JPH1167638A - Method and device for exposure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exposing method and an exposing device, which perform the large-area exposure to a substrate under the state of the conventional exposure region of an X-ray mask and an X-ray irradiation region. SOLUTION: An X-ray source 1 is made to transmit through X-ray masks 5 and 6, which are mounted on a mask stage 4, and the pattern drawn on the mask is transferred on a wafer 7 mounted on a wafer stage 8. At this time, the position alignment of the X-ray mask 5 mounted on the mask stage 4 and the wafer 7 facing the x-ray mask is performed. Thereafter, the pattern drawn on the X-ray mask 5 is transferred to the wafer 7. Then, the pattern drawn on the X-ray mask 6 is transferred to the wafer 7 by the same operation. Thus, the exposure of the large area can be performed by only switching the mask, without enlarging the magnitude of the main body of the mask.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an exposure apparatus and an exposure method used in a lithography process for producing an LSI.

[0002]

2. Description of the Related Art In recent years, as high-density and high-speed large-scale integrated circuits (LSIs) have been required to miniaturize elements, the wavelength of light used in a photolithography process in the manufacturing process is short. Since a finer element can be formed, X-ray exposure using a soft X-ray having a wavelength of about 1 nm (hereinafter simply referred to as X-ray) as a light source is expected as a next-generation exposure method. In this exposure using X-rays, generally, exposure at the same magnification is performed.

A conventional X-ray exposure method and exposure apparatus will be described below with reference to FIG.

[0004] S emitted from an SR ring (X-ray source) 1
The R light (X-ray) 2 is guided into the X-ray exposure device 12 with the X-ray irradiation area enlarged by scanning by the X-ray mirror 3.
On the other hand, one X-ray mask 5 is mounted on the mask stage 4, and the wafer 7 mounted on the wafer stage 8 and the X-ray mask 5 are arranged in a close gap of 10 to 50 μm. Then, the pattern image of the X-ray mask 5 is transferred onto the wafer 7 by the step-and-repeat method of the wafer stage 8 by the guided SR light (X-ray). The position of the wafer stage is detected through a laser length measuring device 10 and is controlled by a control system 10.

As described above, since the X-ray exposure can be performed without using a lens system, the X-ray exposure is not limited by the size of the imaging system lens as in the case of light exposure, so that the X-ray exposure has a large area. It is said that it is suitable for light exposure.

Specifically, in order to perform a large-area exposure in the X-ray exposure, the exposure area of the X-ray mask is enlarged, and the entire X-ray exposure area is irradiated by X-ray irradiation by mirror scanning or the like. Is realized by:

The X-ray lithography technology and the exposure apparatus are described in, for example, “Monthly SemiconductorWorld Magazine”, July 1990, Press Journal, p.
December, 994 separate volume super LSI manufacturing test equipment guidebook 1996 edition "(Industry Research Institute Co., Ltd.) p52," BR
EAK THROUGH, October 1994 issue (Realize) feature page.

[0008]

However, in the conventional method for enlarging the exposure area of an X-ray mask for performing a large-area exposure in the X-ray exposure, the size of the membrane area of the X-ray mask is increased. We have to go. The membrane of the X-ray mask is formed of a SiN or SiC thin film having a thickness of about 2 μm.
It is easily anticipated that it will be difficult to maintain membrane strength, stress control, and pattern position accuracy.

Further, when the area is increased by enlarging an X-ray irradiation area by mirror scanning, as shown in FIG. 5, a "run-out error" (also referred to as a half-blur) is generally used.
This causes an increase in the transfer position deviation error referred to as “transfer position deviation error”. This run-out error is caused by the fact that X-rays are not incident in parallel, and a problem that occurs as long as the pattern drawn on the mask is transferred by reflecting the X-rays with a mirror as shown in FIG. Is a point. If the X-rays are not incident in parallel, the pattern is actually transferred onto the wafer larger than the mask. Then, as shown in FIG. 5, the larger the area of the mask, the larger the run-out error.

[0010] The "run-out error" is a problem that can always exist in an exposure method in which a proximity gap exists between a mask and a wafer, in addition to the X-ray exposure.

