JP2002372775A - Method of manufacturing blank for phase shift mask, method of manufacturing phase shift mask and blank for phase shift mask - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a blank for a phase shift mask which is capable of improving the yield of production. SOLUTION: This method has a process step of forming a first shifter film 12 on one surface of a transparent substrate 10, a process step of forming a second shifter film 14 on another surface of the transparent substrate 10, a process step of carrying out the defect inspection of at least one shifter film of the first shifter film 12 and the second shifter film 14 and a process step of forming a light shielding film on the shifter film on the side of the first shifter film 12 and the second shifter film 14, which side satisfies standards.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a blank for a phase shift mask, a method for manufacturing a phase shift mask, and a blank for a phase shift mask according to the photolithography technique.

[0002]

2. Description of the Related Art Today's prosperity of microelectronics has been achieved by improving the degree of integration of LSIs, that is, by miniaturizing elements, and is largely due to the evolution of lithography. Lithography includes light, electron beam, X
Methods using various beams, such as ion beams and ion beams, have been devised. Among these, optical lithography has been widely used for mass production. A phase shift mask has been proposed as one technique for improving the resolution of the photolithography.

As a phase shift mask, a Levenson type in which light transmitted through mask openings corresponding to adjacent patterns is made to have an opposite phase to each other, or a light-shielding part having transparency and a phase of light transmitted through the light-shielding part is used. And a halftone type in which the phase is opposite to the phase of the light transmitted through the opening. As described above, the phase shift mask aims to improve the resolution by positively utilizing the phase difference of light.

Incidentally, a transparent substrate provided with a shifter film, a light shielding layer, and the like for manufacturing a phase shift mask is generally called a blank for a phase shift mask. The phase shift mask can be manufactured by patterning the light shielding film and the shifter film of the blank for the phase shift mask into a predetermined pattern. In a conventional method of manufacturing a blank for a phase shift mask, first, a shifter film is formed on a transparent base material, and a defect inspection of the shifter film is performed. A film is formed. If a phase shift mask is created in a state where the shifter film has a defect caused by a foreign substance or the like, a phase defect may be caused at the time of exposure. Generally, a phase shift mask is applied in a process in which a pattern is difficult to be formed in a lithography process in a manufacturing process of a semiconductor device, and a blank for a phase shift mask is naturally required to have a low defect density. For this reason, when a defect that does not satisfy a predetermined standard is found in the shifter film in the defect inspection, it must be determined to be defective before the light-shielding film is formed. In order to regenerate the defective phase shift mask blank, it is necessary to peel off the shifter film and re-polish the surface of the transparent substrate with high accuracy.

[0005]

However, in order to regenerate a defective phase shift mask blank by the above-described method, an advanced technique is required particularly in the step of repolishing the transparent substrate. Since it takes a lot of man-hours and time, it is not realistic to reproduce a defective product and produce a completely good blank for a phase shift mask.

Therefore, a blank for a phase shift mask which has become defective based on a defect inspection of a shifter film cannot be applied to a phase shift mask of optical lithography used in trial production and mass production of semiconductor devices, and is used for test exposure and the like. Need to be applied to the mask or discarded. Since phase shift mask blanks are considerably more expensive than ordinary mask blanks, lowering the yield increases the cost of the phase shift mask, which may have a significant effect on the profits of the semiconductor business.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a method of manufacturing a phase shift mask blank, a method of manufacturing a phase shift mask, and a phase shift mask blank capable of improving the manufacturing yield. The purpose is to provide.

[0008]

In order to solve the above problems, the present invention relates to a method for manufacturing a blank for a phase shift mask, comprising the steps of: forming a first shifter film on one surface of a transparent substrate; Forming a second shifter film on the other surface of the transparent substrate, performing a defect inspection on at least one of the first shifter film and the second shifter film, and performing the defect inspection Based on the result of
Forming a light-shielding film on the shifter film that satisfies a predetermined criterion among the shifter film and the second shifter film described above.

According to the present invention, first, a first shifter film and a second shifter film are formed on one surface and the other surface of a transparent substrate, respectively. Thereafter, for example, a defect inspection of the first shifter film formed on one surface of the transparent substrate is performed to check whether a defect due to a foreign substance or the like has occurred in the first shifter film. If the inspection result satisfies a predetermined criterion, a light shielding film is formed on the first shifter film.

