JPH07306522A - Phase shift photomask - Google Patents

Abstract

PURPOSE:To provide a phase shift photomask for producing semiconductor integrated circuits, such as LSIs, VLSIs and VVLSIs and is capable of dealing particularly with the case where fine line patterns 5 and hole patterns 6 co-exist. CONSTITUTION:The phase shift photomask for transferring patterns by projection exposure onto wafers, etc., is provided with phase shift parts of a space frequency modulation type in the line pattern regions 5 of a halftone type photomask providing the surface of a transparent substrate 1 with the patterns 2 of a translucent film having a phase shift effect and light shielding effect to exposure light at the time of transferring the patterns to the wafer, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photomask used for manufacturing high-density integrated circuits such as LSI, VLSI, and VLSI, and particularly, to form and form a fine pattern on a wafer with high density. It relates to a phase shift photomask.

[0002]

2. Description of the Related Art Conventionally, in the fabrication of semiconductor integrated circuits such as ICs, LSIs and VLSIs, an original plate having a desired pattern called a reticle is used and Si coated with a resist is used.
On a processed substrate such as a wafer, a stepper or the like is used to reduce and project the pattern image of the original plate, and then develop the resist,
A lithographic process has been adopted in which a resist film having a desired pattern is formed on a processed substrate, and the processed film is etched using the resist film as a protective film. However, in recent years, with the higher integration of semiconductor integrated circuits, further miniaturization has been required for reticles used in the fabrication of these circuits. Currently, 16M DR
The line width of the device pattern transferred from the 5 × reticle for AM is as fine as 0.6 μm. 64M D
In the case of a RAM device pattern, resolution of 0.35 μm line width is required, and the conventional optical exposure method using a stepper has reached its limit. Therefore,
A phase shift photomask of a system which can improve the resolution of a device pattern transferred from a reticle in light exposure and can be used in a current stepper has been attracting attention. Regarding the phase shift photomask, JP-A-58-173744 and JP-B-62-592.
Although the basic idea and principle have already been described in No. 96, the merit that the current optical exposure system can be continued as it is is reviewed, and development of various types of phase shift photomasks will be actively studied. Has become.

Regarding the resolution in the case of projection exposure on a wafer using this phase shift photomask, the case of projection exposure using a conventional photomask without a shifter layer is taken as a comparative example, and FIG. B) will be briefly explained. FIG. 7A shows a diagram in the case of performing projection exposure with exposure light using the phase shift photomask 71. In this case, the amplitude of the light on the light output side of the mask is shown in FIG. 7B on the wafer. (C) shows the amplitude distribution of the light of, and (d) shows the intensity distribution of the light on the wafer. Also, FIG.
(A) of (b) shows a diagram in the case of projection exposure with exposure light using the conventional photomask 71a. In this case, the amplitude of the light on the light output side of the mask is (b), and the light on the wafer is shown. The amplitude distribution is shown in (c), and the light intensity distribution on the wafer is shown in (d). The phase shift photomask 71 shown in FIGS. 7A and 7A has a line-and-space pattern having a predetermined width and pitch, which is composed of a light-shielding film 73 on a transparent substrate 72.
A shifter layer 74 is provided so as to cover the alternate openings of the line-and-space pattern and the light-shielding film 73 adjacent to the openings, and the conventional photomask 71a shown in FIGS. On the transparent substrate 72a.
A line-and-space pattern having a predetermined width and pitch of 3a is provided. When the exposure light is incident on the upper shifter type phase shift photo mask 71, the amplitude of the light transmitted through the shifter portion 74 does not have a shifter on the light exit side of the mask as shown in FIGS. 7A and 7B. The amplitude and the phase of the light transmitted between the light-shielding films 73 are set to be nπ (n is an odd number) shifted and inverted. Therefore, these lights interfere with each other on the wafer, resulting in an amplitude distribution as shown in FIGS. 9A and 9C, and as a result, the light intensity on the wafer becomes as shown in FIGS. On the other hand, when the conventional photomask 71a is used, the amplitude on the light output side of the photomask is as shown in FIGS. 7B and 7B.
There is no phase shift between them, and they interfere with each other, and
(B) The amplitude distribution is as shown in (c), and as a result, the light intensity on the wafer is as shown in (b) and (d) of FIG. 7. In the case of FIGS. 7 (a) and 7 (d), there is a portion where the light intensity becomes zero between the peaks of the light intensity distribution, whereas in the case of FIG. It can be seen that it is in a spread state. That is, regarding the resolution of the resist on the wafer, the light intensity distributions of FIGS.
It can be seen that (b) is superior to the intensity distribution of (d).
In the above, the thickness of the shifter portion 74 has a phase difference of nπ
(N is an odd number) It is ideal to shift them, and the phase shift effect is the largest, but nπ−π / 3 to nπ + π / 3
Even in the range of (n is an odd number), it is effective in improving resolution.

