JPH0620916A - Projection exposure method and projection exposure apparatus - Google Patents

Abstract

(57) [Abstract] [Purpose] A single-layer structure of one of the phase shifter film and the light shielding film is used without using a photomask having a two-layer structure using both the phase shifter film and the light shielding film. Two separate photomasks with only the pattern are used so that an effect similar to the phase shift method can be achieved. A light from a light source 101 is divided into a first light P and a second light Q by a half mirror 102, and a phase of a second light Q is inverted by 180 ° by a λ / 2 plate 103. The first light P and the second light Q are transmitted to the first photomask 106 and the second photomask 108, respectively, and the transmitted first light P and the second light Q are transmitted to the half mirror 104.
Synthesize by. The pattern of the first photomask 106 and the pattern of the second photomask 108 are combined, and this combined pattern is projected onto the wafer 110 by the reduction projection lens 105.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection exposure method and apparatus, and more particularly to projection exposure for projecting and exposing a photomask pattern on a film of a photosensitive material on a substrate such as a wafer in a semiconductor device manufacturing process. A method and apparatus.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 13, a projection exposure apparatus used in a semiconductor device manufacturing process has a photomask arranged at a focus image forming position on an optical axis by light from a light source 51, for example. 52 is illuminated, and the illuminated pattern of the photomask 52 is projected onto the photoresist on the wafer 54 (or various thin films already formed on the wafer 54) by the projection lens 53 to be exposed. .

As shown in FIG. 14A, the photomask 52 has a film 522 of a light-shielding material such as a chromium film on the surface of a glass substrate 521 made of quartz glass or the like.
Pattern is formed. When such a photomask 52 is used, the light transmitted through each light-transmitting portion 523 without the light-shielding film 522 has a resolution limit of the projection lens 53 on the wafer 54, as shown in FIG. Due to the restriction, it becomes wider than the mask pattern.
Then, since the respective transmitted lights have the same phase, an interaction that strengthens each other works, and the light intensity distribution on the wafer 54 is such that the patterns are adjacent to each other, as shown in FIG. The two parts cannot be separated. In the case of reduction projection, the pattern of the photomask 52 is reduced and projected on the wafer 54. However, when converted to the dimensions on the wafer 54, the widths of the light shielding film 522 and the light transmitting portion 523 are usually 0.3 to 0. It is 5 μm or more.

Therefore, in recent years, without changing the projection exposure apparatus,
The phase shift method, which can improve the resolution by changing only the photomask, is drawing attention. The phase shift method is described in, for example, the document (24th VLSI FORUM
Forefront of Lithography, "Current State of Phase Shift Lithography" Matsushita Electronics, Kyoto Research Laboratory, Tosho Yoshihiro (1991)
13-25). As shown in FIG. 15A, in the case of a typical Levenson type, the phase shift mask 55 used in this phase shift method has a pattern of a light shielding film 552 on the surface of a glass substrate 551 made of quartz glass or the like. The phase shifter film 554 made of a transparent thin film is formed on the adjacent one of the respective light transmitting portions 553 without the light shielding film 552. When such a phase shift mask 55 is used, as shown in FIG. 15B, the light transmitted through the respective light transmitting portions 553 having the phase shifter film 554 does not have the adjacent phase shifter film 554. The phase is inverted with respect to the light transmitted through the light transmitting portion 553. For this reason, the transmitted lights have an interaction that weakens each other, and the light intensity at the boundary between two adjacent parts of the pattern on the wafer 54 becomes zero, as shown in FIG. , Each pattern part is separated. As described above, according to the phase shift method using the phase shift mask 55, by reversing the phase of the transmitted light, it is possible to resolve an extremely fine pattern that cannot be resolved by the photomask 52.