On the other hand, if the inspection result does not satisfy the predetermined standard, the following steps are performed. That is, a defect inspection of the second shifter film formed on the other surface of the transparent substrate is performed, and whether the second shifter film has a defect is inspected. If this test result satisfies the predetermined criteria,
A light shielding film is formed on the second shifter film. Conventionally, a shifter film is formed only on one surface of a transparent substrate and a defect inspection of the shifter film is performed. If the inspection result does not satisfy a predetermined standard, the transparent substrate is regarded as a defective product. However, according to the present invention, the second surface is also provided on the other surface of the transparent substrate.
Is formed, and the second shifter film is inspected for defects. If the inspection result satisfies a predetermined criterion, the second shifter film is inspected.
By forming a light shielding film on the shifter film, a mask blank for a phase shift mask can be manufactured.
That is, even if a defect occurs in the first shifter film and the defect inspection result does not satisfy the predetermined standard, if the defect inspection result of the second shifter film satisfies the predetermined standard, the shifter film is provided. The transparent substrate does not become a defective product, and a completely good blank for a phase shift mask can be manufactured.

By doing so, the defective rate of the transparent substrate provided with the shifter film can be reduced, and the production yield of blanks for a phase shift mask can be improved. Further, in order to solve the above problem, the present invention relates to a method for manufacturing a blank for a phase shift mask, comprising: forming a first shifter film on one surface of a transparent substrate; Performing a test and forming a light-shielding film on the first shifter film if the defect inspection satisfies a predetermined criterion, or the other of the transparent substrates if the predetermined criterion is not satisfied. Forming a second shifter film on the surface of the second shifter film, performing a defect inspection on the second shifter film, and forming a light-shielding film on the second shifter film when the defect inspection satisfies the predetermined standard. And a process.

According to the present invention, first, a first shifter film is formed on one surface of a transparent substrate. Thereafter, a defect inspection of the first shifter film is performed, and when the inspection result satisfies a predetermined standard, a light-shielding film is formed on the first shifter film. On the other hand, if the inspection result does not satisfy the predetermined criterion, a second shifter film is formed on the other surface of the transparent substrate, and the second shifter film is formed.
Of the shifter film is inspected. If the inspection result satisfies a predetermined standard, a light shielding film is formed on the second shifter film.

According to the present invention, similarly to the above-described method of manufacturing a blank for a phase shift mask, the defect rate of a transparent substrate having a shifter film can be reduced, and the manufacturing yield of the blank for a phase shift mask can be improved. be able to. In a preferred embodiment, in the method for manufacturing a phase shift mask blank described above, the transmittance of the light-shielding film is 0%.
% To 30%.

As the light-shielding film used for the Levenson-type phase shift mask blank, a light-shielding film having a light transmittance of 0% or close to it, that is, a light-shielding film that almost blocks light can be used. On the other hand, a light-shielding film used for a halftone-type phase shift mask blank needs to have a certain degree of light transmittance. Therefore, the upper limit of the transmittance is about 30%, preferably about 6%. A translucent material may be used.

[0015]

Embodiments of the present invention will be described below with reference to the accompanying drawings. (First Embodiment) FIG. 1 is a schematic sectional view showing a method for manufacturing a phase shift mask blank according to a first embodiment of the present invention, and FIG. 2 is a method for manufacturing the phase shift mask blank shown in FIG. 5 is a process flow chart for explaining the process.

A description will be given along the flowchart of FIG. 2 while appropriately referring to the schematic sectional view shown in FIG. (Manufacturing Method of Levenson-Type Blank for Phase Shift Mask) The manufacturing method of the blank for phase-shift mask (Levenson type) according to the embodiment of the present invention is as follows.
As shown in FIG. 1 and FIG. 1 (step a), a transparent glass substrate 10, which is an example of a transparent substrate, is prepared. This glass substrate 1
0, for example, 6 inches square (152.4 × 152.
4 mm) with a thickness of 0.25 inches (6.
35 mm) can be used.

Thereafter, as shown in S12 of FIG. 2 and FIG. 1 (step b), SOG of silazane-based inorganic material is applied on one surface of the glass substrate 10 so as to have a coating thickness of, for example, 400 nm. The liquid is applied to form a coating film.
Subsequently, the SOG coating film was treated at a temperature of 400 ° C. for 0.1 mm.
By performing heat treatment for 3 hours while flowing 5 cc of water (H ₂ O), a first SOG film 12 as an example of a first shifter film is formed.

