JPS59127897A - Method of forming thick film pattern - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a thick film pattern by photolithography, and particularly to an improvement in photolithography for forming a thick film pattern with higher precision.

In forming a thick film pattern, a thick film paste is rolled onto a substrate and then a pattern is formed on the thick film paste, but the thickness of the thick film paste is formed with a certain degree of variation. This tendency is particularly noticeable when gold is used as the thick film pattern.

For this reason, conventionally, the etching time for the thick film was set based on the thick part of the M hole to prevent short circuits between the formed thick film patterns.

However, in the conventional method as described above, over-etching of C occurs in thin film thickness parts, and this over-etching is one of the main causes of pattern breakage. However, in this method, the etching time varied depending on the difference in the thick film paste formed, so that the re-jamability of the formed pattern width was poor.

This invention was made in view of the above-mentioned circumstances, and it is possible to form a thick film pattern with high precision and good reproducibility even for films with non-uniform film thickness, and to achieve a thickness that is free from disconnections and short circuits. The purpose of the present invention is to provide a method for forming a film pattern.

In other words, when forming a desired thick film pattern using this invention, the etching process is repeated twice, and the dimensional width of the resist in the second etching process is equal to the dimensional width of the resist in the first etching process. A method in which the resist in the second etching process is subjected to ftfML to the samurai from which the resist in the first etching process has been removed;
Alternatively, there is a method of depositing the resist in the second etching process on the resist in the first etching process without removing it. In addition, in the first etching step, the etching time is set based on the average film thickness of the thick film, and in the second etching step, the maximum fullJlf of the thick film pattern formed in the first etching step is set.
By setting the etching time based on the above, it is possible to form a thick film pattern with higher accuracy.

Hereinafter, the method for forming a thick film pattern according to the present invention will be explained in detail with reference to an example shown in the accompanying drawings.

FIG. 1 (i) shows the manufacturing steps of an embodiment of the method for forming an n-film pattern according to the present invention in order;
This manufacturing method will be explained below in order of steps. In this embodiment, Aα is particularly used as the thick film material.

(a) A thick film material 2 is placed on a substrate 1 made of lamic or the like.
After the ALc paste is printed in a solid state using, for example, screen printing technology, it is fired at an appropriate temperature.

The thickness of the Ata paste thus formed has some variation as described above.

Thereafter, a desired pattern of positive resist 6 is formed on the AIJI film 2 using photolithography, and this is used as an etching mask for the ALj film 2. In this case, it is assumed that the AIJI2O3 turns must be formed especially over relatively thick parts and thin parts.

(b) The substrate 1 on which the Al1 film 2 and resist 6 are formed is immersed in, for example, an iodine-potassium iodide-based etching solution and etched. The etching time in this etching is set based on the average film thickness t of the ALiL film 2. Therefore, even in the portions of the Au film 2 to which the positive resist 3 is not attached, thick portions remain without being etched. The unplanned etched portions may cause short circuits with adjacent patterns.

(e) After the resist 6 is removed upon completion of etching, photolithography is performed again in order to remove the remaining portions that were not etched as planned.

In this second photolithography (the dimensions of the positive resist 6I used here are approximately 10 to 15 μm larger on one side than the dimensions of the resist 3 used in the steps (a) and (b) above. This is to improve dimensional accuracy by covering the progress of etching in the side direction caused by etching.

(d) The substrate 1 on which the second photoresist 6I has been formed is again immersed in the iodine-potassium iodide-based etching solution and etched again. The etching time for this second etching is set, for example, based on the maximum film thickness of the portion, so that the portion remaining unetched beyond the schedule is completely removed. At this time, since a resist having a size slightly larger than a predetermined size is formed in the portion desired to be left as a pattern, over-etching does not occur in this second etching. FIG. 1(d) is a cross section after the above etching is completed.

(e) Finally, the resist 3' is peeled off. In this way, the ff1ffl pattern of the Ate film 2 could be formed.

FIG. 2 shows another embodiment of the thick film pattern forming method according to the present invention according to its manufacturing process.

Note that the steps shown in FIGS. 2(a) and 2(b) are the same as those shown in FIG. 1(a).
Since this step is similar to step (b), its explanation will be omitted.

(e) In the embodiment shown in FIG. 1, after the first etching was completed, the resist 3 used in the first etching was removed, but in this embodiment, after the first etching was completed, the second For example, the substrate 1 in the state shown in FIG.
The resist 6 is left in a state of being insoluble in the solvent used during development in photolithography. Then, with the insoluble resist 6 attached, photolithography is performed again to remove the unplanned etched portions, as described above.

As described above, the dimensions of the positive resist 6' used in this second 7-otolithography are set to be larger, for example, by about 10 to 15 μm, than the dimensions of the resist 6 used in the first 7-otolithography. Set photomask dimensions.

(d) The substrate 1 on which the photoresists 6 and 6' have been formed is again immersed in an iodine-potassium iodide etching solution and etched to remove the portions that were not etched as planned. The etching time for this second etching is set, for example, based on the maximum film thickness of the remaining portion, so that all the unplanned remaining portions are removed, as described above.

(e) After completing the above etching, resists 3 and 6
1 is peeled off using, for example, the solvent used in the development described above and a mixed solution of sulfuric acid and hydrogen peroxide.

In this way, the ALIJ film 2 (7
) The desired pattern could be formed; however, in the case of this second example, the first layer resist 6 was made of gauze that did not dissolve in the solvent used in the photolithography development process for the second layer resist. Another advantage is that even if there is a defect in the photomask used for forming the second layer resist pattern, it will not become a defect in the pattern of AtL, M@2 itself.

As explained above, according to the method for forming a thick film pattern according to the present invention, (1) a thick film pattern with good thickness can be formed with good reproducibility even on a thick film with an uneven film thickness; I can do it.

(2) Disconnection and short circuit of thick film patterns can be prevented.

[Brief explanation of the drawing]

W; Figure 1 is a process diagram showing an embodiment of the method for forming a thick film pattern according to the present invention according to its manufacturing process, and Figure 82 is a process diagram showing another embodiment of the method for forming a thick film pattern according to the present invention. 1. Substrate, 2. Au film as thick film, 3, 5/
...Photoresist. Figure 1 Figure 2 500-

Claims (4)

[Claims] (1) In a method for forming a thick film pattern in which a desired thick film pattern is formed using a resist as an etching mask, a first etching step and a second etching step are performed in which the membrane pattern processed in the first etching step is etched again. 1. A method for forming a thick film pattern, comprising the steps of: forming an etching mask in the second etching step larger than an etching mask in the first etching step; (2) The etching mask in the etching step @2 is formed after the etching mask in the first etching step is removed.
A method for forming a thick film pattern as described in . (3) The method of forming a thick film pattern according to claim 1, wherein the etching mask in the second etching step is formed on an upper layer of the etching mask in the first etching step. (4) The etching time in the first etching step is based on the average film thickness of the thick film, and the etching time in the second etching step is the etching time in the first etching step.
The method for forming a thick film pattern according to claim 1, wherein the time is based on the maximum film thickness of the thick film pattern processed in the etching step.