[0005]

However, since the phase shift mask 55 having a two-layer structure having the light shielding film 552 and the phase shifter film 554 requires extremely precise film thickness control and the like, the light shielding film is required. Compared to the single-layer photomask 52 having only 522, it was very difficult to manufacture and the manufacturing cost was extremely high. Furthermore, the phase shift mask 5
In the case of No. 5, especially if the phase shifter film 554 has a defect, even a defect having an extremely small size is transferred as a pattern. Therefore, the inspection and modification of the phase shift mask 55 are more important, but this inspection and modification have been extremely difficult. Therefore, the phase shift method using the phase shift mask 55 has a problem that it is difficult to apply it to actual semiconductor device manufacturing because of a great increase in cost and various difficulties.

Therefore, an object of the present invention is to use one layer of the phase shifter film and one of the light shielding films without using a photomask having a two layer structure using both the phase shifter film and the light shielding film. It is an object of the present invention to provide a projection exposure method and a projection exposure apparatus which can achieve the same effect as the phase shift method by using two separate photomasks having only the pattern of the structure.

[0007]

In order to achieve the above object, the projection exposure method according to the present invention uses a pattern having a single-layer structure of one of a phase shifter film and a light-shielding film with light having a coherent component. Projecting the respective patterns of the first and second individual photomask elements having: onto a substrate arranged at a predetermined position so that an optical composite pattern of both patterns is formed on the substrate;
A first portion of the light that projects the pattern of the first photomask element onto the substrate and a second portion of the light that projects the pattern of the second photomask element onto the substrate are predetermined. Controlling the phase of at least one of the first light portion and the second light portion so as to have a phase difference.

Further, the projection exposure apparatus according to the present invention includes a light source for generating light having a coherent component and first and second patterns each having a one-layer structure of one of the phase shifter film and the light shielding film. 2 individual photomask elements, means for mounting and positioning the substrate at a predetermined position, and light from the light source for forming the pattern of the first photomask element and the pattern of the second photomask element. Optical means for projecting a composite pattern of both patterns onto the substrate so as to be formed on the substrate; a first portion of the light for projecting the pattern of the first photomask element onto the substrate; At least one of the first light portion and the second light portion has a predetermined phase difference with the second portion of the light that projects the pattern of the second photomask element onto the substrate. It is intended to and a phase control means for controlling the square of the phase.

An embodiment of the projection exposure method according to the present invention is
Focusing an image of the first pattern formed on the first photomask element at a first predetermined position with light having a coherent component; and a second photomask arranged at the predetermined position. Projecting and exposing an optical composite pattern of the second pattern formed on the element and the first pattern of the first photomask element onto the substrate arranged at the second predetermined position with the light And one of the first pattern and the second pattern is formed of a light-shielding film, and the other pattern corresponds to at least one selected portion of the one pattern. It is formed by.

Further, the embodiment of the projection exposure apparatus according to the present invention is such that a light source for generating light having a coherent component, a first photomask element having a predetermined first pattern formed thereon, and a predetermined second pattern. With the photomask means including the second photomask element having the pattern formed therein, the means for holding the substrate in a predetermined position, and the light generated from the light source, the image of the first pattern is formed into the second image. An image is formed on a photomask, and the optically combined pattern of the imaged first pattern of the first photomask element and the second pattern of the second photomask element is projected on the substrate. And an optical means for exposing, wherein one of the first pattern and the second pattern is formed of a light-shielding film, and the other pattern is selected from at least one of the one pattern. It corresponds to the portion, in which are formed by the phase shift film.

Another embodiment of the projection exposure method according to the present invention is to divide light from a light source containing coherent light into a first light and a second light passing through two different optical paths; Controlling the phase of at least one of the first light and the second light so that the first light and the second light have a predetermined phase difference, and a first pattern that forms a predetermined pattern when combined. In a photomask device having a first region and a second region having a partial pattern and a second partial pattern, respectively, the first light and the second region are provided in the first region and the second region. Passing light, and combining the first light having passed through the first region and the second light having passed through the second region to generate combined light having the predetermined pattern. , The combined light having the predetermined pattern on the substrate In which a step of exposing by projecting a film of photosensitive material.

