JPH04228573A - Method for reducing particulate contamination in plasma chemical vapor deposition device - Google Patents

Abstract

PURPOSE:To prevent the surface of a substrate from being contaminated with dust in a plasma chemical vapor deposition device by charging and discharging a gas to and from a vacuum vessel plural times before the substrate is set in the vessel. CONSTITUTION:A vacuum vessel 1 is firstly evacuated to a high vacuum by a vacuum pump 10, and a counter electrode 2 on which a substrate 3 has not been set is moved and opposed to a discharge electrode 4 (the substrate 3 is not set). A gas feed valve 5 is opened for a specified time to introduce a gas into the vessel 1. The valve 5 is then closed for a definite time to evacuate the vessel 1, and the process is repeated several times. When the gas is introduced into the vessel 1 with the electrode 2 being set, the dust on the electrode 4 surface, etc., is whirled up. However, the dust floating in the vessel 1 is discharged outside the vessel from an exhaust port by stopping the supply of the gas. The process is repeated several times before deposition, and the contamination of the substrate 3 surface with dust is reduced during the deposition.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for optimizing the vacuum phase condition before deposition in a vacuum deposition apparatus such as a parallel plate type plasma chemical vapor deposition apparatus.

0002

2. Description of the Related Art A conventional parallel plate type plasma chemical deposition apparatus has the structure shown in FIG.
The inside of the vacuum chamber 1 is evacuated to a high vacuum. At this time, since the gas supply valve 5 is closed, no gas is introduced through the discharge electrode 4 having a large number of holes.

0003

[Problems to be Solved by the Invention] By the way, when gas is introduced after the inside of the vacuum chamber 1 is evacuated to a high vacuum, fine particles existing on the surface of the discharge electrode 4 are kicked up, and further There is a problem in that the surface of the substrate 3 attached to the counter electrode 2 located at the opposing position is contaminated with fine particles and the like, resulting in deterioration of characteristics and an increase in the occurrence of defects.

The present invention solves the above problems and aims to provide a means for reducing contamination by particulates within a vacuum chamber.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention makes introduction and exhaust into the vacuum chamber one cycle, and the above-mentioned process is repeated at least multiple times before setting the substrate in the vacuum chamber. This is a method for reducing particulate contamination in plasma chemical vapor deposition equipment that repeats cycles.

[0006]

[Operation] By the method described above, the present invention can reduce the accumulation of dust such as fine particles in the vacuum chamber due to repeated deposition processes, and can prevent contamination of the substrate surface by dust.

[0007]

[Embodiment] An embodiment of the present invention will be described below. In addition,
The configuration of the plasma chemical vapor deposition apparatus is the same as that shown in the conventional example, and a description of the configuration will be omitted.

The feature of the embodiment of the present invention lies in its operating method. (1) Initially, the gas introduction valve 5 shown in FIG. It is maintained. (2) Move the dummy tray (counter electrode: hereinafter referred to as tray) 2 without setting the substrate 3 to face the discharge electrode 4 in a high vacuum state. (Substrate 3 is not set) ■ Open the gas introduction valve for a certain period of time to introduce gas into the vacuum chamber 1. ■ Close the gas introduction valve for a certain period of time to exhaust the inside of the vacuum chamber 1. ■Above■〜
Repeat ■ several times. ■Take out the dummy tray 2 from the vacuum chamber 1.

[0009] When gas is introduced into the vacuum chamber 1 with the dummy tray 2 set therein, the dust existing on the surface and inside of the discharge electrode 4 will fly up into the vacuum chamber 1 with great force. However, since the upper part is covered by the dummy tray 2, the dust does not spread more than necessary. next,
By stopping the gas introduction and performing exhaust, the dust floating in the vacuum chamber 1 is discharged to the outside of the vacuum chamber 1 through the exhaust port.

[0010] By performing this operation before deposition,
Contamination by dust on the surface of the substrate 3 during deposition can be reduced. FIG. 2 shows the change in the number of dust particles with a diameter of 0.28 μm or more in the vacuum chamber 1 when the means of the present invention is used. This figure shows that by using the means of the present invention, the number of dust particles accumulated in the vacuum chamber 1 before deposition is reduced to about one-fifth.

[0011]

[Effects of the Invention] As described above, the present invention discharges dust accumulated on discharge electrodes etc. by intermittently introducing and exhausting gas into a vacuum chamber during continuous deposition processing. This has the effect of preventing dust from contaminating the substrate surface.

Although a parallel plate type plasma chemical vapor deposition apparatus has been described as an embodiment of the present invention, the present invention does not impair its effects on other vacuum deposition apparatuses.

[Brief explanation of the drawing]

[Figure 1] Longitudinal cross-sectional view of a cross-sectional view of a parallel plate type plasma chemical vapor deposition device

[Fig. 2] Characteristic diagram showing the number of dust deposits on a 5-inch round silicon substrate when using the means of the present invention as measured by a laser dust counter.

[Explanation of symbols]

1 Vacuum chamber 3　　　　　Substrate 5 Gas supply valve 6 Gas supply source 9 Gas exhaust valve 10 Exhaust pump

Claims (1)

[Claims] 1. Reduction of particulate contamination in a plasma chemical vapor deposition apparatus in which the introduction and exhaust of gas into a vacuum chamber is one cycle, and the above cycle is repeated at least multiple times before setting a substrate in the vacuum chamber. Method.