Various types of phase shift photomasks have been proposed, and typical phase shift photomasks include a halftone type, a spatial frequency modulation type, and an auxiliary shifter type. There are various types of phase shift photomasks, but in both cases, compared to conventional photomasks that do not use a shifter layer, when transferring to a wafer,
The principle of improving the resolution is basically the same as that shown in FIG. In the halftone type, as shown in the cross section of FIG. 9A, a semitransparent film pattern 91 having both a phase shift effect and a light blocking effect on exposure light is provided on a glass substrate 90. The semi-transparent film pattern 91 may be a substantially single layer, or may be a multi-layer in which different layers have a phase shift effect and a light shielding effect. However, it is a feature of this type that in each case it consists of only one pattern. The spatial frequency modulation type is shown in FIG.
As shown in (b), the phase shift pattern 93A made of a transparent film and the light shielding layer pattern 94A are separately arranged on the transparent substrate 90A. This type is generally effective in a line & space pattern, and the transparent substrate 90
A light-shielding layer pattern 94A is formed on A, and the openings 95A of the light-shielding layer pattern 94A are alternated with each other by the phase shift pattern 93.
It is covered with A. In the case of this type, the light shielding layer pattern 9
4A and the phase shift pattern 93A are different patterns. As shown in FIG. 9C, the auxiliary shifter type is arranged along the opening 95B of the light-shielding layer pattern 94B for obtaining a desired pattern, and the light-shielding layer opening 96 which is not resolved during projection exposure onto a wafer or the like. And the phase shifter pattern 93B is provided in the opening 96, the opening 96,
Auxiliary pattern 97 together with the phase shifter pattern 93B
Say This type is particularly effective for hole patterns.

The above-mentioned cases of the spatial frequency modulation type and the auxiliary shifter type are almost the same as those shown in FIG. 7, and the description of the resolution is omitted. In the case of this halftone type, the resolution at the time of transfer will be briefly described by comparison with a conventional photomask not using a shifter layer. As shown in FIG. 8, when the exposure light is incident on the halftone type phase shift photomask 81, the light transmitted through the semitransparent film 82 is exposed on the mask light output side as shown in FIGS. 8A and 8B. The amplitude of is shifted by nπ (n is an odd number) from the amplitude of the light transmitted through the semitransparent film 83 having no shifter, and is set to be inverted. Therefore, an amplitude distribution in which these lights interfere with each other is produced on the wafer, and as a result, FIG.
The light intensity distribution is as shown in (c). On the other hand, in the case of the conventional photomask, when the exposure light is incident on the photomask 81A, the light does not reach the wafer from the light shielding portion 84 on the light exit side of the mask, and the photomask of FIG. As described above, since only the light that has passed through the light transmitting portion 83A reaches the wafer, the light intensity distribution on the wafer is as shown in FIG.
(B) It becomes like (c). As a result, in the case of the half-toe type, the light from the light transmitting portion 83 increases the contrast of the light intensity on the wafer due to the influence of the phase-shifted light from the semitransparent film 82, and as a result, the resolution is improved. I understand that Even in the case of the halftone type, it is ideal that the thickness of the semitransparent film 82 is shifted by a phase difference of nπ (n is an odd number), and the phase shift effect is the largest, but nπ−π / 3. Even in the range of up to nπ + π / 3 (n is an odd number), the resolution is effectively improved.

