JPH0419704B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a pattern-like thick film, and specifically relates to a method for forming a pattern-like thick film with a thickness of 5 μm or more by a vacuum evaporation method, a sputtering method, etc. It is.

Figure 1 shows the first method of forming a conventional patterned thick film.
FIG. 3 is a cross-sectional view for explaining an example. A patterned thick film 5 is formed on the substrate 1 through a metal mask 2 by vacuum evaporation or the like. In this method, the substrate 1 and the metal mask 2 are brought into close contact using various jigs, but the adhesion is poor due to warping or waviness of the metal mask 2 or the substrate 1.
A gap 3 is created in between. Particles flying onto the substrate 1 from the evaporation source have various incident angles, so the evaporation material also enters the gap 3 between the metal mask 2 and the substrate 1, resulting in a pattern as shown in FIG. 1b. The pattern width becomes wider and it is difficult to control the pattern width.

FIG. 2 is a sectional view for explaining a second example of the conventional method. A photoresist is applied to the surface of the thick film 4 deposited on the entire surface of the substrate 1 by a vacuum evaporation method, exposed and developed to form a photoresist pattern 6 (a), and then the thick film is etched with a predetermined etching solution. 4 is etched to form a predetermined pattern (b)(c). In this method, side etching of the thick film 5 occurs as shown in FIG. 2b. In principle, the amount of side etching is approximately the same as the film thickness, so as the film thickness increases, the amount of side etching also increases, making it difficult to realize fine patterns. There are etching methods that cause less side etching, such as plasma etching, but they have the disadvantage that etching takes a long time if the film is thick.

As an example of the third conventional method, a lift-off method as shown in FIG. 3 can be considered. However, when a thick film 4 is formed on the surface of the lift-off layer 7 formed as shown in FIG. 3a, the edge 8 of the photoresist pattern also becomes thicker as shown in FIG. 3b. c.
As shown in FIG. 2, there is a problem in that damage or burrs occur at the edges of the thick film 5 when the film-like photoresist 7 is removed.

In order to solve these drawbacks, the present invention provides a plurality of negative type film photoresists having openings of different sizes at approximately the same center position on a substrate, and the surface of the top layer film photoresist and A thick film is deposited on the substrate through the opening, and the plurality of film-like photoresists are removed, and at the same time, the thick film on the surface of the uppermost film-like photoresist is removed to form a patterned substrate with high precision. The present invention provides a method for forming a patterned thick film. Here, in the present invention, a very thick (for example, 50 μm) film-like photoresist is used, but by using a negative type photoresist, the reaction mechanism is a polymerization reaction, and a chain reaction occurs in the thickness direction. Uniform exposure is possible without irradiating a large amount of light in any direction. On the other hand, in the method using a positive type photoresist, in order to perform exposure, reactions such as releasing C-OH groups from the photoresist material are carried out over the entire thickness of 50 μm. Since it is difficult to irradiate a sufficient amount of light uniformly in the thickness direction, there is a problem that a desired resist pattern cannot be obtained. In view of the above points, the present invention makes it possible to form a thick film pattern with high productivity and high reliability by employing a negative type film photoresist. Furthermore, the present invention uses a plurality of negative type film photoresists, and after exposing and developing the first layer photoresist, the second layer photoresist formed thereon is exposed and developed. This invention makes it possible for the first time to form a predetermined overhang in a thick film photoresist, thereby realizing the formation of a fine thick film metal wiring pattern.

The present invention will be explained in detail below. Note that the film photoresist used is a negative type resist.

FIG. 4 shows a first embodiment of the present invention, in which 1 is a substrate, 4 and 5 are thick films, and 9 and 10 are film photoresists. The manufacturing process will be explained step by step below.

(1) As shown in FIG. 4a, a first layer of film-like photoresist 9 is placed on a substrate 1 (for example, a Si wafer on which diffusion, wiring, etc. have been completed and necessary underlying metal patterns have been formed in predetermined areas). Laminated. As a negative type film-like photoresist, for example, Riston (trade name) manufactured by Dupont Co., Ltd. having a thickness of 50 μm can be used.