Another embodiment of the projection exposure apparatus according to the present invention splits light from a light source containing light having a coherent component into a first light and a second light passing through two different optical paths. When combined with the splitting means and the phase control means for controlling the phase of at least one of the first light and the second light so that the first light and the second light have a predetermined phase difference. A first region and a second region in which a first partial pattern and a second partial pattern forming a predetermined pattern are formed, respectively, and the first light passes through the first region and Photomask means arranged so that the second light passes through the second region, and the first light that has passed through the first region and the second light that has passed through the second region are combined. And combining means for generating combined light having the predetermined pattern, Those comprising an optical means for the combined light is projected on the film of the photosensitive material on the substrate exposed with a predetermined pattern.

[0013]

In the embodiment of the present invention, the first pattern of the first photomask element is imaged on the second photomask element, and the first pattern and the second pattern of the second photomask element are formed. The composite pattern with the pattern is projected onto the substrate to expose the substrate. Moreover, the first pattern and the second
One of the patterns is formed by a single layer structure of the light shielding film, and the other pattern is formed by a single layer structure of the phase shifter film corresponding to the selected portion of the one pattern, and thus the first pattern The phase of the light for projecting the selected portion of the above onto the substrate is controlled by the phase shifter film of the second pattern formed on the other photomask. It can be realized without using a photomask having a two-layer structure of the film.

According to another embodiment of the present invention, the light having a coherent component from the light source is split into the first light and the second light by the splitting means, and the first light is split by the phase control means. A phase difference is provided between the light and the second light. Since the first light and the second light are passed through the first photomask element and the second photomask element, respectively, the photomask element transmitting the phase-controlled light functions as a phase shift mask. Then, the first photomask element passing through the first photomask element and the second photomask element
Of the first photomask element and the pattern of the second photomask element are combined by combining the second light and the second light by the combining means, and the combined pattern is projected and exposed on the substrate by the optical means. To be done. Therefore,
Phase shift can be realized by using two photomask elements having only the pattern of the light shielding film.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a reduction projection exposure method and a reduction projection exposure apparatus for wafer exposure will be described with reference to the accompanying drawings.

First, a first embodiment of the present invention will be described.
As shown in FIG. 1, the apparatus according to the present embodiment includes a light source 1 including, for example, an ultra-high pressure Hg lamp (i-line) that emits partially coherent light, and an illumination optical system including an elliptical focusing mirror 2 and a condenser lens 3. A unit-magnification projection lens 4 forming an intermediate projection optical system and a reduction projection lens 5 forming an objective projection optical system are provided. Then, the first photomask 6
Is mounted between the condenser lens 3 and the unit size projection lens 4, and a mask mount 9 holding the second photomask 8 is located between the unit size projection lens 4 and the reduction projection lens 5. It is arranged. In addition, the wafer chuck 11 that holds the wafer 10 is mounted on the XY stage 12.
It is supported above and arranged below the reduction projection lens 5. The mask mounts 7 and 9 are configured so that movement adjustment in the X, Y, and Z directions, and further rotation and tilt adjustment in the XY plane are possible. As a result, the first photomask 6 and the second photomask 8 are accurately arranged at different focus image forming positions on the optical axis of the unit magnification projection lens 4.

FIGS. 2 and 3 show a first photomask 6 and a second photomask 8 used when an example of a Levenson type, which is a typical phase shift method, is realized by the method and apparatus of this embodiment. Is shown. As shown in FIGS. 2A and 2B, the first photomask 6 has a pattern of a film 62 of a light-shielding material such as a chrome film formed on the surface of a glass substrate 61 made of quartz glass or the like. is there. Also,
As shown in FIGS. 3A and 3B, the second photomask 8
Is a glass substrate 81 made of quartz glass or the like on which a pattern of a phase shifter film 82 made of a transparent thin film is formed. The first photomask 6 and the second photomask 8 for reduction projection exposure as in this embodiment have an enlarged pattern, and are usually called enlarged masks or reticles.