Further, FIGS. 9B and 9C show a structure in which the phase shifter patterns 93A and 93B are provided on the light shielding layer pattern. Such a structure is called an upper shifter type, and FIG.
As in (d) and (e), the structure in which the phase shifter patterns 93C and 93D are provided under the light shielding layer pattern is called a lower shifter type. In the phase shift photomask of the present invention, one having a shifter pattern provided on the semitransparent film pattern is hereinafter referred to as an upper shifter type, and one having a shifter pattern provided below the semitransparent film pattern is referred to as a lower shifter type.

However, the halftone phase shift photomask has a strong pattern shape dependency when projected and exposed. For this reason, it is effective in the hole-based pattern, but not in the line-based pattern, and when the hole-based pattern and the line-based pattern are mixed in the same mask, a fine line-based pattern is generated after projection exposure. There is a problem that it is not resolved. On the other hand, the spatial frequency modulation type phase shift photomask is effective for the line pattern, but cannot support the hole pattern. When a hole-based pattern and a line-based pattern are mixed in the same mask, it is possible to use an auxiliary shifter type phase shift photomask in order to correspond to both the hole-based pattern and the line-based pattern,
It is practically difficult to accurately create the auxiliary pattern, which has been a problem.

[0008]

Under the above circumstances, the present invention is directed to a phase shift photomask in which both fine hole-based patterns and line-based patterns are mixed on one mask. Further, it is an object of the present invention to provide a mask capable of improving both the resolution of the resist image on the wafer of both patterns, as compared with the conventional photomask which does not use the phase shift layer.

[0009]

A phase shift photomask of the present invention is a phase shift photomask for performing pattern transfer onto a wafer or the like by projection exposure, and is an exposure light for performing pattern transfer onto a wafer or the like. On the other hand, in the halftone phase shift photomask in which the pattern of the semitransparent film having the phase shift effect and the light blocking effect is provided on the transparent substrate, the spatial frequency modulation type phase shift part is provided in the line pattern area. It is characterized by that. The exposure light transmittance of the semitransparent film is 5% to 10%. Further, the phase shift photomask of the present invention is formed by providing the above-mentioned spatial frequency modulation type phase shift portion with a transparent film having a phase shift effect for exposure light when performing pattern transfer to a wafer or the like. The transparent film has an exposure light transmittance of about 100%. Further, the phase shift photomask of the present invention is such that the above-mentioned spatial frequency modulation type phase shift section has a transparent substrate section so that it has a phase shift effect on exposure light when performing pattern transfer to a wafer or the like. It is characterized in that it is formed by providing a recess in the. Incidentally, the semitransparent film having the phase shift effect and the light shielding effect referred to here is a semitransparent film composed of a single layer having the phase shift effect and the light shielding effect, and a transparent film having the phase shift effect but not the light shielding effect. And a semi-transparent film having a light-shielding effect but not having a phase shift effect, and a semi-transparent film having a plurality of films having a phase-shift effect and a light-shielding effect. Also, the transparent film as the phase shift portion includes all of a single-layer transparent film having a phase shift effect and a transparent film having a plurality of layers having a phase shift effect.