[0011] Further, even in the present general light exposure method other than the X-ray lithography, the mask becomes larger and larger for the large-area exposure, and the exposure optical system also becomes larger accordingly. New breakthroughs are needed in terms of utilization efficiency and lens materials.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide an exposure method and an exposure apparatus for performing a large-area exposure on a substrate while keeping the conventional X-ray mask exposure area and X-ray irradiation area. I do.

[0013]

According to the present invention, there is provided an exposure method for transferring a pattern drawn on a first substrate onto a second substrate.
A mark detection step of detecting at least two pattern regions on the first substrate, the mark providing position information of the second substrate; and a first substrate based on a result obtained by the mark detection step. A step of calculating coordinates at which the second substrate is to be stopped with respect to the first pattern area, and a step of sequentially positioning the second substrate at a position determined based on the calculation result And an exposure step of transferring a first pattern area on the first substrate onto a second substrate; and exposing at least two or more pattern areas on the first substrate to one imaging optical system. A first substrate positioning step of selectively moving and positioning the first pattern area, and an exposure step of transferring the whole or a part of the selected pattern area onto the second substrate. Further, the exposure images of the plurality of pattern regions on the first substrate are connected together adjacently or at least partially overlapped on the second substrate to form the second image.
A desired pattern is formed on the substrate.

In order to achieve the above object, an exposure method according to the present invention is characterized in that an X-ray, a beam in the vacuum ultraviolet region or an electron beam is drawn on a mask by passing through two or more masks mounted on a mask stage. When transferring the pattern to the wafer mounted on the wafer stage, the first mask mounted on the mask stage is aligned with the X-ray, beam in the vacuum ultraviolet region, or the projection region of the electron beam, and the first mask is aligned. After aligning the wafer with respect to the mask, a step of transferring the pattern drawn on the first mask to the wafer, and a second mask mounted on a mask stage and X-rays, a beam in a vacuum ultraviolet region or Transferring the pattern drawn on the second mask to the wafer after performing the alignment of the projection area of the electron beam and the positioning of the wafer with respect to the second mask; and You have me.

When transferring a pattern drawn on the mask to a wafer mounted on a wafer stage by transmitting an X-ray, a beam or an electron beam in the vacuum ultraviolet region through the mask mounted on the mask stage, Has two or more pattern regions formed apart from each other, and aligns a first pattern region formed on a mask with a projection region of a beam or an electron beam of an X-ray, a vacuum ultraviolet region, and a first region. After aligning the wafer with respect to the pattern area, the first
Transferring the pattern drawn on the pattern area to the wafer, aligning the second pattern area mounted on the mask stage with the beam or electron beam projection area in the X-ray, vacuum ultraviolet region, and the second step. And then transferring the pattern drawn in the second pattern area to the wafer after the wafer is aligned with the pattern area.

According to this configuration, it is possible to expose a large-area wafer without increasing the area of the mask.

Further, the exposure apparatus of the present invention mounts a beam or electron beam source in the X-ray or vacuum ultraviolet region, a mask stage on which two or more masks are mounted, and a wafer on which a pattern drawn on the mask is transferred. A configuration having a wafer stage to be mounted, a unit for positioning two or more masks mounted on the mask stage and an X-ray projection area, and a unit for positioning the wafer with respect to the two or more masks Or a beam or electron beam source in the X-ray, vacuum ultraviolet region,
A mask stage for mounting a mask having two or more pattern regions formed apart from each other, and a wafer stage for mounting a wafer for transferring a pattern drawn on the mask,
Means for aligning two or more pattern regions formed on a mask stage spaced apart from each other and an X-ray projection region, and a wafer for two or more pattern regions formed separately on a mask stage And a means for performing position alignment.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An exposure apparatus and an exposure method according to an embodiment of the present invention will be described below with reference to the drawings. In the following embodiments, the description will be made basically with exposure at the same magnification.

(Embodiment 1) FIG. 1 shows a configuration diagram of an exposure apparatus according to Embodiment 1 of the present invention.

