JPH022558A - Correcting method for mask pattern - Google Patents

Abstract

PURPOSE:To remove a suspended chromium film from on a protection film entirely without forming any step at the absence part of a mask by forming the protection film which is not peeled off in a lift-off process between a substrate and resist by coating. CONSTITUTION:The protection film 7 and photoresist film 5 are adhered in order on a substrate 2 where a light shielding film pattern 1 is formed while covering the light shielding film pattern 1, the photoresist film 5 on a pinhole 5 is exposed in a spot, and development is carried out to form an opening on the pinhole 3. The photoresist is used as the mask to etch the protection film 7 on the pinhole 3 and a light shielding film 6 for correction is adhered over the entire surface of the substrate 2 while covering the opening; and the photoresist film 5 and light shielding film 6 for correction are lifted off and removed, then the protection film 7 is peeled off, and the light shielding film 6P for correction is adhered in the pinhole 3. Consequently, when the white defect of the mask is corrected, such a secondary defect that the residues of the light shielding film 6 used for the correction stick on the absent part of the light shielding film pattern 1 is prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] This invention relates to a pattern correction method for masks and reticles used in the manufacture of ICs and the like.

The purpose of this method is to prevent the correction light-shielding film from adhering to the blank areas of the light-shielding film pattern when correcting white defects on the mask.

A protective film and a photoresist film are sequentially deposited on a substrate on which a light-shielding film pattern is formed, covering the light-shielding film pattern, and the photoresist film on the pinholes formed in the light-shielding film pattern is spot-exposed. Then, the photoresist film is developed to open an opening above the pinhole. Then, using the opened photoresist as a mask, the protective film over the pinhole is etched to open it, and the opening is covered with a substrate. A process of depositing a light-shielding film for correction on the entire surface, peeling off the photoresist film, lifting off and removing the light-shielding film for correction on the photoresist film, and then peeling off the protective film, The correction light-shielding film is configured to be deposited within the upper pinhole.

[Industrial application field]

The present invention relates to a method for modifying patterns of masks and reticles used in the manufacture of integrated circuits (ICs) and the like.

[Conventional technology]

In conventional pattern correction techniques, white defects (pinholes, chips) have been corrected using a zero-order lift-off technique as shown in FIG.

FIGS. 2(11-5) are cross-sectional views of a mask illustrating a conventional mask pattern correction method.

In FIG. 2 (11), a chrome pattern 1 is formed as a light-shielding film pattern on a substrate 2. 3 indicates a pinhole that is to be corrected in the chrome pattern 1;
4 is the part where the light-shielding film pattern is removed.

That is, it is a light-transmitting part of the mask.

In Figure 2 (2), photoresist 5 is applied over the entire surface of the substrate.
is applied, and spot exposure is performed on the pinhole 3 with ultraviolet (UV) light.

In FIG. 2(3), the photoresist 5 is developed to open above the pinhole 3. In FIG.

In FIG. 2(4), repair chromium films 6 and 6P are deposited on the entire surface of the substrate by sputtering.

Here, the correction chromium film 6 is on the photoresist.

The correction chromium film 6P is deposited on the pinhole 3.

In FIG. 2(5), the photoresist 5 is peeled off using a stripping solution, and the repair chromium film 6 is lifted off and removed.

As described above, the pinhole 3 opened in the light-shielding film of the mask is corrected with the correction chromium film 6P.

[Problem to be solved by the invention]

In the above conventional technology, as shown in FIG.
When the repair chromium film 6 is lifted off together with the photoresist 5, the floating residue 6F of the repair chrome film 6 may adhere to the cutout portion 4 of the light shielding film.

An object of the present invention is to prevent the occurrence of secondary defects in which a light-shielding film for repair adheres to the punched portions of a light-shielding film pattern when a white defect on a mask is repaired.

[Means to solve the problem]

The above problem can be solved by sequentially depositing a protective film and a photoresist film on a substrate on which a light-shielding film pattern is formed, covering the light-shielding film pattern.
The photoresist film on the pinhole is spot exposed (1), the photoresist film is developed and an opening is made over the pinhole (1), and the exposed photoresist is used as a mask to protect the vinylhole. The film was etched to open an opening, a correction light-shielding film was applied to the entire surface of the substrate covering the opening, the photoresist film was peeled off, and the correction light-shielding film on the photoresist film was lifted off and removed. rear.

This is achieved by a mask pattern modification method that includes a step of peeling off a protective film, and in which the modification light-shielding film is deposited within the pinhole on the substrate.

