JPS5946306B2 - Vapor deposition equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vapor deposition apparatus, and particularly to a vapor deposition apparatus capable of forming a thin film of uniform thickness.

In various fields including the semiconductor industry, vacuum evaporation methods, sputtering evaporation methods,
Gas phase reaction methods are widely practiced. In vapor deposition apparatuses, sputtering vapor deposition apparatuses that utilize the phenomenon of cathode sputtering caused by glow discharge are widely used for the purpose of forming thin films of various materials.

In this case, in order to reduce the thickness distribution of the deposited film, for example, the geometrical dimensions of the device are increased, the geometrical shape is made concentric spheres, or the substrate is rotated. Even if such efforts are made in sputtering deposition equipment, the variation in the thickness of the deposited film is still 20% even within the same rod.
It exists to some extent. The inventors set up a shield that partially shields the substrate from the target between the target and the substrate on which the film is to be formed, and also controlled the film thickness distribution by moving the shield and the substrate relative to each other. further reduce
It has become possible to reduce the variation to 3% or less (Japanese Unexamined Patent Publication No. 108885/1983).

The present invention facilitates temperature control of the substrate to be vapor-deposited by configuring the shielding body of this apparatus so as not to disturb the potential distribution in the discharge space, and reduces variation in film thickness and improves film quality. This makes it possible to easily produce thin films with little variation in crystallinity, electrical properties, piezoelectric properties, etc. One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1A is a sectional view showing the configuration of the electrode section.

In the figure, 1 is a spherical target electrode, 2 is a hemispherical shell-shaped substrate stand that also serves as an anode electrode, 3a, 3b, 3c,
3a', 3b', and 3c' are substrates, and 4 is a shield, and when viewed from the direction of arrow 5 in the figure, it looks like FIG. 1B.
A spherical copper target with a diameter of 70 mm was used as the target electrode 1, and a hemispherical shell-like body with an inner diameter of 250 mm was used as the substrate stand 2. Substrates 3a, 3b, 3c, 3a', 3b
25 mm square glass substrates were used as ', 3c', and a shield 4 processed into the shape shown in FIG. 1B was used. In the apparatus having this configuration, the target electrode 1 and the shield 4 are fixed, and sputtering vapor deposition is performed in an argon atmosphere while the substrate stage 2 is rotated around the target electrode 1.

Figure 2 shows the results.

FIG. 2A shows the film thickness distribution of the sputtered film obtained when the shielding body 4 was not used for the substrates 3a, 3b, and 3c. The shaded area 6 in the figure is the area where the thickness is 90% or more of the maximum film thickness. Figure B shows the thickness distribution of the sputtered film when the shield 4 is used. A shaded portion 7 in the figure indicates a portion having a film thickness of 90% or more of the maximum film thickness. From the figure, it can be seen that by using the shielding body 4, the portion of the deposited film having a uniform thickness is greatly expanded. As a result of detailed research and study on the above-mentioned apparatus, the inventors found that the uniformity or reproducibility of sputtering deposition changes depending on the potential of the shield.
They also discovered that there is an optimal shielding potential for sputtering deposition with good reproducibility.

In other words, according to experiments conducted by the inventors, when a glow discharge is generated by applying a negative voltage to the target electrode and a positive voltage to the anode electrode, the potential of the shield fixed to the anode electrode changes to the applied positive electrode. Since the potential is equal to the potential, the electric field strength on the target surface is non-uniform between parts with and without a shield.In sputtering deposition, specific parts of the target are subjected to more sputtering, and the target deforms over time. , found that the reproducibility of sputtering deposition changes. In addition, the electron density distribution near the substrate changes depending on the potential of the shield,
It was also discovered that the uniformity of the deposition was disturbed. The inventors
Based on this newly discovered fact, by controlling the potential of the shield, it was possible to solve the above-mentioned problems and improve the uniformity and reproducibility of vapor deposition. first,
As a result of installing the shield in an electrically insulated manner in the vacuum chamber, the potential of the shield becomes the potential of the discharge space where it is located, which does not disturb the electric field in the discharge space and maintains uniformity. It became like that.

However, if the shield is made of an insulator, the potential-related problem is solved, but the temperature of the shield increases due to glow discharge, and the temperature of the substrate increases due to heat radiation from the shield, which reduces the reproducibility of the film quality. It was easy to cause deterioration. This problem could be solved by forming the shield from a metal with good thermal conductivity and applying a voltage corresponding to the potential of the discharge space where it is located. As is clear from the above description, the vapor deposition apparatus according to the present invention has a structure in which a shielding plate is disposed between the target and the substrate to partially shield the substrate from the evaporation source. By maintaining the potential at the location in the discharge space, there is no risk of disturbing the electric field distribution in the discharge space, and a thin film with uniform film quality and less variation in film thickness can be easily formed. can do.

Therefore, this equipment can be used in semiconductor manufacturing processes, etc.
It is useful for use in various thin film manufacturing processes.

[Brief explanation of drawings]

FIG. 1A is a sectional view showing the structure of a main part of an embodiment of a vapor deposition apparatus according to the present invention, and FIG. 1B is a plan view showing the structure of a portion thereof. FIG. 2A is a diagram showing variations in the thickness of a vapor deposited film formed by the vapor deposition apparatus before improvement, and FIG. 2B is a diagram showing variations in the film thickness of the vapor deposited film formed by the vapor deposition apparatus of the present invention. 1...
...Target electrode, 2...Substrate stand that also serves as an anode electrode, 3a, 3b, 3c23a3b3c''...
... Board, 4... Shielding body.

Claims (1)

[Claims] 1. A target electrode that is an evaporation source, a substrate placed facing the target electrode, an anode electrode that fixes the substrate, and a shield that partially shields the substrate from the target electrode. holding the potential of the shield equal to the potential of the discharge space in which the shield is located, or electrically insulating the shield, while causing the substrate and the shield to move relative to each other, A deposition apparatus that deposits a material for the target electrode onto the substrate.