In FIG. 1, 1 is an SR ring as an X-ray source, 2 is an SR light (X-ray) emitted from the SR ring 1,
Reference numeral 3 denotes an X-ray mirror for enlarging an X-ray irradiation area when guided to an X-ray exposure apparatus, and reference numeral 4 denotes at least two or more (two in this embodiment) X-ray masks are mounted. Mask stages, 5 and 6 are X-ray masks, 7 is a silicon wafer, 8 is a wafer stage, 9 and 10 are laser measuring devices for detecting the positions of the mask stage 4 and the wafer stage 8, respectively, and 11 is a mask stage 4 And a control system for controlling the driving of the wafer stage 8.

Next, an exposure method using the exposure apparatus having the above configuration will be described below.

First, an X-ray mask 5 as a first mask
Then, an X-ray mask 6 as a second mask is mounted on a predetermined position of the mask stage 4 by performing alignment. The pattern area of each of the X-ray mask 5 and the X-ray mask 6 is, for example, 25 mm vertically and 50 mm horizontally. Next, positioning is performed by the laser length measuring device 9 and the control system 11 so that the pattern position of the X mask 5 falls within the X-ray projection area. Next, the wafer 7 is mounted on the wafer stage 8, and then alignment marks provided on the X-ray mask 5 and alignment marks provided on the wafer 7 are detected by an alignment optical system.
The wafer stage 8 is driven in accordance with the result calculated by the control system 11, and the X-ray mask 5 and the wafer 7 are positioned. The proximity gap between the X-ray mask 5 and the wafer 7 is 20 μm. SR ring 1
SR light 2 radiated from the X-ray mirror 3 is condensed by a converging mirror (not shown) provided in a vacuum, is then expanded in the vertical direction by an X-ray mirror 3, passes through an X-ray mask 5, The pattern of the X-ray mask 5 is transferred onto the wafer 7.

Next, positioning is performed by the laser length measuring device 9 and the control system 11 so that the pattern area of the X-ray mask 6 falls within the X-ray projection area, and the mask stage is driven.
Next, the wafer stage 8 is positioned by the laser length measuring device 10 and the control system 11 so that the next exposure area of the wafer 7 is positioned so as to be adjacently connected or at least partially overlapped. Then, the wafer stage 8 is driven so as to enter the X-ray projection area. Then, an alignment mark provided on the X-ray mask 6 and an alignment mark provided on the wafer 7 are detected by an alignment optical system.
The wafer stage 8 is driven in accordance with the result calculated by the control system 10 and the control system 11, and the X-ray mask 6 and the wafer 7 are positioned. S radiated from SR ring 1
The R light 2 is condensed by a converging mirror provided in a vacuum, and is then expanded in the vertical direction by an X-ray mirror 3 so that the X-ray mask 6
To transfer the pattern of the X-ray mask 6 onto the wafer 7.

As described above, according to the present embodiment, even if the area of the chip becomes large, it is not necessary to enlarge the mask accordingly. Since the pattern can be transferred to the wafer by placing the mask on the top and moving the two masks, the following effects can be obtained.

First, since a mask having the same size as the conventional one is used, a large-area mask which is difficult to manufacture is not required. Second, since the area of the mask itself does not increase, it is possible to prevent the runout error from increasing.

In this embodiment, immediately after the wafer transfer using the X-ray mask 5, the wafer transfer using the X-ray mask 6 is performed to transfer one chip pattern as a whole. Repeated them, and explained the example where multiple chip patterns are formed on the whole wafer,
In the exposure method and the exposure apparatus according to the present invention, the wafer transfer using the X-ray mask 5 is repeated to cover the entire wafer with the X-ray mask 5.
After the above pattern is formed, wafer transfer using the X-ray mask 6 may be repeated to form the pattern of the X-ray mask 6 on the entire wafer, and a plurality of chip patterns may be formed on the entire wafer.

(Embodiment 2) FIG. 2 shows a configuration diagram of an exposure apparatus according to Embodiment 2 of the present invention.