Then, as shown in FIG. 4, every other light-transmitting portion 63 of the first photomask 6 without the light-shielding film 62, a portion of the phase shifter film 82 of the second photomask 8 is formed. These first photomasks 6 are arranged so as to optically overlap with each other.
And the second photomask 8 is arranged.

According to the apparatus of the present embodiment configured as described above, in FIG. 1, the light having the partially coherent component from the light source 1 is passed through the elliptical focusing mirror 2 and the condenser lens 3 to make the first The photomask 6 is uniformly illuminated, and the pattern of the first photomask 6 is imaged at the position of the second photomask 8 by the unit-magnification projection lens 4. As a result, the pattern of the first photomask 6 and the pattern of the second photomask 8 are combined, and the combined pattern is formed by the reduction projection lens 5 on the wafer 10.
(Or various thin films already formed on the wafer 10) are reduced and projected onto the photoresist. The reduction projection is repeated while the wafer 10 is sequentially moved in the X and Y directions by the XY stage 12, and the entire surface of the wafer 10 is exposed by this step and repeat.

In the projection exposure as described above, FIG.
As shown in (a), when only the first photomask 6 is projected, the lights transmitted through the respective light transmitting portions 63 are distributed on the wafer in the same phase. However, by superimposing and projecting the first photomask 6 and the second photomask 8, the pattern of the first photomask 6 and the pattern of the second photomask 8 are combined, so that FIG. As shown in b), of the light transmitted through each light transmitting portion 63 of the first photomask 6, the light transmitted through each phase shifter film 82 of the second photomask 8 is converted into the phase shifter film 82. The phase is inverted for light that does not pass through. Then, the light intensity on the wafer 10 at this time is, as shown in FIG.
The light intensity at the boundary between two adjacent parts of the pattern becomes zero,
Each pattern part is separated. Therefore, from FIGS. 5B and 5C, using the first photomask 6 having the one-layer structure and the second photomask 8 having the one-layer structure, the phase of the two-layer structure shown in FIG. It can be seen that a phase shift method equivalent to that using the shift mask 55 is realized.

Further, in this embodiment, the mask having the light-shielding film was used as the first photomask and the mask having the phase shifter film was used as the second photomask, but these masks may be used in reverse. Good. Further, in this embodiment, the i-line Hg lamp is used as the light source, but it is clear that the same effect can be obtained by using the g-line Hg lamp, the excimer laser light source, or the like.

As described above, according to the first embodiment, the pattern of the first photomask and the pattern of the second photomask are combined and projected to form a one-layer structure having a light shielding film. The same effect as when using a conventional two-layer structure phase shift mask having a light-shielding film and a phase shifter film is realized by using the photomask and the one-layer structure phase shift mask having a phase shifter film. can do. Therefore, instead of the conventional complicated phase shift mask having a two-layer structure, which is very difficult to manufacture and extremely difficult to inspect and repair, a single-layer structure photomask (for example, a chrome mask) and 1 which can be manufactured by a single-layer resist process are used. Since the phase shift mask having a layered structure can be used, it is possible to significantly reduce the cost in the phase shift method and effectively apply it to actual semiconductor device manufacturing and the like.

