JPH02250314A - Plasma cvd apparatus - Google Patents

Abstract

PURPOSE:To prevent a foreign substance from being produced outside a heating container by a method wherein the heating container capable of housing an object to be treated at its inside is provided between electrodes for plasma generation use, a gas-outflow port and an introduction port of a reaction gas are installed at the heating container and a gas-supply passage linked to the gas-introduction port is installed at the electrode on one side. CONSTITUTION:A gas-outflow port 21 is installed at a heating container 19 which has been installed between electrodes 14, 15 for plasma generation use; introduction ports 22 of a reaction gas are installed; a gas-supply passage 17 linked to the gas-introduction ports 22 installed at the electrode on one side. A pressure inside a vacuum container 11 is reduced to 10<6>Torr; a pressure inside the heating container 19 is reduced to 10<1> to 10Torr; the reaction gas is introduced; a high-frequency voltage is applied to the electrodes 14, 15. A plasma 19 is generated inside the heating container 19; the reaction gas is pyrolyzed and reacts on a substrate 20. An undecomposed reaction gas is discharged to the outside of the heating container 19 from the gas-outflow port 21 ; it is diluted with an inert gas which has been introduced from an introduction port 12; its gas density is reduced; accordingly, it is possible to substantially neglect that a foreign substance is produced outside the heating container 19. Thereby, it is possible to restrain a plasma from being generated and to prevent the foreign substance from being produced outside the heating chamber.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a plasma CVD apparatus suitable for use in the manufacturing process of electronic devices such as semiconductor integrated circuits.

[Conventional technology]

In general, plasma CVD equipment has been widely adopted because it is capable of forming thin films at low temperatures, and
d 5tate Technol-Vol, 19.45
(1976) and is configured as shown in FIG. To explain this based on the figure, in the figure, the reference numeral 1 denotes a vacuum vessel having a gas outlet 2 connected to a vacuum pump (not shown), and 3 and 4 are provided inside the vacuum vessel 1. There are two upper and lower electrodes facing each other, and 5 is a high frequency power source for plasma generation connected to these electrodes 3 and 4 and provided outside the vacuum vessel 1. Further, reference numeral 6 denotes a heater that is provided outside the vacuum chamber 1 and heats the object to be processed (hereinafter referred to as a substrate) 7 on the lower electrode 4 of the picture electrodes 3.4. Note that 8 is a gas supply passage provided in the lower electrode 4 and communicating with the inside of the vacuum container 1.

To form a thin film using the plasma CVD apparatus configured in this way, first, the substrate 7 is placed on the lower electrode 4, and then the inside of the vacuum vessel 1 is reduced to a predetermined pressure, and then the gas supply passage 8 is After introducing the reaction gas into the vacuum container l, the picture electrode 3
, 4 by applying a high frequency voltage between them. At this time, since plasma is generated in the vacuum container l, the reaction gas is thermally decomposed and becomes active species, which form the group +JM?
React above.

[Problem to be solved by the invention]

By the way, in a conventional plasma CVD apparatus, the pressure inside the vacuum chamber 1 is set to approximately the same pressure at any point, and therefore, when forming a thin film, plasma is generated throughout the vacuum chamber 1 and the substrate 7 is heated. The product adhered not only to the above 6 but also to other parts, making it necessary to frequently clean the inside of the vacuum container 1.

That is, in a low-temperature atmosphere where plasma is generated, the products adhering to the inside of the vacuum container l tend to peel off, and if this adheres as foreign matter on the substrate 7 during thin film formation, it will adversely affect the thin film formation. be. As a result, the number of repetitions of starting and stopping increases, resulting in a problem that the productivity of the device decreases.

The present invention was made in view of these circumstances, and it is possible to reduce the number of repetitions of starting and stopping, thereby increasing the productivity of the device.
It provides a VD device.

[Means to solve the problem]

A plasma CVD apparatus according to the present invention includes a vacuum container having a gas exhaust port, two plasma generation electrodes provided in the vacuum container and facing each other, and a plasma CVD device provided between the two plasma generation electrodes and provided inside the vacuum container. The heating container is provided with a gas outlet that communicates with the inside of the vacuum container, and a gas inlet that introduces a reaction gas, and a gas inlet that communicates with the gas inlet is provided in the heating container. A supply passage is provided in one of the two plasma generation electrodes.

[For production]

In the present invention, it is possible to improve the adhesion of the product inside the heating container during thin film formation, and it is also possible to suppress the generation of plasma outside the heating container and prevent the generation of foreign matter.