Here, an SOG film which is a shifter film used for a Levenson type phase shift mask will be described. In the case of the Levenson type, by changing the phase of light emitted from the adjacent openings by 180 °, the diffracted lights cancel each other out due to negative interference, and the images of the openings can be separated from each other. In order to invert the phase of the opening, an optical path difference may be provided by providing a transparent substance (shifter film) having a thickness d and a refractive index n every other opening. That is, assuming that the exposure wavelength is λ, the shifter film (SO
If the thickness d of the (G film) is given by d = λ / 2 (n−1), a phase difference of 180 ° can be obtained. In the present embodiment, the thickness of the first SOG film 12 as the shifter film is 2
It is set to about 80 nm.

Next, as shown in FIG. 1 (step b), the first S
A second SOG film 14, which is an example of a second shifter film, is formed by a method similar to the method of forming the OG film 12. By forming the same SOG film on both surfaces of the glass substrate 10 as described above, the stress of the SOG film is reduced as compared with the case where the SOG film is formed on only one surface. Can be improved in flatness.

Next, the process proceeds to S14 in FIG. 2, for example, a defect inspection of the first SOG film 12 is performed. As the types of defects of the SOG film, there are protruding defects of the SOG film in which foreign matter in the air attached to the glass substrate is a nucleus, and defects caused by bubbles generated during application of the SOG coating solution. As a device for detecting such a defect of the SOG film, a foreign matter inspection device having a laser confocal optical system or the like can be used, and the defect of the SOG film can be easily detected. Here, as an example of the criterion of the defect inspection, an arrangement may be made such that when one or more foreign substances having a diameter of 1.0 μm are detected, the criterion is not satisfied. The standard for this defect inspection may be appropriately adjusted depending on the type of the mask blanks and the like.

At this stage, in S14 of FIG. 2, the first SO
When the defect inspection result of the G film 12 satisfies the predetermined criterion (Yes), the process proceeds to S16, and a Cr (chromium) film 16 having a thickness of, for example, 100 nm, which is an example of a light shielding film, is formed on the first SOG film 12. The film is formed by a sputtering method or the like. At this time, as described above, since the flatness of the glass substrate 10 is good, the Cr film 16 is stably formed with a small stress. The Cr film 16 used in the Levenson-type phase shift mask has a transmittance of 0% or close to it, that is, a C film having a function of almost blocking light.
It is preferable to form an r film.

As a result, as shown in FIG. 1 (step c), a first SOG film 12 and a second SOG film 14 are formed on one surface and the other surface of the glass substrate 10, respectively. Cr film 16 is formed on first SOG film 12. As a result, Levenson-type phase mask blanks 30 that are completely non-defective products are manufactured. On the other hand, S
If the result of the defect inspection of the first SOG film 12 does not satisfy the predetermined criterion (No), as shown in FIG. 1 (step d), a defect 20 occurs in the first SOG film 12a. Will be. Then, the process proceeds to S18, where the glass substrate 10
The second SOG film 14 formed on the other surface is inspected for defects. If the inspection result satisfies the predetermined criterion (Yes), the process proceeds to S20 in FIG. 2 and a Cr film 16 is formed on the second SOG film 14 as shown in FIG.

As described above, in S14, the first SOG film 1
If the defect inspection result of 2a does not satisfy the predetermined criterion, a defect inspection of the second SOG film 14 is performed, and if the inspection result satisfies the predetermined criterion, a Cr film is formed on the second SOG film 14. By forming 16, a blank 30 a for a phase mask which is a completely non-defective product can be manufactured. Note that a resist film (not shown) for an electron beam may be applied on the Cr film 16 of the phase mask blank (30, 30a), and this may be used as a phase shift mask blank.

In step S20, when the Cr film 16 is formed to form the phase shift mask blanks 30a, the defect 20 is generated on the surface of the glass substrate 10 opposite to the surface on which the Cr film 16 is formed. The remaining first SOG film 12a remains. However, this phase mask blank 3
When 0a is used as a phase shift mask, the light is focused on the Cr film 16 during exposure, so that the first SOG film 12a
Is not transferred onto the wafer.

