JPH07278784A - Mask for forming thin film - Google Patents

Abstract

PURPOSE:To provide a mask which is long in washing intervals (the number of times to be continuously used in vapor deposition by sputtering) of the mask to be used for vapor deposition by sputtering and is decreased in the variations in the washing intervals of the mask. CONSTITUTION:The surface of this mask 10 for forming thin films to be used for forming coatings of prescribed patterns on the surface of a blank body via the mask 10 by the particles splashed from a splashing source is roughened. The surface roughness (Ra) of the mask surface is >=0.4mum and the mask consists of metal or rubber-like elastic material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mask used for forming a predetermined pattern on the surface of an element body in a dry thin film forming method such as sputter deposition.

[0002]

2. Description of the Related Art Dry film forming methods include sputter deposition, vacuum deposition, ion plating and the like. Here, a thin film forming method by sputter deposition will be described as an example.

Sputter evaporation means that when high-energy particles irradiate a surface of a scattering source (target), the high-energy particles collide with constituent atoms on the surface of the scattering source, and as a result, constituent atoms on the surface of the scattering source scatter. Evaporation from the surface. It is called sputter vapor deposition that deposits the constituent atoms on the surface of the scattered source vaporized by sputtering to form a vapor deposition film on the surface of an element body which is an object to be vapor deposited. At this time, the sputter deposited film is formed almost uniformly on the surface of the element body.

There is a method of forming electrodes of electronic parts by sputter-depositing an electrode material, which is a scattering source, by using the above-mentioned sputter-deposition method. A conventional thin film forming mask for forming electrodes using this method will be described with reference to FIG.

The mask 1 is made of, for example, a stainless metal plate, and has through holes 2 corresponding to predetermined electrode patterns.

When the mask 1 is used to cover the surface of an element body 3 which is an electronic component and a scattering source 4 made of an electrode material is sputter-deposited, the electrode material corresponds to the through hole 2 of the mask 1 and the element body 3 is formed. The film is deposited on the surface of as a sputter-deposited film. At this time, the electrode material is also deposited on the surface of the mask 1.

Next, when the mask 1 is separated from the element body 3,
On the surface of the element body 3, except for the portion covered by the mask 1, a sputtered vapor deposition film is deposited to form an electrode 5 having a predetermined pattern.

[0008]

However, when the mask 1 having such a structure is repeatedly used for sputter deposition,
The sputter-deposited film, which is an electrode material, is deposited on the surface of the mask 1 so that the sputter-deposited film becomes thicker according to the number of times of use. When the thickness of the sputter-deposited film reaches several tens of μm, for example, the sputter-deposited film piece is peeled off from the mask 1 due to thermal stress at the time of sputtering. When the scattering source 4 is located below the element body 3, when the separated sputtered vapor deposition film pieces fall onto the scattering source 4, the scattering source 4 having a negative potential is used.
And a frame or the like (not shown) grounded to stop the sputter deposition apparatus, and the sputtered deposition film pieces that have fallen off before sputter deposition are used for the element body 3
If the upper surface is covered, the sputter-deposited film piece subsequently covers a part of the surface of the element body 3 when sputter-deposited, so that the electrode 5 is not formed on a part of the predetermined pattern. Had.

In order to prevent the above-mentioned problems, the mask 1 is used for sputter deposition several times to several times in succession, and then the mask 1 is subjected to a chemical or physical method, for example, an acid chemical. There is a problem in that the unnecessary sputtered vapor deposition film deposited on the surface of (1) must be removed (hereinafter referred to as cleaning).

An object of the present invention is to solve the above-mentioned problems, and a mask having a long cleaning interval for a mask used for sputter deposition (the number of consecutive sputter deposition uses) and a small variation in the cleaning interval of the mask. To provide.

[0011]

Therefore, in the present invention, in a thin film forming mask for forming a coating of a predetermined pattern on the surface of an element body through a mask by scattered particles from a scattering source, It is characterized in that the surface of the mask is roughened.

The surface roughness (Ra) of the surface of the mask is 0.4 μm or more, and the mask is made of a metal or rubber-like elastic material.

[0013]

That is, in the present invention, by increasing the surface roughness of the mask, the adhesion between the sputter-deposited film formed on the mask surface and the mask is improved, and the sputter-deposited film is less likely to peel off from the mask surface. .

[0014]

An embodiment of the present invention will be described below with reference to FIG. The mask 10 according to the present invention is made of, for example, a stainless steel plate of SUS304, has through holes 11 having the same pattern as the electrodes 5 formed on the element body 3, as already shown in FIG. For example, the main surface of at least one of the masks 10 is roughened by a sandblasting method, which is a physical method of spraying abrasive grains to roughen the surface.