Next, a second embodiment of the present invention will be described.
As shown in FIG. 6, the apparatus of this embodiment includes a light source 101, for example, an excimer laser light source that generates light having a coherent component, and a first light P that passes light from the light source 101 through different optical paths. And a half mirror (beam splitter) 102 that splits the second light Q into two.
Of the first light so that the light P and the second light Q have a predetermined phase difference.
Λ / 2 plate 103 for controlling the phase of at least one of the light P and the second light Q (second light Q in this embodiment).
And a half mirror (beam splitter) 104 that combines the first light P and the second light Q, and a reduction projection lens 105 that constitutes an objective projection optical system. Note that λ
The / 2 plate 103 is a device capable of controlling the optical path length of light, and the phase of the light passing through this λ / 2 plate 103 is 18
It is made of glass whose refraction and length are determined so as to be inverted by 0 °. Further, 113 and 114 are total reflection mirrors. Then, a mask mount 107 holding the first photomask 106 is arranged on the optical path of the first light P between the half mirror 102 and the total reflection mirror 113,
Mask mount 1 for holding the second photomask 108
09 is arranged on the optical path of the second light Q between the total reflection mirror 114 and the half mirror 104. A wafer chuck 111 that holds the wafer 110 is supported on the XY stage 112 and arranged below the reduction projection lens 105. The mask mounts 107 and 109
Is configured such that movements in the X, Y and Z directions, and further rotation and tilt movement in the XY plane can be adjusted independently. As a result, the first photomask 106 and the second photomask 108 are accurately arranged on the optical paths of the first light P and the second light Q.

FIGS. 7 and 8 show a first photomask 106 used for realizing the same effect as the Levenson type, which is a typical phase shift method, by the method and apparatus of this embodiment.
And a second photomask 108. Figure 7
As shown in (a) and (b), the first photomask 106 is formed.
Is a pattern of a film 162 of a light-shielding material such as a chromium film formed on the surface of a glass substrate 161 made of quartz glass or the like. Further, as shown in FIGS. 8A and 8B, the second photomask 108 also has a pattern of the light shielding film 182 formed on the surface of the glass substrate 181 made of quartz glass or the like. The first photomask 106 and the second photomask 108 for reduction projection exposure as in this embodiment have an enlarged pattern,
Usually referred to as a magnifying mask or reticle.

When the pattern of the first photomask 106 and the pattern of the second photomask 108 are combined,
It is formed so as to give a predetermined pattern to be exposed on the wafer 110. That is, as shown in FIG. 9, the light-transmitting portion 1 of the first photomask 106 without the light-shielding film 162.
63 and the light-transmitting portion 183 of the second photomask 108 without the light-shielding film 182 are set to be optically staggered, and the respective patterns have the first light P and the second light Q.
The pattern appears alternately when projected onto the wafer 110, and the pattern obtained by combining the two coincides with the pattern to be projected and exposed on the wafer 110.

According to the apparatus of the present embodiment configured as described above, in FIG. 6, the light having the coherent component from the light source 101 is converted into the first light P and the second light Q by the half mirror 102. Will be divided. The first light P passes through the first photomask 106, is reflected by the total reflection mirror 113, and reaches the half mirror 104. In addition, the second light Q passes through the λ / 2 plate 103, has its phase inverted by 180 °, is reflected by the total reflection mirror 114, passes through the second photomask 108, and reaches the half mirror 104. . Then, the first light P and the second light Q are combined by the half mirror 104, whereby the pattern of the first photomask 106 and the pattern of the second photomask 108 are combined, and this combined pattern is obtained. The reduction projection lens 105 performs reduction projection on the photoresist on the wafer 110 (or various thin films already formed on the wafer 110). The reduction projection is repeated while the wafer 110 is sequentially moved in the X and Y directions by the XY stage 112, and the entire surface of the wafer 110 is exposed by this step and repeat.

In the projection exposure as described above, FIG.
As shown in (a), the amplitude of the first light P transmitted through the first photomask 106 is such that the light transmitted through each light transmitting portion 163 spreads in the same phase. Further, as shown in FIG. 10B, the amplitude of the second light Q transmitted through the second photomask 108 also spreads in the same phase as the light transmitted through the respective light transmitting portions 183. The phase is inverted with respect to the first light P. That is, by the second light Q whose phase is inverted, the second photomask 108 functions as a phase shift mask having a phase shifter film while being a mask having only the pattern of the light shielding film 182. Then, the pattern of the first photomask 106 formed by the first light P and the pattern of the second photomask 108 formed by the second light Q are combined, so that the wafer 110 at this time is combined.
As for the above-mentioned light intensity, as shown in FIG. 10C, the light intensity at the boundary between the adjacent portions of the pattern becomes zero, and the respective pattern portions are separated. Therefore, from FIG. 10A, FIG. 10B, and FIG. 10C, the first pattern having only the pattern of the light shielding film 162 is formed.
15 and the second photomask 108 having only the pattern of the light shielding film 182 is used.
Of the light-shielding film 552 and the phase shifter film 55 shown in FIG.
It can be seen that the same effect as when the phase shift mask 55 having the pattern of 4 is used.