If the defect inspection result in S18 does not satisfy the predetermined criterion (No), as shown in FIG.
Since the defect 20 has occurred in both the first SOG film 12a and the second SOG film 14a formed on one and the other surfaces of the glass substrate 10, the process proceeds to S22 and the glass substrate 10 is removed. Defective. In the present embodiment, an example in which the defect inspection of the first SOG film 12 is performed first is illustrated, but it goes without saying that the defect inspection of the second SOG film 14 may be performed first.

According to the method of manufacturing a blank for a phase shift mask of the present embodiment, when the defect inspection result of the first SOG film 12a formed on one surface of the glass substrate 10 does not satisfy a predetermined standard. However, if the glass substrate 10 does not become defective and the second SOG film 14 formed on the other surface of the glass substrate 10 is inspected again, and if the inspection result satisfies a predetermined standard, the second inspection is performed. C on the SOG film 14
By forming the r film 16, blanks for a phase shift mask can be manufactured.

By doing so, the defect rate of the glass substrate provided with the shifter film can be reduced, and the production yield of the phase shift mask blank can be improved. Thereby, the cost of the blank for the phase shift mask can be reduced. (Manufacturing method of halftone type phase shift mask blank) In order to manufacture a halftone type phase shift mask blank, the Cr film 16 formed by the above-described Levenson type phase shift mask blank manufacturing method is used. Instead, a translucent Cr film having a light transmittance of preferably about 6% and a thickness of, for example, 270 nm may be formed. The transmittance is not limited to this, and may be lower than 6%, or higher than 6%, and may be up to about 30%.

As described above, in the halftone type, for example, the two-layer structure of the SOG film as the shifter film and the translucent Cr film is made to correspond to the light shielding portion of the normal mask. The two-layer structure is set to have an optical constant such that the phase is inverted with respect to the light passing through the opening.
(Method of Manufacturing Levenson-Type Phase Shift Mask) FIG.
(A)-(d) is schematic sectional drawing which shows the manufacturing method of the phase shift mask of a Levenson type.

In the method for manufacturing a Levenson-type phase shift mask according to an embodiment of the present invention, first, as shown in FIG. 3A, the Levenson-type phase shift mask blank was manufactured by the above-described method for manufacturing a Levenson-type phase shift mask blank. A blank 30a for a phase shift mask is prepared. In the present embodiment, S in FIG.
20, an embodiment using a phase shift mask blank on which a Cr film 16 is formed will be described as an example. That is, on the surface of the glass substrate 10 opposite to the surface on which the Cr film 16 is formed, as shown in FIG. 1 (step d), the first SOG film 12a having the defect 20 is formed. Use things.

Thereafter, as shown in FIG. 3A, a resist film for an electron beam is applied on the Cr film 16 and an electron beam is drawn on the resist film to form a predetermined resist film pattern 18.
To form Next, as shown in FIG. 3B, by using the resist film pattern 18 as a mask, the Cr film 16 is etched by dry etching, etc.
A film pattern 16b is formed.

Next, as shown in FIG. 3C, a resist film for an electron beam is formed so that the second SOG film 14 remains at every other opening where the Cr film pattern 16b is not formed. Patterned resist film pattern 18a
To form At this time, when the second SOG film 14 is etched, the Cr film pattern 16b substantially serves as a mask, and the second SOG film 14 is etched in a self-aligned manner with respect to the Cr film pattern 16b. A resist film pattern 18a is formed so that a part of the Cr film pattern 16b is exposed.

Next, as shown in FIG. 3D, the second SOG film 1 is formed by dry etching using the resist film pattern 18a and the Cr film pattern 16b as a mask.
4 is etched to form a second SOG film pattern 14d. At this time, the etching rate of the second SOG film 14 is at least 10 times higher than the etching rate of the glass substrate 10, so that the glass substrate 10 is hardly etched.

Thus, the second SOG film 14 is formed every other opening where the Cr film pattern 16b is not formed.
(Shifter film) remains, and a Levenson-type phase shift mask 40 having a second SOG film pattern 14d in which a second SOG film 14 is opened at every other opening.
Is completed. In the present embodiment, the Cr of the glass substrate 10
An example is shown in which the first SOG film 12a in which the defect 20 has occurred remains on the surface opposite to the surface on which the film pattern 16b is formed. As mentioned earlier, even if the first
Even if the defect 20 is generated in the SOG film 12a,
At the time of exposure, light is focused on the Cr film pattern 16b, so that defects existing in the first SOG 12a are not transferred onto the wafer. For example, the defect 20 is 15 μm
Even if it is caused by a foreign matter having a size of about □, it is not transferred onto the wafer at the time of exposure, and has no adverse effect on the pattern formation on the wafer.

