JPH03212923A - Forming method of tin-film multilayer substrate - Google Patents

Abstract

PURPOSE:To improve precision in alignment and thereby to improve productivity by forming an alignment mark in an alignment region simultaneously in a process wherein a thin-film pattern constructed of a thick insulation film is formed on a thin-film pattern constructed of a conductive film and by providing the alignment mark with a stepped part. CONSTITUTION:A metal film 10 is deposited on the whole surface of a substrate 1 and subjected to photoetching and thereby an alignment region made up of a thin-film pattern P1, a cross pattern 10a and a square pattern 10b is formed. Next, an insulating film 12 constituted of photosensitive polyimide resin is connected about 10mum thick on the whole surface of the substrate 1 and etched, so as to form marks 12a and 12b simultaneously with a pattern P2. A metal film 14 is evaporated thereafter. According to this constitution, a stepped surface 14a always appears even when a plurality of thin films are laminated on the marks 12a and 12b, and productivity is improved without lowering of precision in alignment.

Description

[Detailed Description of the Invention] [Summary] Regarding a method for forming a thin film multilayer substrate, the purpose of this invention is to improve productivity by improving the alignment accuracy of thin films sequentially laminated on an insulating substrate. A method for forming a thin film multilayer substrate in which a first thin film pattern made of a conductive film is formed in a predetermined region of an insulating substrate, and an alignment region of a predetermined shape is simultaneously formed at least near the outside of the pattern formation region. and forming a second thin film pattern made of an insulating film that is sufficiently thicker than the thin film at a position corresponding to the first thin film pattern, in the alignment area provided at the time of forming the first thin film pattern. , an alignment mark having a predetermined shape and having a size not exceeding the alignment area is simultaneously formed.

[Industrial application field]

The present invention relates to a process for forming a thin film on a thin film multilayer substrate, and more particularly to a method for forming a thin film multilayer substrate in which productivity is improved by improving alignment accuracy of thin films that are sequentially laminated.

In the manufacturing process of a thin film multilayer substrate in which a plurality of thin films are sequentially formed on a substrate, normally when forming the bottom thin film, a cross-shaped alignment mark, for example, is simultaneously formed outside the frame of the required area of the thin film, and an alignment mark is formed on the thin film. In the post-process, in which multiple thin films are sequentially formed in layers, each pattern is aligned using the alignment mark as a reference. Since deviations occur, a solution is desired.

[Conventional technology]

FIG. 2 is a process diagram illustrating an example of a conventional method for forming a thin film multilayer substrate, and the figure shows a metal film and an insulating film.

A case is shown in which three thin films of metal films are sequentially formed.

The figure shows a stepping exposure machine (exposing with the mask separated from the photosensitive resist and developing it.

In this case, a desired thin film pattern is formed by etching.

In figure (1), 1 has a thickness of 1 mm and a size of, for example, 114 m.
This is a glass-ceramic multilayer substrate (hereinafter simply referred to as the substrate) of m×95 mm, and a plurality of through holes la are provided at predetermined positions in the thin film formation region of the substrate I, which are electrically connected to the front and back surfaces.

Normally, in order to form a thin film multilayer substrate using such a substrate, first the substrate l is made into a size of, for example, 22 mm x 22 mm, as shown by the broken line a.
Cell Sl of size 32. Separate into Ss...',
Sl.

S2. After exposure in the order of Ss..., predetermined development is performed on the vaginal substrate 1.

Each cell Sl, S2. Ss・
After forming a first layer of thin film on . Ss...
Three layers of thin film are laminated on top of each other.

The process of laminating each of the above thin films will be explained in detail below, but in order to make it easier to understand, the figure shows the case where one cell portion is enlarged and each of the above thin films is laminated on one side of the cell. .

First, a Cr/Cu/Cr metal film 2 with a thickness of about 5,000 layers is deposited on the entire surface of the substrate 1 using a normal sputtering technique.
After applying a negative resist to the entire surface of the metal film 2, a first mask 3 in which the required pattern PT of the first layer is cut out as a hole is placed at a predetermined position above the substrate 1. Then, the state shown in (2-1) is obtained. In particular, in this case, a cross hole 3a and a square hole 3b are provided at predetermined positions outside the area of the above-mentioned required pattern indicated by the dotted line of the mask 3. .

