JPS5898931A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To form a minute pattern readily, by forming a resist pattern on a heat resisting resin layer on a substrate by dry development, thereafter performing etching, thereby making all the processes dry. CONSTITUTION:A thin metal film 2 is formed on the glass substrate 1, and a polyimide resin is applied thereon as the heat resisting resin layer 6. Then an SiO2 thin film 7 is formed. A resist 3 is further applied. Then, with the resist pattern 4 as a mask, the SiO2 thin film 7 is etched. Thereafter, with a pattern 10 of the thin film 7 as a mask, the resin 6 is etched in the plasma in O2 gas. In this method, the pattern, which is very sharp and has a very large aspect ratio, can be obtained. Therefore, the etching of the thin chromium film 2 can be performed readily, and the sharp edges can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a semiconductor device that includes a step of etching a resist film formed on a substrate.

When manufacturing semiconductor devices such as integrated circuits, photolithography technology is generally used to form patterns. ,Automation,
Technological development for labor-saving and other purposes has become active9, and attempts to apply dry technology to the entire phosphorography process are effective in reducing defects, automation, and labor-saving, and research and development are being carried out in various fields. It's coming. For example, in the mask manufacturing process, while dry etching has been put into practical use in the etching process, solution development is still widely used in the developing process, and drying in all processes has not yet been put into practical use. is the current situation.

Hereinafter, a conventional mask manufacturing method will be explained with reference to FIG.

First, as shown in Fig. 1 (4), K, the glass substrate (1)
A thin metal film, such as a metal chromium thin film (9) is deposited, and then a film (3) for electron beam use is deposited to a thickness of about 5,000 mm. Deposit and pre-bake at 170°C for 20 minutes, then apply an electron beam to a 9X1
Irradiation is performed at a dose of 0 c/d in accordance with the desired pattern. Furthermore, methyl isobutyl ketone (MIBK)
Prepare a solution of Improper Tool (HF) at a ratio of 10 to (8), perform development using this solution, and
A resist pattern (4) as shown in Figure (C) is created.

Then, after rinsing and drying, the resist pattern (4) is used as a mask to form a thin metal film as shown in Figure 1 ψ). 14 (2
) is etched. After that, the desired metal thin film pattern (5) is obtained by removing the resist pattern (4) as shown in Figure 1 (dog). Generally, the resist pattern (3) for electron beam exposure has a plasma resistance, and tb decomposition. Because of its poor properties, it is treated with chemical etching, or wet etching.

As described above, development and etching in the conventional mask manufacturing method are wet processes, and the presence of foreign matter in the solution cannot be avoided, which hinders the reduction in defects. Furthermore, automation and labor saving are difficult, and there are also problems with wastewater treatment. Furthermore, wet etching has disadvantages such as a large amount of side etching, making it difficult to control dimensions and making it difficult to obtain fine patterns. The purpose of the present invention is to provide a method for manufacturing a semiconductor device in which the entire process can be made dry by forming a resist pattern on a heat-resistant resin layer using a dry image and then etching it, and in which fine patterns can also be easily formed. It is said that

Embodiments of this invention will be described below with reference to the drawings.

FIGS. 2(5) to 2(G) show the method of manufacturing a semiconductor device according to the present invention in the order of steps.

First, as shown in FIG. 2 (CA), a metal thin film, eg, metal chromium thin film 111 (2), is formed on a glass substrate (1). On top of that, a heat-resistant resin layer (6) is made of polyimide resin, such as electrically insulating coating agent 5P510 (
Apply Toshisha Co., Ltd. (trade name) to a thickness of about 6,000 people. After coating this, baking is performed in a nitrogen atmosphere at approximately 80°C for 30 minutes, and then a silicon oxide thin film (8i0*
) (7) is formed to a thickness of approximately 800 mm by plasma deposition. Furthermore, as a resist (3), IFMR (
Fuji Yakuhin Co., Ltd. (trade name) was applied to a thickness of about 5,000 people, and baked at about 140° C. for 30 minutes in a nitrogen atmosphere.