In step S16 of FIG. 2, a blank 30 for a phase shift mask (see FIG.
(Step c)) may be used to manufacture a Levenson-type phase shift mask. (Method of Manufacturing Halftone Phase Shift Mask) FIG.
7A to 7C are schematic cross-sectional views illustrating a method for manufacturing the halftone type phase shift mask according to the first embodiment.

First, as shown in FIG. 4A, a blank for a phase shift mask manufactured by the above-described method for manufacturing a blank for a halftone type phase shift mask is prepared. The Cr film of the phase shift mask blank is:
As described above, the translucent Cr film 26 preferably has a light transmittance of about 6%. Then, FIG.
As shown in FIG. 3A, a predetermined resist film pattern 18b is formed by patterning an electron beam resist film by a method similar to the above-described method for manufacturing a Levenson-type phase shift mask.

Next, as shown in FIG. 4B, the Cr film 26 is etched using the resist film pattern 18b as a mask to form a Cr film pattern 26a. Subsequently, as shown in FIG. 4C, the second SOG film 14 is also etched using the resist film pattern 18b as a mask, so that the second SOG film pattern 14e, which is a shifter film, and the semi-transparent film are formed. A two-layer structure composed of a certain Cr film pattern 26a is formed.

After etching the Cr film 26, the resist film pattern 18b is peeled off, and the Cr film pattern 2 is removed.
The second SOG film 14 may be etched using the mask 6a as a mask to form the second SOG film pattern 14e. Thus, the halftone type phase shift mask 40a is completed. Also in the method of manufacturing the halftone type phase shift mask, the Cr film pattern 26a of the glass substrate 10 is formed.
In this example, the first SOG film 12a in which the defect 20 has occurred remains on the surface opposite to the surface on which the pattern is formed. However, as described above, the first SOG film 12a is used for forming a pattern on a wafer. Has no adverse effect.

(Second Embodiment) FIG. 5 shows a second embodiment of the present invention.
FIG. 6 is a schematic cross-sectional view showing a method for manufacturing the phase shift mask blank of the embodiment, and FIG. 6 is a process flowchart for explaining the method for manufacturing the phase shift mask blank shown in FIG. A description will be given along the flowchart of FIG. 6 while appropriately referring to the cross-sectional view shown in FIG.

According to the second method for manufacturing a blank for a phase shift mask of the present embodiment, first, a first shifter film is formed on one surface of a glass substrate, and a defect inspection of this film is performed. When the inspection result satisfies a predetermined standard, a light-shielding film is formed on the first shifter film. On the other hand, if the inspection result does not satisfy the predetermined criterion, a second shifter film is formed on the other surface of the glass substrate. Is a method of forming a light-shielding film on the substrate.

First, in S10a of FIG. 6, FIG. 5 (step a)
As shown in FIG. 1, the same glass substrate 1 as in the first embodiment is used.
0a is prepared. Then, in S12a, FIG. 5 (step b)
As shown in FIG. 5, a first SOG film 12b, which is an example of a first shifter film, is formed on one surface of a glass substrate 10a by a method similar to that of the first embodiment so that the film thickness becomes, for example, 280 nm. To form a film.

Next, in S14a, a defect inspection of the first SOG film 12b is performed in the same manner as in the first embodiment. Next, when the defect inspection result satisfies a predetermined criterion (Yes), a Cr film 16c, which is an example of a light shielding film, is formed on the first SOG film 12b as shown in FIG. 5 (Step c). . The Cr film 16c may be formed by appropriately selecting the film characteristics described in the first embodiment according to the specifications of the Levenson-type or halftone-type phase shift mask. As a result, completely good phase shift mask blanks 30b are manufactured.

Next, the first SOG film 12b in S14a
When the defect inspection result does not satisfy the predetermined standard (No)
Will be described. The process proceeds to S18a without forming a Cr film on the first SOG film 12b, and as shown in FIG. 5 (step d), a second SOG film is formed on the other surface of the glass substrate 10a.
The film 14b is formed. Then, in S20a, the second SO
A defect inspection of the G film 14b is performed. If the defect inspection result satisfies the predetermined criterion (Yes), in S22a, FIG.
As shown in (step e), C is formed on the second SOG film 14b.
By forming the r film 16d, a perfectly good phase shift mask blank 30c is manufactured.