In this case, the positioning of the first mask 3 with respect to the substrate 1 and thus the cells is performed using the light passing through the patterned portion of the mask 3 and the plurality of through holes l located in each cell area.
This can be easily done by matching a.

Therefore, after performing a predetermined exposure on the cells S, , S, , S, . Only the portions corresponding to the cross hole 3a and the square hole 3b remain, and by peeling off the resist in these portions, the desired pattern P of the metal film 2 is formed as shown in (2-2)! A first thin film pattern layer having a cross pattern 2a and a square pattern 2b can be obtained.

Next, after applying an insulating film 4 made of photosensitive polyimide resin to a thickness of about several μm over the entire surface of the substrate l, a hole is cut out with a required pattern p2 of the second layer at a predetermined position above the cell. When the mask 5 of No. 2 is placed, the state shown in (3-1) is obtained, but in this case, the mask 5 has a corresponding position outside the pattern p2 area already indicated by the dotted line and at a position corresponding to the cross hole 3a of the mask 3. Cross hole 5a of the same size as cross hole 3a
However, a cross hole 5b, which is somewhat smaller than the square hole 3b, is provided at a position corresponding to the square hole 3b.

Therefore, the mask 5 is positioned with respect to the cell by aligning the light passing through the cross hole 5a of the mask 5 with the cross pattern 2a on the cell, and then a predetermined exposure is performed and development is performed, similar to a normal photosensitive resist. The above insulating film 4 having the properties of
can be left only in the exposed portions of the mask 5, that is, the portions corresponding to the pattern p2 and the cross holes 5a and 5b.

Therefore, in the pattern area of each cell, the second layer pattern P
2 is stacked as PI+P2, and cross pattern 2
Above a is a cross pattern 4a corresponding to the cross hole 5a.
However, the cross patterns 4b corresponding to the cross holes 5b are laminated on the square patterns 2b.

In this case, the cross pattern 2a used for the alignment work between the mask 5 and the cell is made of a metal film and is formed on glass ceramic.

Therefore, since the cross pattern 2a is easy to recognize, the mask 5 and the cells can be easily aligned.

Therefore, the required insulating film 4 can be formed by baking and hardening the polyimide resin at a temperature of about 350 to 400°C.

(3-2) shows this state.

After that, similarly to the case (2-1), a Cr/Cu/Cr metal film 6 with a thickness of about 50,001 mm was deposited on the entire surface of the substrate 1 by sputtering, and a negative resist was further applied on the entire surface, and then
When a third mask 7 in which the required pattern p of the third layer is cut out as a hole is placed at a predetermined position above the cell (4-
The state shown in 1) is reached, but in particular, at a position corresponding to the cross hole 5b of the second mask 5 outside the thin film pattern forming area already indicated by the dotted line of the mask 7, there is a hole of the same size as the cross hole 5b. A cross hole 7a is provided.

Therefore, after positioning the mask 7 with respect to the cell so that the light passing through the cross hole 7a of the mask 7 matches the cross pattern 4b on the square pattern 2b of the cell, (2-1
) When the same exposure, development, and etching processes of the metal film 6 are performed as in the case of ), a pattern P3 corresponding to the pattern p3 of the third mask 7 is laminated on each cell with a resist placed thereon. By peeling off the resist, each cell has the required PI +P2 +P as shown in (4-2).
It is possible to obtain three thin film layers consisting of .

Particularly in this case, since the second-layer insulating film pattern is sandwiched between the -th-layer metal film pattern and the third-layer metal film pattern, any circuit can be created by appropriately setting each pattern. Can be configured.

However, as described above, the cross pattern 4b made of the insulating film 4 of each cell used for positioning the mask 7 in this case is thin, on the order of a few μI diameter, so the cross pattern 4b cannot be clearly recognized. As a result, it may take a long time to align the mask with respect to the cells, or alignment accuracy may decrease, resulting in pattern deviation.

[Problem to be solved by the invention]

In the conventional method for forming thin film multilayer substrates, layers are formed one after another based on the alignment mark provided on the cell. There is a problem in that the realignment accuracy that takes a long time for alignment may deteriorate, resulting in pattern misalignment, and that productivity cannot be expected to improve.