-)i! 'K, resist as shown in Figure 2gQK (3)
A desired pattern is formed by selectively irradiating the K electron beam. The dose of the electron beam is 6X1G-'c/d. After electron beam irradiation, the unevenness of the patterned portion of the irradiated area was measured using a surface roughness needle, and approximately 600 concave steps were observed. Next, develop this material in plasma.The development conditions are wet air I Torr and output cap 0W.
The development was completed in about 60 minutes. '! When the film thickness of the resist pattern (4) after the II image was measured with a surface roughness needle, a convex pattern (4) of about 2000 was obtained (FIG. 2(C)). This resist pattern (4) was used as a mask, and 8i0.
When the thin film (7) was etched as shown in FIG. 2(D), the etching was completed in about 10 minutes.

Next, using the OS i Os (7) pattern & (I as a mask, heat-resistant resin (6) is
etched. Etching was performed using plasma in Os gas at an output of 300 W. The nine patterns obtained in this way are very sharp and have an extremely large aspect ratio.
') Etching of chromium thin film 111 (2) shown in K shows a sharp edge can be easily obtained.
-2 TorrOccls gas. lastly,
Heat-resistant resin (6) and 8i0. If pattern (7) is removed, the chrome pattern shown in FIG. 2(G) is obtained.

According to the above method, in the mask manufacturing process,
There is no need for wet processing, and everything can be done dry, with the promise of fewer defects, labor savings, automation, and fine patterning.

Further, it is now possible to easily dry-etch the electron beam resist, which has hitherto been impossible to dry-etch, and the dimensional accuracy can be improved. Furthermore, the obtained resist layer is coated with heat-resistant resin (6) as shown in Figure 2 (D).
Since it has a high aspect ratio, dry etching, which is impossible with conventional wafer processes, can be easily introduced.

In addition, in the above embodiment, a chromium thin film 11 (2
), however, other materials may be used, and the substrate (1) may also be other than a glass substrate.

Further, in the above embodiments, FMR was used as the resist (3), but other resists having a high residual film ratio can also produce similar effects. Furthermore, although an electron beam has been described as an example of radiation, similar effects can be achieved with X-rays or ion beams. As the heat-resistant resin layer (6), BP510 is taken as an example.
(manufactured by Dv Font Co., Ltd.: trade name), H Aero 00 (manufactured by Hitachi Chemical Co., Ltd.: trade name), etc. have similar effects.

In order to form a predetermined pattern on a metal thin film on a substrate, this invention includes a heat-resistant resin layer on the metal thin film,
After sequentially forming a silicon oxide thin film and a resist,
By forming the resist pattern using a dry pattern and then etching it, the entire process can be made dry.
This has the effect of increasing reliability and making it easier to form fine patterns.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a conventional method for manufacturing a semiconductor device in order of steps, and FIG. 2 is a cross-sectional view showing a method for manufacturing a semiconductor device according to an embodiment of the present invention in order of steps. (1)...Substrate, (2)...Metal thin film, (3)...
-Resist for electron beam exposure, (4)...Resist pattern, (5)...Desired metal thin film pattern, (6)
...Heat-resistant resin layer, (7)...Silicon oxide thin film. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Makoto Kuzuno (1 other person) Figure 1 Figure 2 Procedural amendment (fl) 1'>+i'l'Ii' b Government building 1, ・It fi indication Patent application 1987-1991
85 No. 2゜ Title of the invention Method for manufacturing a semiconductor device 3 Relationship with the case of the person making the amendment Patent applicant 6゜ Subject of amendment (1) The description is amended as follows.

Claims (1)

[Claims] (1) To form a predetermined pattern on a round metal thin film formed on a substrate, a heat-resistant resin layer and a silicon oxide thin film are sequentially formed on the metal thin film, and then a resist is applied on this silicon oxide thin film. A film is deposited, and then the resist # is selectively irradiated with radiation and the resist film is developed in plasma to form a resist F pattern, and then the silicon oxide thin film is etched using the resist pattern as a mask. A method of manufacturing a semiconductor device, further comprising etching the heat-resistant resin layer in plasma.