holding structure for holding a transfer mask body.

[0002]

2. Description of the Related Art As a system for transferring a pattern onto a semiconductor wafer, a partial batch direct writing system and a projection type electron beam writing system are known. The partial batch direct writing method is a method in which a part of a pattern included in one semiconductor chip is transferred by projection and the remaining part is transferred by variable molding. The projection type electron beam writing method is a method of transferring a pattern included in one semiconductor chip by dividing the pattern into a plurality of block-like transfer regions. According to the projection type electron beam writing method, a higher throughput can be obtained as compared with the partial collective direct writing method, and there is an advantage that data processing required in the partial collective direct writing method is not required.

FIG. 3 is a conceptual diagram for explaining an outline of a conventional projection type electron beam writing system. In FIG. 3, 41
Is an electron source that emits electrons. An upper mask 42 having an aperture 42A is disposed below the electron source 41. The electron beam 41A emitted from the electron source 41 passes through the aperture 42A of the upper mask 42 to form a shaped beam 41B.

[0004] Below the upper mask 42, a forming beam 4 is provided.
A deflector 44 for applying an electric field to 1B is arranged. Further, below the deflector 44, a transfer mask 43 provided with a pattern included in one semiconductor chip divided into a plurality of transfer regions 43A is provided. Aperture 4
The shaped beam 41B that has passed through 2A is deflected by the deflector 44 and is applied to an appropriate transfer area 43A on the transfer mask 43. The transfer mask 43 is held by a holding stage 45 by a mask stage (not shown) of the drawing apparatus.
It is fixed to. Electrons 41 that have passed through transfer mask 43
C denotes the wafer 4 mounted on the wafer stage 46
7 is irradiated.

As described above, in the projection type electron beam writing system, the transfer mask 4 provided with the pattern included in one chip divided into several transfer regions 43A.
3 is used. The transfer magnification used in the projection type electron beam writing method is about several times (4 to 6 times). However, if the chip area to be drawn becomes large, the pattern is divided on the transfer mask 43 by the division of the pattern. The formed region (hereinafter, referred to as “mask region”) becomes large.

FIG. 4 is a plan view of a conventional transfer mask (FIG. 4).
(A)) and a side view (FIG. 4 (b)). In FIG. 4, reference numeral 33 denotes a transfer mask main body, 33A denotes a transfer area where a desired pattern is formed, and 35 denotes a holding ring that supports the entire mask. Reference numeral 36 denotes a transfer mask including the transfer mask body 33 and the holding ring 35. A transfer mask for electron beams, that is, EB (Elec
The tro beam) mask is usually made of a thin material such as a Si wafer. A holding ring is provided around the EB mask so as to secure its mechanical strength and at the same time, to serve as a fixed portion to the mask stage.

[0007]

However, if the transfer mask body 33 is required to have a large diameter of, for example, about 8 inches, the thickness of the transfer mask 36 cannot be increased due to processing restrictions. There are times when we cannot secure enough. In this case, as shown in FIG. 4B, deflection due to its own weight occurs near the center of the transfer mask 36. If the transfer mask 36 is bent, accurate pattern transfer becomes difficult, and a dimensional deviation or a positional deviation occurs in the pattern on the wafer.

The mask stage on which the transfer mask 36 is fixed moves at a high speed several times as fast as the wafer stage on which the wafer is placed. For this reason, vibration may occur in the transfer mask 36 during the pattern transfer. When such vibrations occur in the transfer mask main body 33, there is a problem that the resolution is deteriorated and the pattern transfer accuracy is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and does not cause the central portion of the transfer mask body to bend, and can sufficiently suppress the vibration of the transfer mask body. A first object is to provide a transfer mask. It is a second object of the present invention to provide a mask holding device capable of compensating for the deflection generated at the center of the transfer mask main body and reducing the vibration of the transfer mask main body. It is a third object of the present invention to provide a mask holding structure capable of compensating for the deflection generated at the center of the transfer mask main body and reducing the vibration of the transfer mask main body.

[0010]

According to a first aspect of the present invention, there is provided a transfer mask body having a plurality of transfer areas divided into blocks and holding a periphery of the transfer mask body. A transfer ring having a detachable support near the center of the transfer mask main body and coming into contact with the lower surface thereof.

According to a second aspect of the present invention, there is provided the transfer mask according to the first aspect, further comprising a detachable second support which is in contact with a central portion of the transfer mask main body from an upper surface thereof. Features.

