JPS63176475A - Method for cleaning cvd device - Google Patents

Abstract

PURPOSE:To prevent the deposition of a reaction product on a substrate during the taking-out of the substrate and to simply clean the whole of a reaction chamber by feeding a rare gas into the chamber after the end of CVD and forming ions of the rare gas to sputter the surface of the wall of the chamber. CONSTITUTION:After the end of CVD of an SiO2 film or the like in a chamber 1, the feed of gaseous starting materials is stopped and a rare gas 12 such as Ar is fed into the chamber 1. Ions of the rare gas are formed by impressing negative voltage to the wall of the chamber 1 and positive voltage to an electrode 3 to sputter the surface of the wall of the chamber 1. Fine particles of SiO2 sticking to the surface of the wall are stripped off by the sputtering and gathered on the electrode 3 easy to take out. The particles dropped from the electrode 3 are accumulated on a plate 9. Thus, the deposition of fine particles on a substrate 2 kept at a high temp. immediately after the end of CVD can be prevented, so the quality of a formed film is not deteriorated.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a CVD equipment cleaning method.

[Conventional technology]

-m, CVD used in semiconductor device fabrication
In the device, reaction products adhere to parts other than the substrate. In particular, CV of 5i02 film etc. using silane gas
In the case of apparatus D, since the reaction products adhere to the wall surface in the form of fine particles, there are many troubles such as these peeling off and being deposited on the formed Si 02 film when the substrate is taken out after the completion of CVD.

The most typical method for reducing the adhesion of products to parts other than the substrate is to add nitrogen or the like to the window during photo-CVD in order to reduce the amount of film formed on the window material in a photo-CVD device. There is a method of blowing inert gas.

[Problem that the invention seeks to solve]

When using the above-mentioned method of blowing inert gas, it is possible to effectively reduce deposition on small areas such as windows, but in order to prevent deposition on the entire large wall surface, inert gas must be applied so that it spreads over the entire wall surface without any corners. You need to blow gas. In this case, the particles that have been prevented from being deposited are inevitably scattered throughout the chamber, so the particles are more likely to fall onto the substrate, resulting in unnecessary accumulation.

In this way, in the conventional CVD method, it is unavoidable that reaction products accumulate when the substrate is taken out from the wall surface, etc., and the effect can only be reduced by frequently cleaning the entire chamber. It also doesn't require a lot of man-hours.

SUMMARY OF THE INVENTION An object of the present invention is to provide a CVD method that eliminates the drawbacks of the conventional methods described above, prevents reaction products from accumulating when taking out a substrate, and facilitates cleaning of the entire chamber.

[Means for solving problems]

The CVD equipment cleaning method of the present invention is carried out by flowing a rare gas into the reaction chamber, applying a negative voltage to the wall surface of the reaction chamber, and applying a positive voltage to the electrode inside the reaction chamber after the completion of CVD. , forming ions of the rare gas, sputtering the wall surface of the reaction chamber with the rare gas ions, and cleaning the wall surface.

[Effect]

CV with particulate reaction products as a by-product of film formation
In chamber D, if a negative voltage is applied to the wall of the chamber to which the reaction products generated during CVD are attached, and a positive voltage is applied to the electrode that faces the wall and can be easily taken out from the chamber. , the Ar gas is discharged and becomes a plasma state, producing Ar+ ions and electrons. This Ar
The + ions collide at high speed with the reaction products in the form of particulates attached to the wall surface, which is the negative electrode, and perform a sputtering action, causing the reaction products to float from the wall surface. This floating reaction product adheres to the vicinity of the inner electrodes provided opposite to each other. In this way, the present invention uses sputtering by Ar+ ions to collect reaction products in the form of particulates at a specific location in the chamber, thereby preventing the particles from scattering and accumulating on the substrate when the substrate is taken out. I can do it.

[Embodiments of the invention]

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a schematic diagram showing a CVD apparatus to which an embodiment of the present invention is applied. The substrate 2 is connected to the heater 7 in the chamber 1.
is fixed on top. Raw material gas SiH4 gas 10 and N
20 gas 11 is supplied over the substrate 2 in a direction substantially parallel to the substrate 2.

, the inside of the second chamber 1 is evacuated by a rotary pump 6. S i H4 of raw material gas after CVD of SiO□ film
Gas 10. The N20 gas 11 is stopped, Ar gas 12 is supplied, and 15 kV is applied to the wall of the chamber 1 by the DC power source 4, and +5 kV is applied to the electrode 3 by the same DC power source 4.

The 5iO2 fine particles that do not adhere to the wall surface of the chamber 1 are sputtered by Ar'' ions and collected on the electrode 3, which can be easily taken out. Further, the Si02 fine particles that have fallen from the electrode 3 are collected on the plate 9.

The outside of the chamber 1 is surrounded by an insulator 5 to prevent the high voltage portion from being exposed. Further, the insulator 8 between the electrode heater terminals prevents discharge between the heater terminals and the electrodes.

In this example, 5iO2(ii
Particles cannot be collected in a specific location within the chamber where they can be easily removed. In addition, in the method according to this embodiment, most of the Si○2 fine particles attached to the wall surface are collected on the electrode 3, so it is possible to prevent them from accumulating on the substrate, which is still at a high temperature immediately after the CVD. , no deterioration of film quality occurs.

In addition, in the cleaning method according to this embodiment, 5iO
Since the work to remove the two fine particles is simply to replace each plate 9 of the electrode 3 with a clean one, the number of man-hours required for cleaning can be significantly reduced.

The present invention is not necessarily limited to CVD of SiO
N, insulating films such as Aj'203, C of semiconductor metals, etc.
It can also be applied to VD, and the configuration of the device in that case is completely the same as in the case of S i O2.

In the method according to the present invention, the inversion of ivy from the electrode to the wall surface was almost negligible and did not affect the cleaning of the chamber or the film quality.

[Effects of the Invention] As explained above, according to the present invention, by collecting the reaction products in the form of particulates attached to the wall surface of the CVD chamber by sputtering after completion of CVD at a specific location in the chamber from which they can be taken out, C. Deterioration of film quality due to accumulation of fine particles on the substrate is less likely to occur, and the number of man-hours required to clean the chamber for the next CVD can be reduced.
A method for cleaning a VD device can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a CVD apparatus illustrating an embodiment of the present invention. 1... Chamber, 2... Substrate, 3... Electrode, 4...
...DC power supply, 5...Insulator, 6...Rotary pump, 7...Heater, 8...Insulator between electrode heater terminals, 9...Plate, 10...5iHy gas, 11
...N20 gas, 12...Ar gas.

Claims (1)

[Claims] After the CVD is completed, ions of the rare gas are formed by flowing the rare gas into the reaction chamber, applying a negative voltage to the wall of the reaction chamber, and applying a positive voltage to the electrode inside the reaction chamber. A CV characterized by sputtering the wall surface of the reaction chamber with the rare gas ions and cleaning the wall surface.
D Equipment cleaning method.