In the phase shift photomask of the present invention, the semitransparent film pattern of the halftone type phase shift photomask is used as the spatial frequency type light shielding layer pattern in the line pattern area of the mask to form the phase shift portion. Thus, even when both fine hole-based patterns and line-based patterns are mixed in one mask, this is effective in improving the resolution of both. Hereinafter, the phase shift photomask of the present invention will be described with reference to FIG. 1A to 1C are sectional views of the phase shift photomask of the present invention. FIG. 1D is a plan view thereof. FIG. 1A shows a structure in which a transparent film pattern 3 having a phase shift amount of approximately nπ radians (n is an odd number) is disposed on a semitransparent film pattern 2 having a phase shift amount of approximately nπ radians (n is an odd number). . FIG. 1B shows a structure in which a semitransparent pattern 2A having a phase shift amount of approximately nπ radians (n is an odd number) is disposed on a transparent film 3A having a phase shift amount of approximately nπ radians (n is an odd number). FIG. 1 (c) shows a case in which the recess 4 is formed in the transparent substrate 1B in the opening of the semitransparent film pattern 2B, and the phase difference from the opening in which the recess is not formed is approximately nπ radians (n is an odd number). . In the case of the structure shown in FIG. 1A, first, a semitransparent film pattern 2 having a phase shift amount of approximately nπ radians (n is an odd number) is formed, and is used as it is in the hole system pattern region 6, and is used in the line system pattern region 5. Is a transparent film pattern 3 having a phase shift amount of approximately nπ radians (n is an odd number) and alternating (every other one) openings 7 of the semitransparent film pattern 2 having a phase shift amount of approximately nπ radians (n is an odd number). It was done. Also, FIG. 1 (b)
In the case of the structure shown in FIG. 1, first, a transparent film 3A having a phase shift amount of approximately nπ radians (n is an odd number) is formed, and a semitransparent film pattern 2 having a phase shift amount of approximately nπ radians (n is an odd number) is formed thereon.
A is then formed in the hole system pattern region 6A, and in the line system pattern region 5A, only a predetermined opening of the semitransparent film pattern 2A having a phase shift amount of approximately nπ radians (n is an odd number) is exposed. The transparent film 3A having a phase shift amount of about nπ radians (n is an odd number) is to be removed, and the removal position is every other opening 7A. In the case of the structure shown in FIG. 1C, first, a semitransparent film pattern 2B having a phase shift amount of approximately nπ radians (n is an odd number) is formed on the transparent substrate 1B, and then the hole-based pattern region 6 is formed.
In the line system pattern region 5B, the phase shift amount is selectively shifted by about nπ radian (n is an odd number) relative to the adjacent opening in the line-shaped pattern region 5B, as it is in B. Thus, the concave portion 4 is formed. The recesses 4 are formed at every other opening 7B. As described above, in the spatial frequency type phase shift part of the phase shift photomask of the present invention, the line pattern part made of a semitransparent film is used as a light shielding pattern, and a transparent film is provided at every other opening of the light shielding pattern. The arrangement or the transparent substrate is provided with a recess, and the amount of phase shift relative to the exposure light is approximately nπ radians (n is an odd number) relative to the adjacent opening. Practically, the phase shift amount is generally set to approximately π radian relative to the adjacent opening.

In the spatial frequency type phase shift portion of the phase shift photomask of the present invention, the shift (difference) in the phase shift amount of the transmitted light relative to the adjacent exposure light with respect to the exposure light is nπ radian as much as possible. A value closer to (n is an odd number) is more effective, and a value closer to 100% to the exposure light in the phase shift section is more effective. Further, as described above, the semitransparent film of the phase shift photomask of the present invention has a transmittance of exposure light of 1 to 50% and an amount of phase shift of the exposure light in order to function as a halftone type phase shift photomask. φ is effective when nπ−π / 3 <φ <nπ + π / 3, but normally 5 of 16 to 64 MDRAM level.
For double reticle, 5 for hole pattern
It is said that the one having a transmittance of -10% and the one having a transmittance of 1-6% are particularly effective for a line pattern.
Therefore, in order to make both the hole-based pattern and the line-based pattern particularly effective, as the semitransparent film of the phase shift photomask of the present invention, one having an exposure light transmittance of 5 to 10% is used, and With respect to the spatial frequency type phase shift section, the shift (difference) of the transmitted light relative to the exposure light relative to the exposure light is as much as nπ radian (n).
Is an odd number), and the transmittance for the exposure light in the phase shift portion needs to be as close to 100% as possible.