〔Example〕

EMBODIMENT OF THE INVENTION Hereinafter, the structure etc. of this invention will be explained in detail by the Example shown in the figure.

FIG. 1 is a sectional view showing a plasma CVD apparatus according to the present invention. In the same figure, the reference numeral 11 is a vacuum container for CVD thin film formation, and the upper part is provided with a purge gas inlet 12 for adjusting the pressure inside the container, and the lower part is connected to a vacuum pump (not shown). A gas exhaust port 13 is provided to allow the gas to flow. Reference numerals 14 and 15 are two plasma generating electrodes facing each other at a predetermined distance, and are provided within the vacuum vessel 11 and connected to a power source 16 serving as a high frequency oscillator. Of these two electrodes 13 and 14, the upper electrode 14 has a gas supply passage 17 for supplying a reaction gas.
is provided, and the lower electrode 15 has a built-in heater 1B that heats a reaction container, which will be described later. Reference numeral 19 denotes a reaction vessel as a heating vessel, which includes a bottomed cylinder 19a that can accommodate a substrate (workpiece) 20 therein, and a lid 19b that closes the opening of this bottomed cylinder 19a.
．． It is located between 15 and 15. A gas outlet 21 communicating with the vacuum vessel 11 is provided on the side of the reaction vessel 19, and a gas inlet (nozzle) 22 communicating with the gas supply passage 17 is provided at the top. .

Thin film formation using the plasma CVD apparatus configured as described above is performed through the following steps. That is, first, the substrate 20 is housed in the reaction container 19, and then the pressure inside the vacuum container 11 is reduced to a predetermined pressure of 10'Toor, and after the pressure inside the reaction container 19 is reduced to a pressure in the range of 10' to 10Toor, After introducing a reaction gas into this reaction vessel 19, a high frequency voltage is applied between both electrodes 14 and 15. At this time, since plasma is generated in the reaction vessel 19, the reaction gas is thermally decomposed to become active species, which react on the substrate 20.

Here, since the pressure outside the reaction vessel 19 inside the vacuum vessel 11 is set to a pressure of 10'Toor or less,
Plasma generation can be suppressed in this region, and part of the undecomposed reaction gas and active species flow out of the reaction vessel 19 from the gas outlet 21 and expand rapidly, and at the same time It is diluted by the introduced inert gas and the gas density becomes small. Therefore, when forming a thin film, the generation of foreign matter inside the vacuum vessel 11 and outside the reaction vessel 19 can be substantially ignored. When the temperature inside the reaction vessel 19 is set to about 200° C., the adhesion of the product (thin film) inside the reaction vessel 19 becomes good.

Note that the gas inlet 22 and gas outlet 21 in the present invention
The shape of the inert gas, the flow rate of the inert gas, and the evacuation speed inside the vacuum container 11 by a vacuum pump (not shown) can be changed as appropriate.

〔Effect of the invention〕

As explained above, according to the present invention, there is a vacuum container having a gas exhaust port, two plasma generation electrodes provided in the vacuum container and facing each other, and a plasma generation electrode provided between the two plasma generation electrodes. The heating container is provided with a gas outlet that communicates with the inside of the vacuum container, and a gas inlet for introducing a reaction gas is provided in the heating container, which communicates with the gas inlet. Since a gas supply passage that communicates with one of the two plasma generation electrodes is provided, plasma generation outside the heating container can be suppressed during thin film formation.
This makes it possible to prevent the generation of foreign matter, and also to improve the adhesion of the product inside the heating container.

Therefore, it is possible to reduce the number of times the device is repeatedly operated and stopped due to cleaning, thereby increasing the productivity of the device.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a plasma CVD apparatus according to the present invention, and FIG. 2 is a sectional view showing a conventional plasma CVD apparatus. 11... Vacuum container, 13... Gas outlet, 14
, 15... electrode, 18... heater, 19...
- Reaction container, 20... substrate, 21... gas outlet, 22... gas inlet. Agent Masuo Oiwa

Claims (1)

[Claims] A vacuum container having a gas exhaust port, two plasma generation electrodes provided in the vacuum container and facing each other, and a heating device provided between these plasma generation electrodes and capable of accommodating the object to be processed therein. a container, the heating container is provided with a gas outlet communicating with the inside of the vacuum container, a gas inlet for introducing a reaction gas is provided, and a gas supply passage communicating with the gas inlet is provided for both plasma generation. Plasma C characterized in that it is provided on one of the electrodes.
VD device.