[Means to solve the problem]

The above problem lies in a method for forming a thin film multilayer substrate in which a plurality of thin film patterns are sequentially laminated on an insulating substrate. An alignment region of a predetermined shape is simultaneously formed near the outside of the region, and a second thin film pattern made of an insulating film that is sufficiently thicker than the thin film is formed at a position corresponding to the first thin film pattern. This problem is solved by a method for forming a thin film multilayer substrate in which an alignment mark of a predetermined shape and a size not exceeding the alignment area is simultaneously formed in the alignment area provided during the formation of the first thin film pattern.

[For production]

When the alignment mark is formed to have a sufficient level difference, it is possible to easily match the light passing through the mask pattern with the alignment mark.

In the present invention, the thickness of the second insulating film provided between the first thin film pattern and the third thin film pattern made of a metal film is increased, for example, to about 10 μm, and when forming the insulating film, An alignment mark made of the insulating film is formed on the alignment region of the first layer thin film pattern.

In this case, an alignment mark made of an insulating film with a thickness of about IO μm protrudes above the alignment region of the −th thin film.

Therefore, even if a plurality of thin films are laminated on the alignment mark, the stepped surface always appears, so the alignment mark does not become difficult to see or the alignment accuracy decreases, and productivity can be improved.

〔Example〕

FIG. 1 is a process diagram illustrating a method for forming a thin film multilayer substrate according to the present invention.

The figure shows the case where three layers of thin films are laminated as in FIG. 2, and only the cell portion is shown in an enlarged state as in FIG. 2.

In the figure, numeral 1 is the glass ceramic laminated substrate (hereinafter referred to simply as the substrate) described in FIG. 2, and the broken line a is a line dividing cells, and the nine-dot line is a line representing a pattern forming area. Note that the plurality of 1a located in the pattern forming area represent through holes that are electrically connected to both sides.

First, a Cr/Cu/Cr metal film 10 having a thickness of approximately 5,000 layers was deposited on the entire surface of the substrate 1 in the same manner as in the case of FIG. 2, and a negative resist was further applied on the entire surface of the metal film 10. After that, if the first mask 11 in which the required pattern p1 of the first layer is cut out as a hole is placed at a predetermined position above the corresponding cell, the state shown in (A-1) will be obtained, especially the dotted line of the mask 11. A cross hole 11a and a square hole 11b are provided at predetermined positions outside the thin film pattern forming area already shown.

Therefore, after positioning the mask 11 relative to the cell so that the light passing through the patterned portion of the mask 11 matches the through-hole la of the cell, the mask 11 is exposed in a predetermined order as explained in FIG. After developing and etching the metal film 1-1, each cell region is covered with a resist on top of the metal film corresponding to the pattern p1 of the mask 11, the cross hole 11a, and the square hole 11b. It can be left in the same condition.

Therefore, by peeling off the resist, a desired pattern P made of the metal film IO, a cross pattern IOa, and a square pattern IOb are formed as shown in FIG. A first layer thin film pattern can be obtained.

Next, on the entire surface of the substrate 1, an insulating film 12 made of photosensitive polyimide resin similar to that shown in FIG. If the second mask 13 with holes cut out is placed, the state shown in (B-1) will be obtained, but in this case, the cross hole of the mask 11 will be located outside the pattern forming area indicated by the dotted line of the mask 13. A cross hole 13a having the same size as the cross hole 11a is provided at a position corresponding to the cross hole 11a, and a cross hole 13a slightly smaller than the square hole 11b is provided at a position corresponding to the square hole 11b.

Therefore, when the mask 13 is positioned with respect to the substrate l by aligning the light passing through the cross hole 13a of the mask I3 with the cross pattern loa on the cell and predetermined exposure and development are performed, the exposed portion is Only insulating pus can be left behind.

Therefore, a second layer pattern P2 with a thickness of 10 μm is laminated on the pattern P1 of each cell, and a cross pattern 10
Above a, there is a cross pattern 12a of the same thickness corresponding to the cross hole 13a, and further above the square pattern 10b is a cross pattern 12 of the same thickness corresponding to the cross hole 13b.
b are stacked on top of each other.