FIGS. 4 to 6 show simulation results of the exposure light intensity distribution on the wafer when the line-type pattern in the photomask is projected and exposed on the wafer. 4 shows a case of a halftone type phase shift photomask, FIG. 5 shows a case of the upper shifter type of the present invention, and FIG. 6 shows a case of the lower shifter type of the present invention. In addition, the light intensity distribution simulator F TREPTON is used for the simulation.
2 (manufactured by Fuji Sogo Laboratories) and the light source is i-line (365n
m) and just focus was performed. FIG. 4 shows a light intensity distribution on a wafer having a line-and-space pattern with a wafer size of 0.35 μm in the halftone type. At this time, the i-line transmittance of the translucent film pattern portion is 5%,
The amount of phase shift was set to 180 °. FIG. 5 shows the light intensity distribution on the wafer when the transparent film patterns are arranged alternately (every other opening) on the line & space pattern of the semitransparent film on the reticle, which has a wafer size of 0.35 μm. The transparent film pattern is arranged from the center to the center of the semitransparent film pattern. At this time, the i-line transmittance of the transparent film pattern portion is 100%, the phase shift amount is 180 °, and the i-ray transmittance of the semitransparent film pattern portion is 5%.
% And the phase shift amount was set to 180 °. FIG. 6 shows a light intensity distribution on a wafer when a line and space pattern of a semitransparent film having a wafer size of 0.35 μm is arranged on the transparent film pattern. At this time, the i-line transmittance of the transparent film pattern portion was 100%, the phase shift amount was 180 °, the i-ray transmittance of the semitransparent film pattern portion was 5%,
The amount of phase shift was set to 180 °. From these results, it is possible to transfer the pattern to the wafer having high contrast in the line pattern by using the phase shift photomask of the present invention as compared with the conventional halftone type. Further, the phase shift photomask of the present invention does not have a minute pattern required for the auxiliary shifter type, and therefore can be easily manufactured.

[0013]

The shifter type phase shift photomask of the present invention has such a construction that projection exposure can be performed even when both fine hole-based patterns and line-based patterns are mixed on one mask. It is possible to improve both pattern resolution of the resist on the wafer obtained by the method compared to the conventional photomask that does not use a shifter.The resolution of the line pattern is improved compared to the conventional halftone type. In comparison with the conventional spatial frequency modulation type, the resolution of the hole pattern is increased. Further, the shifter type phase shift photomask of the present invention does not require a fine pattern unlike the auxiliary shifter type, and thus the manufacture thereof is facilitated by having such a structure. After all, the shifter type phase shift photomask of the present invention has such a configuration that even in a mask in which various fine patterns are mixed,
This makes it possible to transfer various fine patterns onto a wafer, and as a result, further miniaturization of semiconductor integrated circuits can be promoted.

[0014]

Embodiment 1 Embodiment 1 of the present invention will be described below with reference to FIG. FIG. 2A is a diagram for explaining the phase shift photomask for i-line exposure and the manufacturing process thereof according to the first embodiment. On the synthetic quartz substrate 21 for photomask, an etching stopper layer 22 of a shifter layer mainly composed of tin oxide was sputter-deposited to a thickness of about 20 nm under the following conditions. The sputtering conditions were as follows. Method: DC magnetron sputter target: Tin oxide (containing 5 atmm% antimony oxide) Gas and pressure: Argon, 100 sccm, 5 mt
orr Substrate temperature: about 200 ° C. Then, spin-on glass (Acuglass 211S manufactured by Allied Signal Co., Ltd.) is applied by spin coating,
Immediately bake at 400 ° C in an air atmosphere, and atssa 39
A 0 nm phase shift layer 23 was obtained. Next, on the phase shift layer 23, the light shielding layer 24 is provided with a light wavelength of 365 nm under the following conditions.
A film was formed so that the transmittance at 5% was 5% to obtain a halftone type phase shift photomask blank 20.
((A) of FIG. 2 (a)) Method: DC magnetron sputter target: Chromium gas and pressure: Argon, 100 sccm, 3 mt
orr Substrate temperature: A resist pattern was formed on the blanks 20 by a conventional electron beam lithography method without heating, and the chromium layer in the portion where the resist was removed was selectively removed under the following conditions. Method: Parallel plate RF reactive ion etching target: Sichloromethane 60 sccm + oxygen 40 sccm, 10 mtorr Subsequently, the spin-on-glass layer was etched under the following conditions. Method: Parallel plate RF reactive ion etching target: Carbon tetrafluoride 80 sccm + oxygen 2
0 sccm, 10 mtorr After that, the resist was peeled off to obtain a mask 25 having both a hole system and a line system ((b) of FIG. 2A). The mask 25 is also a halftone type phase shift photomask. Then, spin-on glass was applied onto the mask 25 again by a spin coating method to obtain a shifter layer 26 shown in (c) of FIG. 2A with a thickness of 390 nm.
The shifter layer 26 is patterned by a conventional electron beam lithography so that the line pattern portion is of a spatial frequency modulation type in which the halftone phase shift layer serves as a light shielding layer. At this time, the phase shift layer 26 in the hole portion
Can also be removed. The phase shift layer 26 was removed under the same conditions as the etching of the shifter layer 23. As described above, the phase shift photomask 27 of Example 1 was obtained ((d) of FIG. 2A). In the obtained phase shift photomask 27, the light shielding layer 24 and the shifter layer 23 form a semitransparent layer having a phase shift effect and a light shielding effect. The light shielding layer 24 and the shifter layer 23 are paired. The halftone type phase shift photomask formed of a semitransparent film pattern has a phase shift portion 26S formed at every other opening of the line system pattern portion, which is an upper shifter type.