The second SOG film 14b in S20a
Is not satisfied with the predetermined criteria (N
o), as shown in FIG. 5 (step f), the glass substrate 10a
Of the first and second surfaces having a defect 20 on one and the other surface.
Since the SOG film 12c and the second SOG film 14c are formed, the glass substrate 10a is regarded as a defective product.

As described above, according to the second embodiment, a defect occurs in the first SOG film 12b formed on one surface of the glass substrate 10a, and the result of the defect inspection conforms to a predetermined standard. Even when not satisfied, this glass substrate 10
a is not defective, a second SOG film 14b is formed on the other surface of the glass substrate 10a, and the second SOG film 14b
If the defect inspection results satisfy the predetermined criterion, the second S
By forming the Cr film 16d on the OG film 14b,
Perfectly good blanks for phase shift masks can be manufactured.

By doing so, it is possible to improve the production yield of the phase shift mask blanks, as in the method of manufacturing the phase shift mask blanks of the first embodiment, thereby reducing the cost. Will be able to do it. Using the phase shift mask blanks manufactured by the above manufacturing method, Levenson type and halftone type phase shift masks can be manufactured by the same manufacturing method as in the first embodiment.

(Simulation of Manufacturing Yield) FIG. 7 is a graph showing the relationship between the manufacturing method of the phase shift mask blanks according to the embodiment of the present invention and the conventional manufacturing method. The inventor of the present application calculated by simulation how much the manufacturing yield is improved by using the method for manufacturing a blank for a phase shift mask according to the first or second embodiment as compared with the conventional manufacturing method. .

The horizontal axis of FIG. 7 is the yield according to the conventional manufacturing method, and the vertical axis is the yield according to the manufacturing method of the present embodiment. As shown in FIG. 7, for example, the conventional manufacturing yield is 20%. In the case of 40% and 60%, 35% and 6%, respectively, by using the manufacturing method of the embodiment of the present invention.
4% and 85%, which indicates that a yield improvement of about 1.4 to 1.8 can be expected as compared with the conventional manufacturing method.

As described above, according to the first and second embodiments,
Although the details of the present invention have been described, the scope of the present invention is not limited to the examples specifically shown in the above embodiments,
Modifications of the above-described embodiment that do not depart from the scope of the present invention are included in the scope of the present invention. For example, the first and second
In this embodiment of has been described by way of SOG film as shifter film, or the like may be used sputtered SiO ₂ film and CVD SiO ₂ film. In addition, although the method of manufacturing the Levenson-type and halftone-type phase shift mask blanks has been mainly exemplified, the present invention is not limited to these types, and may be applied to any type of phase shift mask blanks. .

(Supplementary Note 1) The first substrate is placed on one surface of the transparent substrate.
Forming a second shifter film on the other surface of the transparent substrate, and forming at least one of the first shifter film and the second shifter film. Performing a defect inspection, and forming a light-shielding film on a side of the first shifter film and the second shifter film that satisfies a predetermined standard based on a result of the defect inspection. A method for producing a blank for a phase shift mask, comprising:

(Supplementary Note 2) The first substrate is placed on one surface of the transparent substrate.
Forming a shifter film, a step of performing a defect inspection of the first shifter film, and a step of forming a light-shielding film on the first shifter film when the defect inspection satisfies a predetermined standard. The second shifter film is formed on the other surface of the transparent substrate, a defect inspection of the second shifter film is performed, and the defect inspection satisfies the predetermined standard. Forming a light-shielding film on the second shifter film.

(Supplementary note 3) The method for producing a blank for a phase shift mask according to Supplementary note 1 or 2, wherein the transmittance of the light-shielding film is 0% to 30%. (Appendix 4)
A step of preparing the phase shift blanks manufactured by the manufacturing method according to any one of Supplementary notes 1 to 3,
Patterning the light-shielding film and the shifter film of the phase shift blank into a predetermined pattern.

(Supplementary Note 5) A transparent substrate, a first shifter film formed on one surface of the transparent substrate, a second shifter film formed on the other surface of the transparent substrate, 1
And a light-shielding film formed on any one of the shifter film and the second shifter film.

(Supplementary Note 6) The blank for a phase shift mask according to Supplementary Note 5, wherein the transmittance of the light-shielding film is 0% to 30%. (Supplementary Note 7) A transparent substrate and a first pattern formed on one surface of the transparent substrate in a predetermined pattern.
A light-shielding film formed by patterning a predetermined pattern on the pattern of the first shifter film;
A second shifter film formed on the other surface of the transparent substrate.