According to a third aspect of the present invention, there is provided a mask holding apparatus for holding a transfer mask main body having a plurality of transfer regions divided into blocks, the detachable holding unit holding the periphery of the transfer mask main body. A holding ring; and a detachable support that comes into contact with a vicinity of a central portion of the transfer mask main body.

According to a fourth aspect of the present invention, there is provided the mask holding apparatus according to the third aspect, wherein the detachable second support comes into contact with the vicinity of the center of the transfer mask main body from the side opposite to the support. It is characterized by having.

According to a fifth aspect of the present invention, there is provided a mask holding structure for holding a transfer mask main body having a plurality of transfer regions divided in a block shape, wherein the transfer mask main body has a lower surface near a central portion thereof. It is characterized in that a support detachable from the side is brought into contact.

Further, according to a sixth aspect of the present invention, in the mask holding structure according to the fifth aspect, a detachable second support is brought into contact with a vicinity of a central portion of the transfer mask main body from a side opposite to the support. It is characterized by making it.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a plan view (FIG. 1A) and a side view (FIG. 1B) of the transfer mask of the present embodiment. In FIG. 1, reference numeral 11 denotes a transfer mask of the present embodiment. The transfer mask 11 is a mask used in a drawing device of a projection electron beam drawing system, and includes a transfer mask main body 13, a holding ring 15, and a beam-shaped support 18, which is a main part of the present invention.

The transfer mask body 13 is made using an 8-inch Si wafer. In the transfer mask body 13,
A plurality of transfer areas 13A each having a desired pattern
Is provided. The transfer region 13A is a part of a pattern included in one chip to be formed on a semiconductor wafer. When all the transfer areas 13A formed on the transfer mask body 13 are transferred onto the wafer without gaps, a pattern for one chip can be transferred onto the wafer.

The holding ring 15 increases the mechanical strength of the transfer mask body 13 by holding the periphery thereof, and serves as a fixing portion when the transfer mask 11 is fixed to a mask stage (not shown) of the drawing apparatus. Part. The holding ring 15 is provided detachably with respect to the transfer mask body 13.

The beam-shaped support 18 is fixed to the holding ring 15 so as to extend in two directions passing through the center of the transfer mask main body 13, specifically, in two orthogonal directions corresponding to the XY directions of the mask stage. ing. In addition, the beam-shaped support 18
The entire surface is formed so as to contact the lower surface of the transfer mask body 13. The beam-shaped support 18 has excellent heat conductivity,
And it is made of a material having high hardness, specifically, diamond, tungsten, or various ceramics.

In the present embodiment, a mask holding device is realized by the holding ring 15 and the support 18.
The transfer mask 11 is realized by holding the transfer mask body 13 by the mask holding device.
According to the above-described mask holding device, a sufficiently large mechanical strength can be imparted to the transfer mask 11. For this reason, the deflection of the transfer mask 11 due to its own weight and the vibration of the transfer mask 11 due to the high-speed movement of the mask stage can be suppressed. Therefore, according to the transfer mask 11 of the present embodiment, highly accurate pattern transfer can be realized.

Embodiment 2 FIG. Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a plan view (FIG. 2A) and a side view (FIG. 2B) of the transfer mask of the present embodiment. In FIG. 2, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 2, reference numeral 21 denotes a transfer mask of the present embodiment. The transfer mask 21 includes a transfer mask body 13 and a holding ring 15, and two beam-shaped supports 28 provided above and below the transfer mask body 13. Support 28
Are made of the same material as that of the support 18 in the first embodiment, and are provided so as to extend in two directions passing through the center of the transfer mask body 13 (two orthogonal directions corresponding to the XY directions of the mask stage). It is fixed to. In the present embodiment, the beam-shaped support 28 is formed such that the entire surface thereof contacts the upper or lower surface of the transfer mask body 13.

In this embodiment, a mask holding device is realized by the holding ring 15 and the two supports 28. The transfer mask 21 is realized by holding the transfer mask body 13 by the mask holding device. According to the above mask holding device, the deflection of the transfer mask 21 due to its own weight can be suppressed sufficiently small, and the vibration accompanying the high-speed operation of the mask stage can be suppressed sufficiently small. For this reason, according to the transfer mask 21 of the present embodiment, it is possible to realize pattern transfer with higher accuracy than in the case of the first embodiment.

