JPS6137965A - Deposited film forming apparatus - Google Patents

Abstract

PURPOSE:To form a film having rapid forming rate and good quality and to suppress film entering the desired part, by setting the ratio of height to width of an opening hole part in a film mask provided for forming partial film on a substrate. CONSTITUTION:In deposited film forming apparatus in which material gas is decomposed by generating discharge between electrodes to form deposited film on the substrate, height of a mask 26 for forming film partially on said substrate is prescribed to about 0.3-2.0mm., the ratio C/B of a height B to a bottom width C of opened hole parts provided at least >=3 holes is set to >=4. In this way, even in case a distance A in longitudinal direction of opening hole part of the mask 26 is >=200mm., deformation thereof is prevented, film entering the masked part is suppressed, and decrease of film formation rate is prevented. Said mask 26 is formed by using alumina or glass, and it is desirable to form the bottom surface and the upper part of the mask part to plane and tapered states, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a deposited film forming apparatus that deposits and forms a thin film on a substrate by utilizing a discharge phenomenon. The present invention relates to a deposited film forming apparatus that can be used.

[Prior Art I] Deposited film forming apparatuses are widely used for forming high-quality passivation films of 5i02, 5i3Na, etc. at low temperatures, or for forming amorphous silicon films used in solar cells, TPT, sensors, etc.

FIG. 1 is a sectional view of a deposited film forming apparatus having a parallel plate electrode structure. In FIG. 1, a cathode electrode 11 and a counter electrode 12 having a flat plate portion parallel to the surface of the cathode electrode 11 are arranged in a vacuum chamber IO.
A substrate holder (not shown) is fixed to the surface facing the cathode electrode 11 of No. 2. The counter electrode 12 is grounded. The vacuum chamber IO is evacuated to a high vacuum by an exhaust system 10a connected to an exhaust port formed on its peripheral wall, and then adjusted to a predetermined gas pressure by a gas system 15, and a predetermined voltage is applied to the cathode electrode 11 by a power supply system 14. is applied, and a discharge is caused between this electrode 11 and the counter electrode 12.

Due to this discharge, the source gas supplied from the gas system 15 is decomposed in the vacuum chamber 10, and a deposited film is formed on the substrate 13 supported by the substrate holder.

FIG. 2 is a sectional view of a deposited film forming apparatus having a coaxial electrode structure. In FIG. 2, a cathode electrode 21 having a cylindrical structure is provided in a vacuum chamber 20, and a counter electrode 22 having a cylindrical portion disposed on the outside of the cathode electrode 21 so as to be coaxial with the cathode electrode 21. The substrate 13 is supported by a substrate holder (not shown) fixed inside the electrode 22 . The vacuum chamber 20 is evacuated to a high vacuum by an exhaust system 20a connected to an exhaust port formed on its peripheral wall, and then adjusted to a predetermined gas pressure by the gas system 15, and a predetermined voltage is applied to the cathode electrode 21 by the power supply system 14. applied to this electrode 21
A discharge is generated between the electrode 22 and the opposite electrode 22. Due to this discharge, the source gas supplied from the gas system 15 is decomposed in the vacuum chamber 20, and a deposited film is formed on the substrate 13 supported by the substrate holder.

3 and 4 show a cross section of a substrate holder used in a parallel plate type deposited film forming apparatus and a coaxial type deposited film forming apparatus, and the film forming mask 16 shown in FIG. 6 is tightly attached to the surface of the substrate 13. It is arranged as follows. FIG. 5 is a sectional view of a substrate holder that also serves as a mask.

In FIGS. 3 and 4, a plurality of substrates 13 are fixed to a substrate holder 18 together with a mask 16. As shown in FIGS. Further, in FIG. 5, the substrate holder 18 also serves as a mask, and the substrate 13 is fixed to this.

However, since such a mask 18 and a substrate holder 18 that also serves as a mask are conventionally made of a metal material such as stainless steel, the opening 17 of the film forming area may have a rectangular shape, for example, as shown in FIG. In this case, when mask portion 18 is exposed to plasma, it warps, and when a film is further deposited on the mask, the stress causes mask portion 18 to warp further, causing substrate 13 and mask 16 to separate. For this reason, there is a drawback that when a thin film is deposited, the film wraps around unnecessary portions on the substrate 13.

This is particularly noticeable when a single substrate has a large number of elongated film formation parts.

In order to solve this problem, for example, the film forming mask 1
6 is made thicker, or as shown in FIG. 5, the substrate holder 18 is also used as a mask, so that the thickness of the mask is substantially increased.

However, when the thickness of the mask portion is increased, the rate of film formation on a desired portion of the substrate 13 becomes slow, and furthermore, there is a serious drawback that the film quality is significantly affected by the material of the mask 1B and deteriorates. This is fatal in the case of a mask having a short opening in the width direction and a large number of openings.

Furthermore, in order to solve this problem, after forming a film on the entire substrate 13, etching is performed leaving only a desired portion, thereby obtaining substantially the same result as forming a film partially. However, this has the disadvantage of increasing costs due to the increase in the number of steps, and furthermore, when creating a device with a multilayer structure, there is a disadvantage that step breaks occur at the step part of the film due to etching. . This was even more remarkable when the second layer film needed to be thinner than the first layer film.