Further, although the phase of only one light is controlled in this embodiment, the phases of both lights may be controlled. Further, in the present embodiment, the photomask is transmitted after controlling the phase of light, but the phase may be controlled after transmitting the photomask.

As described above, according to the second embodiment, the first light and the second light whose phase is controlled are divided into two.
Light is respectively transmitted to the first photomask and the second photomask, and the pattern of the first photomask and the pattern of the second photomask are combined and projected, so that only the pattern of the light-shielding film is formed. By using the two photomasks included therein, it is possible to realize the phase shift method that achieves the same effect as the phase shift method using the conventional phase shift mask having the phase shifter film. Therefore, use a relatively inexpensive and proven photomask (for example, a chrome mask) instead of a conventional phase shift mask that is very difficult to manufacture due to high-precision film thickness control and is extremely difficult to inspect and correct. Therefore, it is possible to significantly reduce the cost of the phase shift method and effectively apply it to actual semiconductor device manufacturing and the like.

Next, a third embodiment of the present invention will be described.
In FIG. 11, the same elements as those in FIG. 6 are indicated by the same reference numerals. In the third embodiment, instead of the first and second photomasks 106 and 108 and the mask mounts 107 and 109 holding these in the second embodiment, a first region (first photomask element) is used. 208 and the second area (second
Photomask element) and one photomount 206 that holds the photomask 206 and one mask mount 20 that holds the photomask 206.
It is the same as the second embodiment except that 7 is provided. The mask mount 207 is configured such that movement in the X, Y, and Z directions, rotational movement in the XY plane, and tilt angle can be adjusted independently. As a result, the photomask 2
The first region 208 and the second region 209 of 06 are accurately arranged in the optical paths of the first light P and the second light Q.

As shown in FIGS. 12A and 12B, the photomask 206 has a first pattern in which a film 281 of a light shielding material such as a chromium film is formed on the surface of a glass substrate 261 such as quartz glass. A region 208 and a second region 209 having a pattern of the light shielding film 291 are provided. It should be noted that 282 and 292 are translucent parts similar to those described above. The positional relationship between the patterns of the first region 208 and the second region 209 is the same as that of the first photomask 10 in the second embodiment.
6 pattern of the light shielding film 162 and the second photomask 10
8 is the same as the positional relationship of the pattern of the light shielding film 182.
Therefore, in the third embodiment, as in the second embodiment, the combined pattern of the pattern of the first region 208 and the pattern of the second region 209 is projected and exposed on the wafer 110 to form an adjacent pattern. The parts are separated in the same way as described with reference to FIGS. 9 and 10.

The embodiments of the present invention have been described above.
The present invention is not limited to the above embodiments, and various effective modifications and applications are possible based on the technical idea of the present invention. For example, according to the method and apparatus of the present invention, it is obvious that other phase shift methods such as edge enhancement type and transmission type other than the Levenson type of the embodiment can be realized. The present invention can be applied to not only the reduction projection exposure method and apparatus for wafer exposure but also the projection exposure method and apparatus for projecting and exposing various photomask patterns on various substrates.