Incidentally, in the first or second embodiment described above,
In the above, the beam-shaped supports 18, 28 are fixed to the holding ring 15, but the present invention is not limited to this. That is, the supports 18, 28 and the holding ring 15 may be formed separately. When such a configuration is adopted, for example, the transfer mask body 13 held by the holding ring 15
When mounting on the mask stage,
28 can realize the state shown in FIG. 1 or FIG. In this case, the support 18 or 28 becomes a mask holding device.

In the first or second embodiment, the beam-shaped supports 18, 28 are provided so as to extend in two orthogonal directions. However, the present invention is not limited to this. Instead, the supports 18 and 28 may be provided only in any direction.

In the first or second embodiment described above, only one support 18, 28 is provided in one direction. However, the present invention is not limited to this, and a plurality of supports 18 and 28 may be provided in the same direction. A main support may be provided.

Furthermore, in the first or second embodiment described above, the supports 18, 28 are in contact with the transfer mask body 13 on the entire surface, but the present invention is not limited to this. It is sufficient that 28 is in contact with at least the vicinity of the center of the transfer mask body 13.

In the first embodiment, the support 18
Corresponds to the “support” of the first, third or fifth aspect. In the above-described second embodiment, the support 28 that contacts the lower surface of the transfer mask main body 13 corresponds to the “support” according to claim 1, 3, or 5, and the support 28 that contacts the upper surface of the transfer mask main body 13 includes the support 28. The second support corresponds to the “second support” according to the second, fourth, or sixth aspect.

[0029]

According to the first, third, or fifth aspect of the present invention, the vicinity of the center of the transfer mask main body can be supported from the lower surface side. Therefore, according to the present invention, it is possible to increase the mechanical strength of the transfer mask main body and suppress the deflection of the transfer mask main body due to its own weight and the vibration of the transfer mask main body due to the movement of the mask stage. Therefore, according to the present invention, highly accurate pattern transfer can be realized.

According to the second, fourth, or sixth aspect of the present invention, the vicinity of the center of the transfer mask main body can be supported from both the lower surface and the upper surface. Therefore, according to the present invention, the mechanical strength of the transfer mask main body can be further increased as compared with the case where the transfer mask main body is supported only from the lower surface side. Therefore, according to the present invention, claims 1, 3 or 5
The pattern transfer with higher accuracy can be realized as compared with the case of

[Brief description of the drawings]

FIG. 1 is a plan view and a side view illustrating a structure of a transfer mask according to a first embodiment of the present invention.

2A and 2B are a plan view and a side view illustrating a structure of a transfer mask according to a second embodiment of the present invention.

FIG. 3 is a conceptual diagram for explaining a method of transferring a pattern by a projection electron beam drawing method.

FIG. 4 is a plan view and a side view showing the structure of a conventional transfer mask.

[Explanation of symbols]

 11, 21 Transfer mask 13 Transfer mask body 13A Transfer area 15 Retaining ring 18, 28 Support 41 Electron source 41A, 41C Electron 41B Shaping beam 42 Upper mask 42A Upper mask aperture 44 Deflector

Claims (6)

[Claims] 1. A transfer mask main body having a plurality of transfer regions divided in a block shape, a holding ring for holding a periphery of the transfer mask main body, and a contact near a center portion of the transfer mask main body from a lower surface side thereof. A transfer mask, comprising: a detachable support; 2. The transfer mask according to claim 1, further comprising a detachable second support that comes into contact with the transfer mask main body near the center from the upper surface side. 3. A mask holding device for holding a transfer mask main body having a plurality of transfer areas divided into blocks, comprising: a detachable holding ring for holding a periphery of the transfer mask main body; and the transfer mask main body. And a detachable support that comes into contact with the vicinity of the central portion of the mask holding device. 4. The mask holding apparatus according to claim 3, further comprising a detachable second support which comes into contact with a vicinity of a central portion of the transfer mask main body from a side opposite to the support. 5. A mask holding structure for holding a transfer mask main body having a plurality of transfer regions divided in a block shape, wherein a support detachable from a lower surface side of the transfer mask main body is contacted near a central portion of the transfer mask main body. And a mask holding structure. 6. The mask holding structure according to claim 5, wherein a detachable second support is brought into contact with the vicinity of a central portion of the transfer mask main body from a side opposite to the support.