Next, a modification of the first embodiment will be described with reference to FIG. The phase shift photomask 27A shown in FIGS. 1B and 1B has a phase shift effect and a light shielding effect made of a chromium-based or Mo-based metal compound or mixture or a ceramic-based material on a transparent substrate 21A made of quartz or the like. The single layer semi-transparent film 28 may be used to form the phase shift portion 26SA made of the SOG film in the same manner as in the above embodiment. In the case of the semitransparent film 28 made of a chromium-based or Mo-based metal compound or mixture, it can be prepared by sputtering, vapor deposition, etc., and its patterning is easy, and it can be said that it is practical from Example 1. .

A second embodiment of the present invention will be described below with reference to FIG.
I will explain along (a). FIG. 3A shows a phase shift photomask for i-line exposure and its manufacturing process according to the second embodiment. A halftone phase shift photomask blank 30 (FIG. 3 (a) (a)) which is the same as that of the first embodiment except that the etching stopper layer is not included is used. A shift photo mask 35 was created ((b) of FIG. 3 (a)). However, etching of the spin-on glass was performed by wet etching with a buffered hydrofluoric acid solution. A usual electron beam resist was applied onto the halftone phase shift photomask 35, and the resist of the line pattern portion was patterned in the same manner as in Example 1 by a conventional method ((c) of FIG. 3 (a)). ). Subsequently, the synthetic quartz substrate 31 in the portion where the resist is selectively removed under the following conditions is etched by a depth of about 390 nm under the following conditions to form the recess 3
Formed 7. Method: Parallel plate RF reactive ion etching target: Carbon tetrafluoride 80 sccm + oxygen 2
0 sccm, 10 mtorr The phase shift photomask 39 of Example 2 was obtained by the above (FIG.3 (d)). Obtained phase shift photomask 2
9 is a semi-transparent layer having a phase shift effect and a light shielding effect, which is formed by the light shielding layer 34 and the shifter layer 33.
A recess 37 is formed as a phase shift portion at every other opening of the line type pattern portion of the halftone type phase shift photomask 35 formed of a semitransparent film pattern in which the light shielding layer 34 and the shifter layer 33 are paired. is there.

In the case of Example 2 as well, as shown in FIG. 2B, a single-layer half-layer made of a chromium-based or Mo-based metal compound or mixture or a ceramic-based material having a phase shift effect and a light blocking effect. A modified example is a phase shift photomask 39A in which the transparent film 38 is used to form recesses 37A in every other line pattern opening in the line pattern area formed of the semitransparent film 38. When the semi-transparent film 28 made of a chromium-based or Mo-based metal compound or mixture is used, it can be prepared by sputtering, vapor deposition, etc., and its patterning is easy, so that it is more practical than the second embodiment. I can say.