(2) As shown in FIG. 4b, the film-like photoresist 9 is exposed and developed to form an opening.

(3) As shown in FIG. 4c, a second layer film photoresist 10 is laminated on the surface of the first layer film photoresist 9 provided with an opening. The second layer film photoresist 10 can also be the same as the first layer film photoresist 9.

(4) As shown in FIG. 4d, the second layer film photoresist 10 is exposed and developed to form an opening with a smaller size at approximately the same center position as the opening in the first layer film photoresist 9. do.

(5) As shown in FIG. 4e, a thick film 4 is deposited on the surface of the second layer film photoresist 10. At this time, a patterned thick film 5 is also formed on the substrate 1 through the openings of the film photoresists 9 and 10. For example, Pb is used as the thick film 5,
Electron beam evaporation is used as the deposition method.

(6) Peel off the film photoresists 9 and 10 by immersing them in a stripping solution. At this time, the thick film 4 on the surface of the film-like photoresist is also removed, leaving only the pattern-like thick film 5 on the substrate, forming a desired pattern, as shown in FIG. 4f.
As the stripping liquid, acetone, methylene chloride, etc. can be used when Liston is used as the film photoresist.

Since a patterned thick film is formed through such a process, its width is defined by the opening size of the first layer film photoresist 9 and the opening size of the second layer film photoresist 10. The opening size of the second layer film photoresist 10 is determined by the thickness of the photoresist 9, and the minimum opening size when the thickness is 50 μm is about 60 μm. It is sufficient that the opening size of the first layer film photoresist 9 is about 1.2 times the opening size of the second layer film photoresist 10. Further, the thickness of the patterned thick film 5 is determined by the thickness of the first layer film photoresist 9, and can be made as thick as about 0.8 times the resist film thickness. Therefore, in the present invention, if the thickness of the first layer film-like photoresist 9 is set to 50 μm, for example, it is possible to easily obtain a pattern-like thick film that is unprecedentedly thick and narrow, with a width of about 70 μm and a thickness of about 40 μm. I can do it.

Next, a second embodiment of the present invention is shown in FIG. First layer film photoresist 9 and second layer film photoresist 1 in the first embodiment
A first layer of film-like photoresist 9 is placed in the middle of 0.
A film-like photoresist 11 having an opening of the same size and at approximately the same center position is provided. The rest is the same as the first embodiment. Since the first layer film photoresist 9 has a sufficiently thick structure, it is possible to form a thicker patterned film with the same pattern width as in the first embodiment. It goes without saying that by increasing the number of layers of the film-like photoresist 10, it is possible to form an even thicker pattern-like thick film. It is also natural that the same effect can be obtained by using a thick film photoresist for the first layer without increasing the number of layers.

Further, a third embodiment is shown in FIG. The film-like photoresists 10 and 12 have openings having substantially the same size at substantially the same center position, and the intermediate layer film-like photoresist 11 has an opening slightly larger than the film-like photoresists 10 and 12. The rest is the same as the first and second embodiments. Because of this structure, even when deposits enter beyond the opening size of the film photoresist 10, the pattern size is defined by the opening size of the film photoresist 12, and the first and second
It is possible to obtain a patterned thick film with more accurate dimensions than in the embodiment. In addition, if a film photoresist having an opening of the same size as the film photoresist 10 is stacked on the film photoresist 10 in FIG. 6, or if a sufficiently thick film photoresist 10 is used, the substrate 1 The angle of incidence of the deposited material on the film becomes small, and a patterned thick film with high dimensional accuracy can be obtained more easily.

In the example shown here, Si was used for the substrate, but it may also be made of glass, ceramic, metal, etc., and although Pb was used for the deposited film, it may be made of other metals, insulators, etc. The deposition method is not limited to the vacuum deposition method, but a sputtering method or the like may also be used.

As explained above, the present invention has multiple layers of thick negative-type film-like photoresist, and the opening dimensions of the film-like photoresist in each layer are changed, so there is no damage or burrs on the edges, and there is little or no spreading. This method has the advantage that a patterned thick film without any blemishes can be easily obtained.