In FIG. 2, 1 is an SR ring as an X-ray source, 2 is an SR light (X-ray) emitted from the SR ring 1,
Reference numeral 3 denotes an X-ray mirror for enlarging an X-ray irradiation area when guided to an X-ray exposure apparatus, 4 denotes a mask stage on which at least two or more X-ray masks are mounted, and 25 denotes a pattern area A.
An X-ray mask having two pattern areas 26 and a pattern area B27, 7 is a silicon wafer, 8 is a wafer stage, 9 and 10 are laser length measuring devices for detecting the positions of the mask stage 4 and the wafer stage 8, respectively. Reference numeral 11 denotes a control system for controlling driving of the mask stage 4 and the wafer stage 8. That is, the present embodiment is different from the above-described first embodiment in that two or more masks are not independently formed and mounted on a mask stage.
The point is that a region which is formed independently on one mask and is actually used as a mask is formed (a pattern region spaced apart from one mask is formed).

Next, an exposure method using an exposure apparatus having the above-described configuration will be described.

First, the X-ray mask 25 is mounted at a predetermined position on the mask stage 4 by performing alignment. At this time, the pattern area of the X-ray mask 25 is as shown in FIG.
For example, as shown in FIG.
Two pattern areas A and B of 0 mm are formed (in the conventional X-ray mask, only one pattern area 31 is formed as shown in FIG. 3A). Next, the laser length measuring device 9 is set so that the pattern area A26 as the first pattern area of the X mask 25 falls in the X-ray projection area.
Positioning is performed by the control system 11. Next, the wafer 7 is mounted on the wafer stage 8, and then an alignment mark provided on the X-ray mask 25 and an alignment mark provided on the wafer 7 are detected by an alignment optical system. The wafer stage 8 is driven according to the result calculated by the system 11, and the X-ray mask 25 and the wafer 7 are positioned. The proximity gap between the X-ray mask 25 and the wafer 7 is 20 μm
It is. The SR light 2 radiated from the SR ring 1 is condensed by a converging mirror (not shown) provided in a vacuum, and then expanded in the vertical direction by an X-ray mirror 3.
5, the pattern in the pattern area A26 of the X-ray mask 25 is transferred onto the wafer 7.

Next, positioning is performed by the laser length measuring device 9 and the control system 11 so that the pattern area B27 as the second pattern area of the X-ray mask 25 falls within the X-ray projection area, and the mask stage is moved. Drive. Next, the wafer 7
So that the next exposure area of
Alternatively, the wafer stage 8 is placed on the laser length measuring device 10 so that the wafer stage 8 is at least partially overlapped.
While positioning by the control system 11, the wafer stage 8 is driven to enter the X-ray projection area. And
The alignment mark provided on the X-ray mask 25 and the alignment mark provided on the wafer 7 are detected by the alignment optical system, and the wafer stage 8 is driven according to the result calculated by the laser length measuring devices 9 and 10 and the control system 11. Then, the X-ray mask 25 and the wafer 7 are positioned. The SR light 2 radiated from the SR ring 1 is condensed by a converging mirror provided in a vacuum, and then expanded vertically by an X-ray mirror 3, transmitted through an X-ray mask 25, and The pattern in the pattern area B27 of the mask 25 is transferred onto the wafer 7.

As described above, according to the present embodiment, even if the area of the chip becomes large, it is not necessary to increase the area of the mask accordingly. Since the pattern can be transferred to the wafer by placing the mask on the top and moving the two masks, the following effects can be obtained.

First, since a mask having the same size as the conventional one is used, a large-area mask which is difficult to manufacture is not required. Second, since the area of the mask itself does not increase, it is possible to prevent the runout error from increasing. Further, according to the present embodiment, although the manufacturing of the mask is slightly inferior to that of the first embodiment, the distance between the two mask regions is determined when the mask is created. The displacement generated at the time of movement can be reduced.

