JPS58101427A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To form a resist pattern with minute opening dimension by a method wherein two sides constituting angle of opening are formed by two different kinds of photomask. CONSTITUTION:A conductive pattern 2 on Si substrate 1 is covered with SiO23 and positive type exposing resin 4 and radiated from ultraviolet ray X using a mask in case of forming the pattern 2 to make exposure region 4. Said pattern 2 is radiated from another ultraviolet ray Y adjusting the amount radiated so that the region 5 radiated from the ultraviolet rays X, Y may be resolved into developer in the thickness direction. After the development, the region 5 is completely removed to form an opening 6 exposing the SiO2 film 3. Said film 3 is etched utilizing residual resin as a mask to expose the conductive layer 2 forming a conductive layer pattern 7'. Through these constitution, minute rectangular port with small opening dimension may be formed enabling to manufacture a semiconductor device with high density.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for forming fine and accurate openings in the manufacturing process of semiconductor devices.

In the manufacturing process of semiconductor devices, a method of forming openings in a film to be etched is, for example, by forming a photosensitive resin film on the film to be etched in one step, and using a photomask having a predetermined pattern of holes. A pattern is formed on the photosensitive resin film by selectively irradiating it with ultraviolet rays and performing development and fixing processes. Thereafter, a predetermined pattern of holes is formed in the film to be etched, such as an insulating thin film, by a normal etching method.

In this method, when the dimensions of the aperture pattern become smaller, the corners of the rectangular or square photomask and resist aperture patterns become rounded, the fine square patterns become circular, and in extreme cases, the apertures become distorted due to light diffraction and diffuse reflection. The disadvantage is that a pattern cannot be formed.

The present invention has been made to improve the above-mentioned drawbacks, and the present invention is exemplified by forming an opening for connecting a first conductor layer and a second conductor layer arranged through an insulating film. Let me explain.

An embodiment of the present invention will be explained based on FIG. A conductive layer pattern 2 made of a first conductive layer is formed on the semiconductor substrate 1.
is formed, and further a substrate 1. An insulating film 3 is formed on the pattern 2. A positive photosensitive resin 4 is formed on a film to be etched, such as an insulating film 3 (step 3). Note that an insulating film (not shown) may be formed on the surface of the substrate 1, and a pattern 2 made of polycrystalline silicon or the like may be formed thereon. Next, the photosensitive resin film 4 is selectively irradiated with the first ultraviolet ray I using the photomask or reticle (hereinafter abbreviated as the photomask of the tube 1) used when the first conductor layer pattern 2 was formed. 4'' is a second photomask that intersects the first photomask and has a pattern width wider than the width of the opening of the connection portion in a direction different from that of the first photomask at a continuation portion that is an ultraviolet irradiation area; to selectively irradiate the photosensitive resin film 4 with the second ultraviolet rays Y (C1° first and second
The irradiation amount of ultraviolet rays is such that the photosensitive resin film only at the intersection of the first and second photomasks, that is, the area 6 irradiated with both the first and second ultraviolet rays, is completely covered in the thickness direction. The energy is such that it becomes soluble in the developer. 6′ is! This is the only part that was irradiated.

Next, UV X is applied through normal development and rinsing.

When the photosensitive resin in the irradiated area of Y is removed, the photosensitive resin film (part 6) at the intersection is completely removed to form an opening 6, exposing a part of the insulating film 3 ( D.J.

Using the remaining photosensitive resin film as an etching mask, the exposed insulating film 3 is etched to expose the conductive layer 2.

Thereafter, a conductive layer 7 is formed on the entire surface, and then the openings 6 are etched using the second photomask and a negative type photosensitive resin film by ordinary photolithography.
A pattern 7' consisting of the conductor layer 7 connected to the conductor layer 2 is formed (Fl).

In the above embodiments, the first photomask may be a photomask having a second conductor layer pattern or another photomask that intersects the first conductor layer at the connection portion between the first conductor layer and the second conductor layer. A photomask having a pattern may be used, and a photomask having a first conductor layer pattern may be used as the second photomask.

It goes without saying that a positive photosensitive resin film may be used to form the conductor layer pattern 7' using a photomask having a black and white pattern inverted from that of the second photomask. Furthermore, after irradiation with ultraviolet X in the step of FIG. 1 (Bl), a normal development and rinsing treatment may be performed to form a film thickness difference in the photosensitive resin film, and then a second ultraviolet treatment may be performed.

According to the above method, FIG. 1 (Bl) and FIG. 2 (M)
As is clear from FIG.
cl and FIG. 2 (Bl), when the ultraviolet irradiation part 6' is formed using the photomask pattern for forming the second conductor layer, an opening 6 is formed at the intersection 6 of the irradiation parts 3' and 5'.
Therefore, there is no need for a photomask for forming the opening, and the number of useless photomasks for manufacturing semiconductor devices can be reduced by one.

Furthermore, in the methods shown in FIGS. 1 and 2, the two sides forming the corners of the opening are formed by two different types of photomask patterns. Therefore, even if the size of the opening becomes smaller, the corners of the photomask pattern do not become rounded as in the conventional case, and a fine rectangular pattern can be formed on the photosensitive resin film.

As described above, according to the present invention, in microfabrication, for example, the two sides forming the corners of the opening are formed using two different types of photomask patterns.

Therefore, it is possible to form a fine resist pattern even if the size of the opening becomes small, which greatly contributes to the manufacture of high-density semiconductor devices.

[Brief explanation of the drawing]

Figures 1 (m) to 1 are process cross-sectional views for explaining the method of one embodiment of the present invention, Figure 2 (m) is a schematic plan view corresponding to Figure 1 +e+, and Figure 2 fBl is FIG. 1 is a schematic plan view corresponding to FIG. DESCRIPTION OF SYMBOLS 1... Semiconductor substrate, 2... First conductor layer pattern, 4... Photosensitive resin film, 5...
...Irradiation area, 6...Opening part, 7'...
・Conductor layer pattern. Name of agent: Patent attorney Toshio Nakao and 1 other person27
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Claims (3)

[Claims] (1) A photosensitive resin film formed on an insulating film to be etched, and at least one wiring layer connected to each other via the film to be etched by openings formed in the film to be etched. After overlapping exposure using a first mask having a pattern and a second mask having another pattern that intersects the pattern,
The photosensitive resin film at the intersections of the wiring layer pattern is removed by performing a predetermined development and rinsing process, and the exposed film to be etched is selectively etched to form the opening. A method for manufacturing a semiconductor device. (2) First. 2. The method of manufacturing a semiconductor device according to claim 1, wherein the second mask is a mask for forming a wiring layer pattern connected via an etched film. (3) The intersection of the photosensitive resin is the first. 2. The method of manufacturing a semiconductor device according to claim 1, wherein the semiconductor device is completely exposed in the thickness direction using the second mask.