The present invention is extremely effective in reducing conductor resistance and realizing high-density terminal connections when applied to wiring and electrode formation in the manufacture of integrated circuits, hybrid integrated circuits, and the like.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view for explaining a conventional method for forming a patterned thick film using a metal mask, Figure 2 is a cross-sectional view for explaining a conventional method for forming a patterned thick film by etching, and Figure 3. Figure 4 is a cross-sectional view for explaining the conventional pattern-like thick film formation method using the lift-off method using one layer of photoresist, and Figure 4 is a cross-sectional view for explaining the conventional pattern-like thick film formation method using the lift-off method using a single layer of photoresist. FIG. 5 is a cross-sectional view for explaining the pattern-like thick film forming method according to the present invention.
A cross-sectional view for explaining the pattern-like thick film forming method according to the present invention in which a negative type film-like photoresist having an opening of the same size as the layer is added to form three layers, and FIG. 6 is a formation related to FIG. 4. FIG. 3 is a cross-sectional view for explaining a method for forming a patterned thick film of a three-layer resist structure in which the opening of the second layer of film-like photoresist is slightly enlarged using the method. 1... Substrate, 2... Metal mask, 3... Gap, 4, 5... Thick film, 6, 7... Photoresist, 8... Edge, 9, 10, 11, 12... Negative type film photoresist.

Claims (1)

[Claims] 1. After a thick film is deposited on the surface of a substrate on which a film-like photoresist having a predetermined opening pattern is formed, the film-like photoresist and the thick film deposited on the surface are removed. In the method for forming a pattern-like thick film on the substrate, the film-like photoresist is formed by stacking a plurality of negative-type film-like photoresists, and the openings of each film-like photoresist are arranged in the respective film-like photoresists. so that the center positions substantially coincide with each other, and the dimensions of the opening formed in at least one film-shaped photoresist among the plurality of film-shaped photoresists are smaller than the dimensions of the opening formed in the other film-shaped photoresists. When forming a negative type film photoresist, a negative type first layer film photoresist is laminated on the substrate, exposed and developed to form the opening, and a negative type second layer film photoresist is formed on the surface of the first layer film photoresist. Photoresists are laminated, exposed and developed to form an opening smaller than the opening size of the first layer photoresist at approximately the same center position as the opening of the first layer photoresist, and the surface of the second layer film photoresist and A pattern characterized in that a thick film is deposited on the substrate through both the openings, and the second layer film photoresist and the first layer film photoresist are removed together with the thick film on the surface of the second layer film photoresist. Method for forming thick film. 2. The method of forming a patterned thick film according to claim 1, wherein the first layer film photoresist is thicker than the second layer film photoresist. 3. After a thick film is deposited on the surface of a substrate on which a film-like photoresist having a predetermined opening pattern is formed, the film-like photoresist and the thick film deposited on the surface are removed. In the method for forming a patterned thick film on a film, the film-like photoresist is formed by stacking a plurality of negative-type film-like photoresists, and the center positions of the openings of each film-like photoresist are substantially coincident with each other. and when forming the opening in at least one of the plurality of film-like photoresists so that the size of the opening formed in the other film-like photoresist is smaller than the size of the opening formed in the other film-like photoresist, A negative type first layer film photoresist is laminated on the substrate, exposed and developed to form the opening, and a negative type second layer film photoresist is laminated on the surface of the first layer film photoresist and exposed.・Develop to form an opening larger than the opening size of the first layer photoresist at approximately the same center position as the opening of the first layer photoresist, and laminate a negative type third layer film photoresist on the surface of the second layer. Then, it is exposed and developed to form an opening with approximately the same dimensions as the first layer at approximately the same center position as the opening in the first layer, and the surface of the third layer, the third layer, the second layer, and the first layer. Formation of a patterned thick film, characterized in that a thick film is deposited on the substrate through the opening, and the film-like photoresists of the third layer, the second layer, and the first layer are removed together with the thick film on the surface of the third layer. Method.