[0018]

As described above, the present invention provides an LSI, an ultra-L.
It is possible to provide a phase shift photomask that can meet the demands for miniaturization and high integration of SI, ultra-VLSI, etc. Specifically, in the mask of the present invention, a line-based pattern is formed on one mask. Even in the case where the hole pattern and the hole pattern are mixed, the resolution of both patterns on the wafer can be improved as compared with the conventional photomask which does not use the phase shifter layer. The manufacture of such a mask is relatively simple and practical, and is suitable for miniaturization of integrated circuits.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a phase shift photomask of the present invention.

FIG. 2 is a process schematic diagram for explaining the first embodiment of the present invention.

FIG. 3 is a process schematic diagram for explaining a second embodiment of the present invention.

FIG. 4 is a simulation diagram of a conventional photo mask.

FIG. 5 is a simulation diagram of a phase shift photomask of the present invention.

FIG. 6 is a simulation diagram of a phase shift photomask of the present invention.

FIG. 7 is a diagram for explaining resolution when a phase shift photomask is used.

FIG. 8 is a diagram for explaining resolution when a halftone phase shift photomask is used.

FIG. 9 is a diagram for explaining a conventional phase shift photomask.

[Explanation of symbols]

1, 1A, 1B Transparent substrate (synthetic quartz substrate) 2, 2A, 2B Semi-transparent film pattern 3 Transparent film pattern 3A Transparent film 4 Recesses 5, 5A, 5B Line system pattern regions 6, 6A, 6B Hole system pattern region 7, 7A, 7B Opening 20, 20A Blanks for halftone type phase shift photomask 21, 21A Transparent substrate (synthetic quartz substrate) 22 Etching stopper layer 23 Shifter layer 24, 24A Light shielding layer 25 Halftone type phase shift photomask 26 Shifter layer (SOG film) 26S, 26SA Phase shift part 27, 27A Phase shift photomask 28 Semitransparent film 30 Halftone type phase shift photomask blanks 31 Transparent substrate (synthetic quartz substrate) 33 Shifter layer 34 Light shielding layer 35 Halftone type phase mask Shift photo mask 36 Gist 37, 37A Recessed portion 38 Semi-transparent film 39 Phase shift photo mask 71 Phase shift photo mask 71a Conventional photo mask 72, 72a Transparent substrate 73, 73a Light-shielding film 74 Shifter layer 81 Halftone type phase shift photo mask 81A Conventional photo mask 82 Half Transparent film 83, 83A Light transmission part 84 Light shielding film 90, 90A, 90B, 90C, 90D Transparent substrate 91 Semitransparent film 93A, 93B, 93C, 93D Phase shift pattern 94A, 94B, 94C, 94D Light shielding layer pattern 95A, 95B Opening Part 96 Opening 97, 97D Auxiliary pattern

Claims (5)

[Claims] 1. A phase-shifting photomask for performing pattern transfer onto a wafer or the like by projection exposure, which has a phase-shifting effect and a light-shielding effect on exposure light when performing pattern transfer onto a wafer or the like. A phase shift photomask comprising a halftone type phase shift photomask having a transparent film pattern provided on a transparent substrate, wherein a spatial frequency modulation type phase shift part is provided in a line pattern area. 2. The phase shift photomask according to claim 1, wherein the semitransparent film has an exposure light transmittance of 5% to 10%. 3. The spatial frequency modulation type phase shift section according to claim 1 or 2 is formed by providing a transparent film having a phase shift effect for exposure light when a pattern is transferred to a wafer or the like. A phase shift photomask characterized by the following. 4. The phase shift photomask according to claim 3, wherein the transparent film has an exposure light transmittance of about 100%. 5. The spatial frequency modulation type phase shift part according to claim 1 or 2 has a phase shift effect on exposure light when a pattern is transferred to a wafer or the like,
A phase shift photomask characterized by being formed by providing a recess in a transparent substrate portion.