[Object 1] The object of the present invention is to provide a deposition KN III forming apparatus that can eliminate the above-mentioned conventional drawbacks, prevent the thin film from wrapping around the desired portion of the substrate, and form a high-quality film at a high film-forming speed. It is about providing.

[Example 1 Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 7(a) is a perspective view of one embodiment of a film-forming mask 26 according to the present invention, and FIG. 7(b) is a sectional view of the same mask 26. As shown, A is the length in the longitudinal direction of the opening of the mask 2B, B is the height of the mask 2B, C is the bottom width of the opening of the mask 26, and 0 is the bottom width of the mask portion of the mask 26. . The opening has a taper if necessary, and the mask portion has a flat portion on its surface.

The results of the influence of the C/B ratio on the film formation rate according to the present invention are shown in FIG. As shown in FIG. 8, when the C/B ratio was at least 4 or more, no decrease in the film formation rate was observed and the properties of the deposited film were good.

Furthermore, when there are many openings on the same substrate, the 8 dimensions are 0.3 to 2. (With jam, a good deposited film could be obtained regardless of the C dimension of several III m.

In addition, in the case of 8 dimensions of 1 m + a or more, sharp irregularities on the mask can be eliminated by attaching a taper at an angle of 15 to 60 degrees, preferably 30 to 45 degrees to the opening, using the mask surface as a reference plane. Therefore, there is no concentration of plasma,
Furthermore, deterioration of film quality due to the influence of the mask material on the film could be prevented.

Ceramics such as glass and alumina have been used as materials to realize such masks, and have shown very good characteristics.

FIG. 8(a) is a perspective view of another embodiment of the film forming mask according to the present invention which also serves as a substrate holder, and FIG. 8(b) is a sectional view thereof. In this embodiment, when A at the opening of the film-forming mask 27 that also serves as a substrate is 200 mm or more, the C/B ratio is at least 4 or more, and the 8 dimensions are 0.3 to 2, as in the previous embodiment. Mask 27, which had a thickness of 0.0 mm and was made of glass and alumina, showed similarly good results.

Note that although only a film-forming mask with a rectangular appearance is shown, the present invention can be applied to a film-forming mask that has a rectangular shape with an opening of 200 mm or more even if the external appearance is a disc. Needless to say, it is.

As mentioned above, the A dimension is 200 mm as a mask for film formation.
In the above case, the C/B ratio is 4 or more, and the 8 dimensions are 0.3 to 2.
By setting the film thickness to 0 mm and forming the film formation mask with glass or alumina, the mask part will not warp even if the film adheres to the mask part or plasma is generated, and the film will not wrap around to unnecessary parts because it is in good contact with the substrate. The effect was that it could be prevented. Furthermore, since the mask portion can be made thinner than in the case of metal, the C/B ratio can be substantially increased, which has the effect of preventing a decrease in the film formation rate. Furthermore, since the film can be deposited only on the necessary parts, there is no need to perform an etching process on unnecessary parts, and the process can be shortened.

[Effect 1] As described above, according to the present invention, it is possible to provide a deposited film forming apparatus that can form a film only on a desired portion of a substrate and has a high film formation rate.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a deposited film forming apparatus with a parallel plate electrode structure, Figure 2 is a cross-sectional view of a deposited film forming apparatus with a coaxial electrode structure, and Figures 3 and 4 are a conventional substrate holder and film forming apparatus. A schematic cross-sectional view showing the arrangement with a mask. Figure 5 is a schematic cross-sectional view showing an integrated type of conventional substrate holder and film-forming mask, Figure 8 is a front view of a conventional film-forming mask, and Figures 7 (a) and 8 (a) are FIG. 1 is a perspective view showing an embodiment of a film forming mask according to the invention. FIG. 7(b) and FIG. 8(b) are sectional views of the same, and FIG. 9 is an explanatory diagram of experimental results according to the present invention. 10.20... Vacuum chamber, 11.21... Cathode electrode, 12.22... Counter electrode, 13... Substrate, 14... Power supply system, 15... Gas system, 16... - Mask for film formation, 17... Opening part, 18... Mask part, 18... Substrate holder. Figure 1 Figure 2 Figure 3/To Figure 5 To Figure 41 Figure 6

Claims (1)

[Scope of Claims] 1) In a deposited film forming apparatus that decomposes a source gas using a discharge phenomenon between electrodes and forms a deposited film on a substrate, an opening for partially forming a film on the substrate is provided. A deposited film forming apparatus comprising a film forming mask having a height to width ratio (height/width) of 4 or more. 2) The deposited film forming apparatus according to claim 1, wherein the film forming mask has at least three or more openings. 3) The longitudinal direction of the opening of the film forming mask is at least 2
The deposited film forming apparatus according to claim 1, wherein the deposited film forming apparatus has a thickness of 00 mm or more. 4) The deposited film forming apparatus according to claim 1, wherein alumina or glass is used for the film forming mask.