In this case, the alignment of the mask 13 with respect to the substrate 1 is easy as explained in FIG. 2.

Therefore, by firing the polyimide resin at about 350 to 400°C, a desired insulating film pattern as the second layer can be obtained, but at the same time, a cross pattern 12a made of an insulating film is formed on the cross pattern 10a of the substrate 1. , and a cross pattern 12b made of an insulating film is formed on the square pattern 10b.
are each formed to have a thickness of about IO μm, resulting in the state shown in (A-2).

Next, in order to form a third layer of metal film, a metal film 1 similar to (A-1) is deposited on the entire surface of the substrate 1 as explained in FIG.
4 is sputter-deposited and a negative resist is applied to the entire surface, and then a third mask 1 is formed in which a required pattern p of the third layer is cut out in the form of a hole at a predetermined position above the corresponding cell.
When 5 is placed, part B of (B-2) is enlarged (C-1)
The situation will be as follows.

Particularly in this case, the thickness of the insulating film 12 is the same as that of the metal film 15.
Because it is sufficiently thicker than the thickness of the insulating film 1, as shown in the figure,
A shape that almost matches the pattern No. 2 stands out, and at the same time, almost the outer shape of the cross pattern 12b also appears, and a step surface 14a is formed around it.

Note that the cross hole 13b of the second mask 13 is located outside the area of the thin film pattern p3 already indicated by the dotted line of the mask 5.
A cross hole 15a having the same size as the cross hole 13b is provided at a position corresponding to the cross hole 13b.

Therefore, after positioning the light passing through the cross hole 15a of the mask 15 with respect to the cell using the stepped surface 14a as a reference, the same exposure, development, and etching processes as in the case (A-1) are performed. In the cell area, a pattern corresponding to pattern p of the third mask 15 is newly laminated as in the case of FIG. 2, thereby making it possible to obtain the required three thin film layers.

(C-2) shows a part of the required pattern section in cross section, 1 is the substrate, 10 is the first layer pattern consisting of the metal film IO, 12 is the second layer pattern consisting of the insulating film 12, 1
4 represents the third layer pattern made of the metal film 14, respectively.

Therefore, any circuit can be constructed by appropriately setting each pattern as in FIG. 2.

Particularly in this case, the thickness of the cross pattern 12b on the substrate l used for positioning the mask 15 and thus on the cell is about I.
Since it is as thick as 0 μm, when positioning is performed using light passing through the cross hole 15a of the mask 15, the position can be detected by the stepped surface 14a of the metal film 14 corresponding to the cross pattern 12b, so that the mask 15 can be easily positioned. I can do it.

Note that the cross pattern 12b formed by the insulating film 12 is sufficiently thick compared to the thickness of the thin film, so even when another thin film is formed on the third metal film 14, the stepped surface can be used. Thus, a thin film multilayer substrate can be easily formed.

[Effect of birth]

As described above, according to the present invention, it is possible to provide a method for forming a thin film multilayer substrate in which productivity is improved by increasing the alignment accuracy of thin films sequentially laminated on an insulating substrate.

[Brief explanation of drawings]

FIG. 1 is a process diagram illustrating a method for forming a thin film multilayer substrate according to the present invention, and FIG. 2 is a process diagram illustrating an example of a conventional method for forming a thin film multilayer substrate. In the figure, ■ is a glass ceramic multilayer substrate (insulating substrate), 1a is a through hole, 10.14 is a metal film, 10a, 12a
, 12b is a cross pattern (alignment area), 11 is a first mask, Ila, 13a and 13b are cross holes, 11b is a square hole, and 13 is a second mask. 12 is an insulating film, 15 is a third mask,

Claims (1)

[Claims] A method for forming a thin film multilayer substrate in which a plurality of thin film patterns are sequentially laminated on an insulating substrate, the method comprising: forming a first thin film pattern made of a conductive film in a predetermined region of an insulating substrate (1); , an alignment region (10a, 1
0b) at the same time, and when forming a second thin film pattern consisting of an insulating film that is sufficiently thicker than the thin film at a position corresponding to the first thin film pattern, Alignment marks (12a, 12b) of a predetermined shape with a size not exceeding the alignment area (10a, 10b) are placed in the alignment area (10a, 10b).
) is formed at the same time.