JPH0525647A - Plasma vapor growth method - Google Patents

Abstract

PURPOSE:To lessen the generation of powdery deposits in plasma vapor growth. CONSTITUTION:An upper electrode 3 and lower electrode 2 of parallel flat plate electrodes of this plasma vapor growth device are substantially flat over the entire surface including the peripheral edges of the electrode surfaces facing each other and the surfaces thereof exclusive of the regions of the electrode surfaces facing each other are coated with a chemically stable insulating material 9. A thin film is grown while growing gases are supplied onto a substrate 4 from the central part of the above-mentioned parallel flat plate electrodes.

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] The present invention relates to a vapor phase growth method using an apparatus having a structure for reducing the generation of powdery precipitates. Plasma vapor deposition apparatus in which the entire surface of the lower electrode, including the peripheral edges of the electrode surfaces facing each other, is substantially flat, and the surface of the lower electrode is covered with a chemically stable insulating material except for the area of the facing electrode surfaces. 2. The method of plasma vapor phase epitaxy is characterized in that a thin film is grown while supplying a growth gas from the central portion of the parallel plate electrode onto the substrate. [Field of Industrial Application] The present invention relates to a plasma vapor deposition method for reducing powdery precipitates. Plasma CVD (ch
The electrical vapor deposition method is used for forming various films such as SiN and SiO ₂ necessary for manufacturing a semiconductor device because of its good controllability and excellent growth film characteristics. [Prior Art] In a conventionally used plasma CVD apparatus, an electrode for applying a high frequency has a shape in which all metal surfaces are exposed even when the electrode is placed in a reaction chamber. The main reason for this is that materials that react easily are not used in the parts that come into contact with the plasma gas, which is extremely active.However, as a result of the large exposed area of the metal surface, plasma is distributed almost throughout the reaction chamber. Will be done. [Problems to be Solved by the Invention] As described above, when plasma is distributed over almost the entire area of the reaction chamber, in the source gas supplied into the reaction chamber, the regions where the upper electrode and the lower electrode face each other, that is, on the substrate. Since the reaction product is generated by the plasma even in a region other than the region where the thin film is deposited, it becomes a powdery deposit and adheres to the wall surface of the reaction chamber. The powdery deposit adhered to the inner surface of the reaction chamber is easily separated from the wall surface, and if it falls on the substrate, it inhibits the film growth in that portion and causes pinholes. It is an object of the present invention to provide a plasma CVD apparatus that does not generate such undesirable powdery deposits. [Means for Solving the Problems] According to the present invention, the above-mentioned problem is to mount a growth substrate between an upper electrode and a lower electrode that are substantially flat over the entire surface including the peripheral edges of the electrode surfaces facing each other. In a plasma vapor phase growth apparatus having parallel plate type electrodes having a structure, and the surfaces of the upper and lower electrodes being covered with a chemically stable insulating material except for the areas of the facing electrode surfaces, a growth gas is used. Is supplied onto the substrate from within the surface of the opposing electrode surface, and a thin film is grown on the substrate. Further, the above method is performed, for example, by supplying the growth gas onto the substrate through a plurality of gas supply ports formed in the upper electrode. [Operation] As described above, the powdery precipitate is generated by the generation of plasma over almost the entire area of the reaction chamber. Therefore, if the region where the plasma is generated is limited to the region where the growth substrate is placed, that is, the facing portion of the upper electrode and the lower electrode, and the generation of the plasma from other electrode surfaces is limited, the powder The generation of particulate precipitates should be suppressed. In order to suppress the generation of plasma, that portion may be covered with an insulating material. However, even if such a configuration is adopted, plasma is generated by swelling laterally from the facing surface of the electrode, so the method of supplying the source gas is such that the source gas is supplied from the side facing the electrode. If so, by the time the source gas reaches the substrate,
The growth gas is consumed in the bulged portion, which causes generation of powdery precipitates. Therefore, in the present invention, as described above, the method of supplying the raw material gas onto the substrate from within the surface of the facing surface of the electrode is adopted. According to the method of the present invention, the source gas is directly supplied to the facing portion of the electrode where the discharge is performed, so that the source gas is suppressed from being first consumed in the region where the discharge that does not contribute to the growth occurs. . [Example] FIG. 1 shows a plasma vapor deposition apparatus in which the present invention is carried out. In FIG. 1, 1 is a reaction chamber, 2 is a lower electrode, 3 is an upper electrode, 4 is a semiconductor substrate, 5 is a heater, 6
Is an exhaust port, 7 is a high-frequency power source, 8 and 8'are plasma generating regions, 9 is an insulator coating, and 10 is a source gas supply port.
In the apparatus of FIG. 1, parallel plate type electrodes are provided in the reaction chamber 1, but the lower electrode 2 is formed so that a semiconductor substrate 4 can be placed on the upper surface thereof, and the lower electrode Is
It is configured to be heated by a heater 5 provided inside. The upper electrode 3 and the lower electrode 4 generate plasma by a high frequency voltage applied by a high frequency power supply 7. Further, in order to maintain the inside of the reaction chamber 1 at a low pressure of about 1 Torr, regular exhaust is performed through the exhaust port 6. Further, an insulating coating 9 made of, for example, quartz glass is coated on the electrode regions for generating unnecessary plasma, that is, on the upper and side surfaces of the upper electrode 3 and the side surfaces of the lower electrode 2. With this configuration, plasma is generated only in the region shown by the plasma generation head region 8 between the upper electrode 3 and the lower electrode 2. Further, in this embodiment, a method of directly supplying the source gas from the in-plane of the upper electrode 3 onto the semiconductor substrate 4 via the source gas supply port 10 is adopted. According to this method, the source gas is directly supplied to the semiconductor substrate 4, so that a region where a discharge that does not contribute to the growth is generated, that is, a plasma generation region 8 ′ on the side of the facing portion of the upper electrode 3 and the lower electrode 2 is formed first. The raw material gas is no longer consumed. Since the remaining gas consumed on the semiconductor substrate 4 flows into the lateral plasma generation region 8 ', the generation of extremely powdery precipitates is suppressed, and a high quality growth thin film without pinholes is formed. Obtainable. [Advantages of the Invention] As described above, according to the present invention, it is possible to reduce powdery deposits generated by plasma generated in an unnecessary portion, so that a good-quality grown thin film can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a plasma vapor phase growth apparatus of the present invention. In FIG. 1, 1 is a reaction chamber, 2 is a lower electrode, 3 is an upper electrode, 4 is a semiconductor substrate, 5 is a heater, 6 is an exhaust port, 7 is a high frequency power source, 8 and 8'is a plasma generation region, and 9 is The insulator coating 10 is a source gas supply port.

Claims (1)

Claims: (1) A parallel plate type electrode having a structure in which a growth substrate is mounted between an upper electrode and a lower electrode, the entire surface of which is substantially flat, including peripheral edges of electrode surfaces facing each other, And, in the plasma vapor phase growth apparatus in which the surfaces of the upper and lower electrodes are covered with a chemically stable insulating material except for the area of the facing electrode surface, the growth gas is applied from the inside of the facing electrode surface. A plasma vapor deposition method, comprising supplying on the substrate and growing a thin film on the substrate. (2) The plasma vapor deposition method according to claim 1, wherein the growth gas is supplied onto the substrate through a plurality of gas supply ports formed in the upper electrode.