(Supplementary Note 8) A step of forming a light-shielding film on the one of the first shifter film and the second shifter film that satisfies a criterion, or the predetermined criterion in the defect inspection. If it satisfies, the step of forming a light-shielding film on the second shifter film includes not forming the light-shielding film if the result of the defect inspection does not satisfy a predetermined criterion. 4. The method for producing a blank for a phase shift mask according to any one of the above items 3.

[0055]

As described above, according to the present invention,
A first shifter film and a second shifter film are formed on one surface and the other surface of the transparent substrate, respectively, and a defect inspection of the first shifter film formed on one surface of the transparent substrate is performed. If the inspection result satisfies a predetermined standard, a light-shielding film is formed on the first shifter film.

On the other hand, if the inspection result does not satisfy the predetermined criterion, a defect inspection of the second shifter film formed on the other surface of the transparent substrate is performed. A light shielding film is formed on the shifter film. Alternatively, the first shifter film is formed only on one surface of the transparent substrate, and if the defect inspection result of the first shifter film does not satisfy a predetermined criterion, the second shifter film is formed on the other surface of the transparent substrate. A method for forming a film may be used.

By doing so, even if a defect occurs in the first shifter film formed on one surface of the transparent substrate and the defect inspection result does not satisfy a predetermined standard, the transparent substrate is not damaged. The second shifter film is inspected for defects. If the inspection result satisfies a predetermined criterion, a light-shielding film is formed on the second shifter film, and a blank for the phase shift mask is formed. Can be manufactured.

As a result, the defective rate of the transparent substrate having the shifter film can be reduced, and the production yield of the phase shift mask blank can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a method for manufacturing a blank for a phase shift mask according to a first embodiment of the present invention.

FIG. 2 is a process flowchart for explaining a method of manufacturing the blank for a phase shift mask shown in FIG. 1;

FIGS. 3A to 3D are schematic cross-sectional views illustrating a method for manufacturing a Levenson-type phase shift mask.

FIGS. 4A to 4C are schematic sectional views showing a method for manufacturing a halftone type phase shift mask according to the first embodiment of the present invention.

FIG. 5 is a schematic cross-sectional view illustrating a method for manufacturing a blank for a phase shift mask according to a second embodiment of the present invention.

FIG. 6 is a process flowchart for explaining a method of manufacturing the phase shift mask blank shown in FIG. 5;

FIG. 7 is a graph showing a yield relationship between a method for manufacturing a phase shift mask blank according to the embodiment of the present invention and a conventional manufacturing method.

[Explanation of symbols]

10, 10a: glass substrate (transparent substrate) 12, 12a, 12b, 12c: first SOG film (first
14, 14a, 14b, 14c: second SOG film (second shift film)
14d, 14e: second SOG film pattern 16: Cr film (light shielding film) 16b: Cr film pattern 18, 18a, 18b: resist film pattern 20: defect 30, 30a, 30b, 30c: phase shift mask Blanks 40, 40a: phase shift mask

Claims (5)

[Claims] A step of forming a first shifter film on one surface of the transparent substrate; a step of forming a second shifter film on the other surface of the transparent substrate; and the first shifter film Performing a defect inspection of at least one shifter film of the second shifter film; and determining a predetermined reference of the first shifter film and the second shifter film based on a result of the defect inspection. Forming a light-shielding film on the fill-side shifter film. A step of forming a first shifter film on one surface of the transparent substrate; a step of performing a defect inspection of the first shifter film; Forming a light-shielding film on the first shifter film or, if the predetermined criterion is not satisfied, forming a second shifter film on the other surface of the transparent substrate; Forming a light-shielding film on the second shifter film if the defect inspection satisfies the predetermined criterion. 3. The method according to claim 1, wherein the light-shielding film has a transmittance of 0% to 30%. 4. A step of preparing the phase shift blanks manufactured by the manufacturing method according to claim 1, wherein the light shielding film and the shifter film of the phase shift blanks are predetermined. And a step of patterning into a pattern. 5. A transparent substrate; a first shifter film formed on one surface of the transparent substrate; a second shifter film formed on the other surface of the transparent substrate; And a light-shielding film formed on any one of the shifter film and the second shifter film.