[0033]

As described above, according to the present invention,
Without using a photomask having a two-layer structure using both the phase shifter film and the light-shielding film, two separate photo patterns having only a one-layer structure pattern of one of the phase shifter film and the light-shielding film are used. A mask can be used to achieve the same effect as the phase shift method. Therefore, instead of the conventional complicated phase shift mask having a two-layer structure, which is extremely difficult to manufacture due to high-precision film thickness control, etc. and extremely difficult to inspect and repair, it can be manufactured by a single-layer resist process at a relatively low cost. Since it is possible to use a photomask having a certain one-layer structure, it is possible to significantly reduce the cost in the phase shift method and effectively apply it to actual semiconductor device manufacturing and the like.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing the configuration of a projection exposure apparatus according to a first embodiment of the present invention.

2A and 2B show a first photomask element used in the first embodiment, wherein FIG. 2A is a plan view and FIG. 2B is a sectional view.

3A and 3B show a second photomask element used in the first embodiment, FIG. 3A is a plan view and FIG. 3B is a sectional view.

FIG. 4 is a diagram showing an optical positional relationship between a first pattern of a first photomask element and a second pattern of a second photomask element.

5 (a), (b) and (c) respectively show a distribution of the intensity of light passing through only the pattern of the first photomask element, a distribution of the intensity of light passing through the second photomask element, FIG. 3 is a diagram showing an intensity distribution of their combined light.

FIG. 6 is a schematic perspective view showing the configuration of a projection exposure apparatus according to the second embodiment of the present invention.

7A and 7B show a first photomask element used in a second embodiment, FIG. 7A is a plan view, and FIG. 7B is a sectional view.

FIG. 8 shows a second photomask element used in the second embodiment, (a) is a plan view and (b) is a sectional view.

FIG. 9 is a diagram showing an optical positional relationship between a first pattern of a first photomask element and a second pattern of a second photomask element.

10 (a), (b) and (c) are respectively the first
FIG. 3 is a diagram showing a distribution of intensity of light passing through a pattern of the photomask element, a distribution of intensity of light passing through a second photomask element, and an intensity distribution of their combined light.

FIG. 11 is a schematic perspective view showing the configuration of a projection exposure apparatus according to the third embodiment of the present invention.

12A and 12B show a photomask apparatus used in a third embodiment, FIG. 12A is a plan view and FIG. 12B is a sectional view.

FIG. 13 is a schematic diagram showing a configuration of a conventional projection exposure apparatus.

14A, 14B, and 14C are cross-sectional views of a conventional photomask, an intensity distribution of light passing through the photomask, and an intensity distribution of combined light projected on a substrate, respectively. Is.

15 (a), (b) and (c) are a cross-sectional view of a conventional phase shift mask, an intensity distribution of light passing through the phase shift mask and an intensity distribution of synthetic light projected on a substrate, respectively. FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 light source 4 1x projection lens 5 reduction projection lens 6 1st photomask 8 2nd photomask 62 light-shielding film 63 translucent part 82 phase shifter film 7, 9 mask mount 10 wafer 101 light source 102 half mirror (splitting means) 103 λ / 2 Plate (Phase Controlling Means) 104 Half Mirror (Combining Means) 105 Reduction Projecting Lens 106 First Photomask 108 Second Photomask 162, 182 Light-shielding Films 163, 183 Light Transmitting Section 107, 109 Mask Mount 110 Wafer 206 Photomask 208 First region 209 Second region 281, 291 Light-shielding film 282, 292 Light transmitting part 207 Mask mount

Claims (12)

