JPS5834921A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To improve chemichal resistance by a method wherein a far ultra violet photosensitive photoresist and a photoresist film that is opaque to far ultra violet rays are coated in order, then patterning with a visible ray is followed by patterning with far ultra violet exposure. CONSTITUTION:A negative type photoresist 3 that is photosensitive to far ultra violet rays is coated on a metal film 2 which is coated on a semiconductor substrate 1. Next, a positive type photoresist 4 that is photosensitive to a visible ray and opaque to far ultra violet rays is coated on the above surface, thereon a photomask 5 is place in contact with, then irradiation with a visible ray 6 is followed by development. The positive type photoresist layer which received the visible ray irradiation is removed to form an opening, ultra violet rays 7 is irradiated, and development is performed. Only the opening of a negative type photoresist 3, the lower layer, is exposed, then this is processed in proper etching liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a semiconductor device, and particularly to a method of forming a pattern of 7 photoresists on a semiconductor substrate.

Recently, with the progress of microfabrication technology, the frequency of use of positive photoresists has increased. The reason for this is that positive type photoresists generally have superior resolution compared to negative type 7-inch resist F, and because the photomask has a large number of black areas, it is less likely to be affected by dust and can be expected to have a high yield. be. However, since positive type photoresists generally have carbonic acid resin as their main component, they have the disadvantage of poor chemical resistance during etching, which has also been a factor in lowering yields.

The present invention provides a method that can take advantage of the high resolution of positive photoresists and prevent a decrease in yield due to chemical resistance.

In the present invention, a deep ultraviolet-sensitive negative photoresist is coated on a material to be etched on a semiconductor substrate, and further,
After applying a thin film of positive photoresist that is opaque to deep ultraviolet light and patterning the positive photoresist using visible light, using this as a mask, pattern the lower negative photoresist by exposure to deep ultraviolet light. This is a way to lend money.

According to the present invention, high-resolution patterning can be performed, and the resulting photoresist pattern has strong chemical resistance.

Next, embodiments of the present invention will be described using the drawings.

This embodiment will be described using an example in which four films are patterned on gold on a semiconductor substrate.

In FIG. 1, a metal thin film 2 is deposited on a semiconductor substrate 1. As shown in FIG. Next, a negative photoresist 3 sensitive to deep ultraviolet light is applied onto the metal film 2. Next, a positive photoresist 4 that is sensitive to visible light and opaque to deep ultraviolet light is applied, a photomask 5 is closely attached, and visible light 6 is irradiated, followed by development. After development, as shown in FIG. 2, the portions of the positive photoresist layer irradiated with visible light are removed to form openings. Next, development is performed after irradiating with far ultraviolet light 7.

Since the photoresist 4 is opaque to deep ultraviolet light,
Only the opening portions of the lower layer negative photoresist 3 are exposed, and a pattern as shown in FIG. 3 is formed.

Next, this is treated in a suitable etching solution to form a metal pattern as shown in FIG.

[Brief explanation of the drawing]

1 to 4 are cross-sectional views for explaining one embodiment of the present invention. In the plan view, '1 is the semiconductor substrate, 2 is the gold kI4 film, and 3 is the semiconductor substrate.
is negative photoresist, 4 is bo\81! A photoresist, 5 a photomask, 6 visible light, and 7 far ultraviolet light. Yasuke. To m-No J “□--No-11--ri-”-? 1 Figure / Gu? , stem ,, )′ Fig.

Claims (1)

[Claims] A step of applying a negative photoresist sensitive to deep ultraviolet region onto a material to be etched on a semiconductor substrate;
A step of applying a positive 117-oF resist that is photosensitive in the visible region and opaque to deep ultraviolet light on the photo-resist, and patterning the positive photoresist by irradiating visible light using a 7-oF mask. A method for manufacturing a semiconductor device, comprising: a step of patterning the negative type 7-oscillator resist by irradiating far ultraviolet light.