JPH01154060A - Production of photomask - Google Patents

Abstract

PURPOSE:To produce the photomask with high accuracy by applying a resist to a metallic plate, executing pre-baking, radiating an electron beam or ultraviolet rays, thereafter, bringing a chrome film to vapor-deposition and executing the development and etching. CONSTITUTION:A chrome film 2 is formed on a quartz substrate 1, an EB negative resist 3 is applied on a metallic plate, pre-baking is executed, and thereafter, an electron beam 4 or ultraviolet rays is radiated on a prescribed area. Thereafter, when a chrome film 5 is brought to vapor-deposition on the whole surface of the plate by a spattering device, and a dip development is executed, the resist 3 of an unexposed part is melted. In this case, the chrome 5 which is brought to vapor-deposition onto the resist 3 of the unexposed part is also eliminated together with the resist 3. Subsequently, when etching is executed by a dry etching device, the chrome film 2 of the part where the resist 3 is melted and the chrome film 5 which is brought to vapor-deposition onto the resist 3 of the part which is irradiated by the electron beam 4 are brought to etching, and in the end, by peeling off the resist 3, a desired mask pattern is obtained. In such a way, the photomask can be manufactured with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a photomask used in the manufacture of semiconductors and integrated circuits.

[Conventional technology]

The conventional photomask manufacturing method, as shown in the process diagram in Figure 2, first forms a chromium film 2 on a quartz substrate 1, and then coats a metal plate with chemicals such as acids and surfactants, or with a scrubber. Wash. Next, resist 3, which is a photosensitive agent, is applied and prebaked. Thereafter, unnecessary portions of the resist are removed through a development process by irradiation with an electron beam 4 or ultraviolet rays.

Then, chromium film 2 and resist 3 are formed by boss baking.
After strengthening the adhesion, etching is performed to dissolve and remove the chromium film in areas where the resist 3 cannot be removed in the development process. Finally, the remaining resist 3 is 181 processed to complete the photomask.

By the way, recently, in order to improve the accuracy of etching,
Dry etching, in which etching is performed in a plasma consisting of a mixed gas of carbon tetrachloride and oxygen, is becoming mainstream, rather than wet etching, which uses an etching solution containing ammonium cerium nitrate and perchloric acid as main components.

[Problem that the invention seeks to solve]

In the conventional photomask manufacturing method described above, when dry etching is applied to the etching process, EB resists with low dry etching resistance, such as PGMA,
With PBS, EBR-9, etc., the resist evaporates before chromium etching is completed. That is, at a practical level, it is difficult to manufacture photomasks using these resists by highly accurate dry etching.

[Means for solving problems]

In the photomask manufacturing method of the present invention, a resist is coated and prebaked on a metal plate consisting of a multilayer or single-layer thin film of chromium and chromium oxide, and after irradiation with an electron beam or ultraviolet rays, a chromium film is deposited on the entire surface of the plate. It is characterized by developing and etching.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a diagram showing the manufacturing process of the present invention. Quartz substrate 1
A chromium film 2 of approximately 1,000 layers is formed thereon. Next, apply EB negative resist 3, for example PGMA 60, to the metal plate.
Apply to a thickness of 0.00 people.

After prebaking at 80 to 100° C. for 20 to 30 minutes, a predetermined area is irradiated with an electron beam 4 using an electron beam exposure device. Thereafter, a chromium film 5 is deposited on the entire surface of the plate to a thickness of about 1,000 layers using a sputtering device. Next, when dip development is performed, the unexposed portions of the resist 3 are dissolved. At this time, the chromium 5 deposited on the unexposed portions of the resist 3 is also removed together with the resist 3. Next, etching was carried out using a dry etching device for the time required to etch the chromium film of 1,000 people, and the chromium film 2 was vapor-deposited on the chromium film 2 where the resist had melted and the resist 3 where the electron beam 4 had been irradiated. The chromium film 5 is etched.

Finally, the desired mask pattern is obtained by peeling off the resist 3.

Note that in the above embodiments, a quartz substrate is used, but a glass substrate may also be used. The chromium film is a multilayer or single-layer thin film of chromium and chromium oxide, and the exposure may be ultraviolet light.

〔Effect of the invention〕

As explained above, if the photomask manufacturing method according to the present invention is used, a pattern can be formed by dry etching even if a resist without dry etching resistance is used, and a highly accurate photomask can be manufactured.

[Brief explanation of the drawing]

FIG. 1 is a process diagram of the photomask manufacturing method of the present invention, and FIG.
The figure is a process diagram of a conventional photomask manufacturing method. DESCRIPTION OF SYMBOLS 1...Quartz substrate, 2...Chromium film, 3...Resist, 4...Electron beam, 5...Chromium film.

Claims (1)

[Claims] A metal plate consisting of a multilayer or single-layer thin film of chromium and chromium oxide is coated with a resist and prebaked, and after irradiation with an electron beam or ultraviolet rays, a chromium film is deposited on the entire surface of the plate, and then developed and etched. Method of manufacturing a photomask.