[Effect]

In order to prevent the floating chromium film from adhering to the exposed portion of the light-shielding film when lifting off the correction chromium film on the resist, the present invention provides protection between the substrate and the resist so that it will not be peeled off during lift-off. This method takes advantage of the fact that if the film is applied, there will be no step difference in the area where the mask is removed, so the floating chromium film can be removed cleanly from the top of the protective film.

〔Example〕

FIGS. 1(1) to 1(5) are cross-sectional views of a mask illustrating a method of correcting a mask pattern according to an embodiment of the present invention.

In FIG. 1 (1), an EB resist (EBI?-9 manufactured by Toshisha Co., Ltd.) with a thickness of 0.3 μm is used as a protective film 7 on a substrate 2 on which a chromium pattern 1 is formed as a light-shielding film pattern.
was applied on a real plate in the air at 200°C for 10
After applying beta for 1 minute, a photoresist l-(OFPR-800 manufactured by Tokyo Ohka Co., Ltd.) 5 with a thickness of 0.5 μm was applied.
Beta is similarly carried out at 92°C for 2 minutes.

In the figure, reference numeral 3 indicates a pinhole that has occurred in the chrome pattern 1 and is to be corrected, and reference numeral 4 indicates a missing portion of the light-shielding film, that is, a transparent portion of the mask.

Next, the pinholes 3 of the photoresist 5 coated on the entire surface of the substrate are spot-exposed with ultraviolet light.

In FIG. 1(2), the photoresist 5 is developed by a spray method using a developer (NMD-3 manufactured by Tokyo Ohka Co., Ltd.) to open above the pinhole 3.

In FIG. 1(3), the protective film 7 is dry etched with oxygen plasma using the photoresist 5 as a mask.

Oxygen plasma dry etching is performed using a parallel plate electrode type etching apparatus under the following conditions.

Oxygen flow m: 50 SCCM, pressure: 0.1
5 Torr.

Applied power: 200 W, Frequency: 13.56
MHz.

Electrode spacing: 50 mm.

Next, repair chromium films 6 and 6P are deposited as repair light-shielding films with a thickness of 0.06 μm over the entire surface of the substrate by sputtering. Here, the correction chromium film 6 is deposited on the resist, and the correction chrome film 6P is deposited on the pinhole 3.

In FIG. 1(4), the resist 5 is peeled off using a high-pressure spray method using a 5% aqueous sodium hydroxide solution, and the correction chromium film 6 is lifted off and removed.

At this time, since the removed portion 4 of the light-shielding film pattern is flatly covered with the protective film 7 and there is no step, the correction chrome film 6 can be peeled off cleanly without leaving any residue.

In FIG. 1 (5), the protective film 7 is exposed to DtlV light (wavelength 2
After the entire surface was exposed to 80 nm deep ultraviolet light), it was stripped with 100% butyl acetate.

In the manner described above, the pinhole 3 opened in the light shielding film of the mask is corrected with the chromium film 6P.

〔Effect of the invention〕

As described above, according to the present invention, when a white defect on a mask is repaired, it is possible to prevent the occurrence of a secondary defect in which the residue of the light shielding film used for repair adheres to the punched portion of the light shielding film pattern.

[Brief explanation of the drawing]

Fig. 1 (11 to (5)) is a cross-sectional view of a mask explaining a method for correcting a mask pattern according to an embodiment of the present invention. Cross-sectional view of the mask to be explained 8 Figure 3 is a cross-sectional view to explain the problem. In the figure. 1 is the light-shielding film pattern, chrome pattern 2 is the substrate. 3 is the problem that occurred in the light-shielding film pattern. Pin to be corrected Hole. 4 is the cut-out part of the light-shielding film pattern (light-transmitting part of the mask). 5 is the photoresist 6 is the light-shielding film for correction and is a chrome film. 7 is the protective film, which is a cross-sectional view of an example of poor EB resist.

Claims (1)

[Claims] A protective film and a photoresist film are sequentially deposited on a substrate on which a light-shielding film pattern is formed, covering the light-shielding film pattern, and the photoresist film on the pinholes formed in the light-shielding film pattern is spot-exposed. The photoresist film is developed to create an opening above the pinhole, and then, using the opened photoresist as a mask, the protective film over the pinhole is etched to open it, and the substrate is covered with the opening. A process of depositing a light-shielding film for correction on the entire surface, peeling off the photoresist film, lifting off and removing the light-shielding film for correction on the photoresist film, and then peeling off the protective film, A method for correcting a mask pattern, characterized in that the correcting light-shielding film is deposited in the upper pinhole.