As in the conventional example shown in FIG. 2, the mask 10 is used to cover the element body 3 and, for example, an electrode material which is a constituent atom of the scattering source 4 is deposited by sputtering. The electrode 5 having a predetermined pattern is formed, and the sputter-deposited film is also deposited on the surface of the mask 10.

However, the mask 10 having a roughened surface is
The sputter-deposited film deposited on the surface is less likely to peel off, and the number of times of continuous sputter-deposition can be increased as compared with the conventional mask 1 in which the surface is not roughened.

Table 1 shows the results of examining the relationship between the surface roughness of the conventional mask 1 and the mask 10 according to the present invention and the number of times of continuous use before the peeling of the sputter deposited film starts.

As is clear from Table 1, as the surface roughness of the mask 10 of the embodiment becomes rough, the number of continuous uses until the peeling of the sputtered vapor deposition film starts increases. That is,
If the surface roughness of the mask 10 is increased, the number of times the mask 10 can be continuously used for sputter deposition is increased, and the number of times of cleaning can be reduced. For example, as compared with the mask 1 of the conventional example, it can be seen that the number of times that the mask can be continuously used for sputter deposition can be extended to about 5 times longer.

[0019]

[Table 1]

Next, the mask 10 was repeatedly used for the sputter deposition in order to investigate the influence of the peeling of the sputter deposited film depending on the number of times of cleaning the mask 10. That is, Table 2 shows the results of an experiment in which the mask 10 is washed if peeling of the sputter deposited film occurs, and then repeatedly used for sputter deposition again. Table 2 shows the number of times of the sputter vapor deposition until the peeling of the sputtered vapor deposition film occurs during the number of times of cleaning, the average value of the number of sputter vapor depositions, and the deviation value (σ _n-1 ).
showed that. Table 2 also shows conventional examples as comparative data.

[0021]

[Table 2]

As is clear from Table 2, in the mask 10 according to the present invention, the number of times the sputter-deposited film starts to peel off is a stable value of about 54 regardless of the number of times of cleaning. Therefore, when the mask 10 according to the present invention is used, it is possible to prevent the sputter-deposited film pieces from peeling off from the mask 10 by regularly cleaning the mask 10.
It is possible to prevent a short circuit between the scattering source and the frame or the like to stop the sputter deposition apparatus or to drop onto the element body 3 to cause defective electrode formation.

Although the mask 10 of the present invention has been described by using an example of using it for sputter deposition, it can be generally used for dry thin film forming masks such as vacuum deposition and ion plating.

The method of roughening the surface of the mask 10 is not limited to the physical sandblasting method, and other physical methods may be used. For example, an acid-based method such as sulfuric acid and hydrochloric acid may be used. A chemical method using a chemical may be used. The material of the mask 10 is not limited to metal stainless steel, but may be another metal, for example, a rubber-like elastic body may be used.

[0025]

As described above, in the thin film forming mask according to the present invention, by making the surface roughness of the mask rough, it is possible to deposit the sputtered vapor deposition film by sputter vapor deposition on the mask surface in a state in which it is difficult to peel off. did it. Therefore, when the mask according to the present invention is repeatedly used for sputter deposition, the number of times it can be used continuously increases. Further, the number of times of cleaning the mask per sputter deposition can be reduced, and the life of the mask is extended.

Further, since the mask cleaning interval can be made substantially constant, the mask can be cleaned regularly.

[Brief description of drawings]

FIG. 1 is a front sectional view of a mask according to the present invention.

FIG. 2 is an exploded perspective view of a conventional sputter deposition.

[Explanation of symbols]

 3 Element 4 Scattering Source 5 Electrode 10 Mask

Claims (5)

[Claims] 1. A thin film forming mask for forming a coating of a predetermined pattern on a surface of an element body through a mask by scattered particles from a scattering source, wherein the surface of the thin film forming mask is roughened. Mask for thin film formation. 2. The mask for forming a thin film according to claim 1, wherein the surface of the mask is roughened by acid or sandblast. 3. A thin film forming mask for forming a coating of a predetermined pattern on a surface of an element body through a mask by scattered particles from a scattering source, wherein the surface roughness (Ra) of the surface of the thin film forming mask is A thin film forming mask having a thickness of 0.4 to 10 μm. 4. The thin film forming mask according to claim 1, wherein the mask is made of metal. 5. The thin film forming mask according to claim 1, wherein the mask is made of a rubber-like elastic material.