[Claims] 1. A pattern having a single-layer structure of one of a phase shifter film and a light-shielding film having a pattern of a single layer is defined by light having a coherent component. Projecting an optically synthesized pattern of both patterns on a substrate arranged in a position so as to be formed on the substrate; and a step of projecting the pattern of the first photomask element onto the substrate. The first light portion and the second light portion are arranged so that the first portion and the second portion of the light for projecting the pattern of the second photomask element onto the substrate have a predetermined phase difference. Controlling the phase of at least one of the parts. 2. A step of focusing an image of a first pattern formed on a first photomask element at a first predetermined position with light having a coherent component; and the step of arranging at the predetermined position. An optical composite pattern of the second pattern formed on the second photomask element and the first pattern of the first photomask element is placed on the substrate arranged at the second predetermined position with the light. Projecting and exposing the first pattern and the second pattern with a light-shielding film, and the other pattern corresponds to at least one selected portion of the one pattern. Then
A projection exposure method formed by a phase shifter film. 3. A light source for generating light having a coherent component, and first and second individual photomask elements each having a pattern of a single-layer structure of either one of a phase shifter film and a light shielding film. A means for mounting and positioning the substrate at a predetermined position, and using the light from the light source, the pattern of the first photomask element and the pattern of the second photomask element are combined on the substrate, and both patterns are combined. Optical means for projecting a pattern so that it is formed on the substrate, a first portion of the light for projecting the pattern of the first photomask element on the substrate, and a pattern of the second photomask element A phase controller for controlling the phase of at least one of the first light portion and the second light portion so that the second portion of the light projecting onto the substrate has a predetermined phase difference. Projection exposure apparatus having a door. 4. A light source for generating light having a coherent component, a first photomask element having a predetermined first pattern formed thereon, and a second photomask having a predetermined second pattern formed thereon. Photomask means including an element, means for holding the substrate in a predetermined position, and light generated from the light source to form an image of the first pattern on the second photomask, Optical means for projecting and exposing an optical composite pattern of the imaged first pattern of the first photomask element and the second pattern of the second photomask element onto the substrate, One of the first pattern and the second pattern is formed of a light-shielding film, and the other pattern corresponds to at least one selected portion of the one pattern,
A projection exposure apparatus formed of a phase shift film. 5. A step of splitting light from a light source including coherent light into a first light and a second light which pass through two different optical paths, and the first light and the second light having predetermined positions. Controlling a phase of at least one of the first light and the second light so as to have a phase difference; and having a first partial pattern and a second partial pattern which form a predetermined pattern when combined. The first of a photomask device having a first region and a second region,
A step of passing the first light and the second light through the area and the second area; a first light that has passed through the first area and a second light that has passed through the second area. Projection exposure including combining light to generate combined light having the predetermined pattern, and projecting the combined light having the predetermined pattern onto a film of a photosensitive material on a substrate to expose the film. Method. 6. The phase of one of the first light and the second light is controlled so that the phase difference between the first light and the second light is 180 °. The projection exposure method according to claim 5. 7. The projection exposure method according to claim 5, wherein the step of controlling the phase is applied to one of the first light and the second light. 8. The step of controlling the phase prior to one of the first light and the second light passing through one of the first and second regions associated therewith. The projection exposure method according to claim 7, wherein the projection exposure method is performed. 9. Splitting means for splitting light from a light source containing light having a coherent component into a first light and a second light passing through two different optical paths, and the first light and the second light. Phase control means for controlling the phase of at least one of the first light and the second light so that the light has a predetermined phase difference; and a first partial pattern and a first partial pattern that form a predetermined pattern when combined. First with two partial patterns each formed
And a second region, the photomask means being arranged so that the first light passes through the first region and the second light passes through the second region, Combining the first light that has passed through the first region and the second light that has passed through the second region to generate combined light that has the predetermined pattern, and a combining unit that has the predetermined pattern. A projection exposure apparatus comprising: an optical unit that projects the combined light onto a film of a photosensitive material on a substrate to expose the film. 10. The projection exposure apparatus according to claim 9, wherein the predetermined phase difference between the first light and the second light is 180 °. 11. The projection exposure apparatus according to claim 9, wherein the phase control unit controls one phase of the first light and the second light. 12. The photomask means is arranged such that, after one of the first light and the second light is phase-controlled by the phase control means, the photomask means is associated with the first region and the second area. The projection exposure apparatus according to claim 11, wherein the projection exposure apparatus is arranged so as to pass through one of the areas.