In this embodiment, the pattern area A
Immediately after the wafer transfer using the wafer pattern 26, the wafer transfer using the pattern area B27 is performed to transfer one chip pattern as a whole, and these are repeated to form a plurality of chip patterns on the entire wafer. Although the case has been described as an example, in the exposure method and the exposure apparatus according to the present invention, the wafer transfer using the pattern area A26 is repeated to form a pattern corresponding to the pattern area A on the entire wafer, and then the pattern area B27 is used. A method in which the wafer transfer is repeated to form a pattern corresponding to the pattern region B on the entire wafer and a plurality of chip patterns are formed on the entire wafer may be used.

In the embodiment, an exposure method and an exposure apparatus using X-rays are described as an example. However, in addition to the X-rays, an exposure method and an electron beam using a beam in a vacuum ultraviolet region or an electron beam are used.
Similar effects can be obtained with an exposure apparatus.

[0036]

According to the exposure method and the exposure apparatus of the present invention, a single substrate has a plurality of exposure pattern areas.
Introducing an exposure mask, selectively moving and positioning multiple exposure pattern areas with respect to one imaging optical system, or introducing multiple exposure masks on one mask stage, By selectively moving and positioning the exposure pattern area with respect to one imaging optical system, a large-area circuit pattern having a fine pattern can be accurately and rapidly transferred. Further, error factors such as run-out errors caused by the increase in area can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an exposure apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a schematic view of an exposure apparatus according to Embodiment 2 of the present invention.

FIG. 3 is a schematic view of a mask used in an exposure method according to Embodiment 2 of the present invention.

FIG. 4 is a schematic view of a conventional exposure apparatus.

FIG. 5 is a schematic view showing the vicinity of a mask of a conventional exposure apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 SR ring 2 SR light 3 X-ray mirror 4 Mask stage 5 X-ray mask 6 X-ray mask 7 Wafer 8 Wafer stage 9 Laser length measuring device 10 Laser length measuring device 11 Control system 12 X-ray exposure apparatus 25 X-ray mask 26 pattern Area A 27 Pattern area B 31 Pattern area 51 Run-out error

Claims (4)

[Claims] An X-ray, a beam in a vacuum ultraviolet region or an electron beam is transmitted through two or more masks mounted on a mask stage, and a pattern drawn on the mask is applied to a wafer mounted on a wafer stage. An exposure method for transferring, comprising: a first mask mounted on the mask stage;
Transferring a pattern drawn on the first mask to the wafer after performing alignment of a projection area of a beam or an electron beam in a vacuum ultraviolet region and alignment of the wafer with respect to the first mask. And after aligning the second mask mounted on the mask stage with the X-ray, the beam or electron beam projection area in the vacuum ultraviolet region, and aligning the wafer with the second mask. Transferring a pattern drawn on the second mask to the wafer. 2. An exposure method for transferring a pattern drawn on a mask onto a wafer mounted on a wafer stage by transmitting an X-ray, a beam or an electron beam in a vacuum ultraviolet region through the mask mounted on the mask stage. Wherein the mask has two or more pattern regions formed apart from each other, and a first pattern region formed on the mask and the X-ray,
A step of transferring a pattern drawn in the first pattern area to the wafer after performing alignment of a projection area of a beam or an electron beam in a vacuum ultraviolet region and alignment of the wafer with respect to the first pattern area. And a second pattern region mounted on the mask stage and the X
After the alignment of the projection area of the beam or the electron beam in the vacuum ultraviolet region and the alignment of the wafer with respect to the second pattern area, the pattern drawn in the second pattern area is transferred to the wafer. An exposure method. 3. A beam stage or an electron beam source in an X-ray or vacuum ultraviolet region, a mask stage on which two or more masks are mounted, and
A wafer stage on which a wafer for transferring a pattern drawn on the mask is mounted; a means for aligning two or more masks mounted on the mask stage with the X-ray projection area; Means for aligning the wafer with respect to at least two or more masks. 4. A mask stage on which a mask having two or more pattern regions formed separately from a beam or an electron beam source in an X-ray or vacuum ultraviolet region, and a pattern drawn on the mask are provided. A wafer stage on which a wafer to be transferred is mounted, and a means for aligning two or more pattern regions formed separately from the mask mounted on the mask stage with the X-ray projection region; Means for aligning the wafer with respect to two or more pattern regions formed apart from each other.