JPH0869969A - Plasma cvd device - Google Patents

Abstract

PURPOSE: To cut down the maintenance time while rapidly lowering the temperature within the title plasma CVD device wherein electrodes mounting a substrate are provided with a heater. CONSTITUTION: This invention is related to the title CVD device wherein high-frequency power is supplied between upper and lower electrodes to produce plasma for processing a substrate to be processed. Accordingly, plural numbers of reflection plates 9 are provided beneath a lower electrode 8 provided with a heater while at least the reflection plate on the topmost position out of the total reflection plates 9 are hollow-structured to bore a dispersion hole 15, on the other hand, cooling gas feed pipe 16 is communicated with the reflection plates 9 for enabling the cooling gas to run out of the dispersion hole 15 while in the maintenance time of this plasma CVD device, the cooling gas is dispersedly run in through the intermediary of the dispersion hole 15 from the cooling gas feed pipe 16 so as to rapidly cool down the lower electrode and the reflection plates 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma CVD apparatus, and more particularly to improvement of the electrode structure of the plasma CVD apparatus.

[0002]

2. Description of the Related Art As one of semiconductor manufacturing apparatuses, a substrate to be processed is placed in a sealed space, a reaction gas is supplied to the sealed space, and high frequency power is applied to an electrode facing the substrate to be processed. There is a plasma CVD apparatus for generating plasma to form a thin film on the substrate to be processed or for etching the thin film.

A conventional plasma CVD apparatus will be described with reference to FIG.

An upper electrode 2 is provided on the ceiling surface of the vacuum container 1 via an insulator 3, an inner tank wall 4 surrounding the upper electrode 2 is provided on the ceiling surface, and a lower end of the inner tank wall 4 is provided. The susceptor 6 on which the substrate 5 to be processed is placed can be in close contact, and the space surrounded by the upper electrode 2, the inner tank wall 4 and the susceptor 6 forms the reaction chamber 7. The reaction gas is introduced into the reaction chamber 7 through a reaction gas introduction passage (not shown) provided in the upper electrode 2, and the gas discharged from the reaction chamber 7 is introduced into the vacuum container 1 outside the vacuum container 1. An exhaust system (not shown) for exhausting is communicated.

The susceptor 6 is mounted on the lower electrode 8, and a plurality of layers of reflecting plates 9 are provided below the lower electrode 8. A heater (not shown) is embedded in the lower electrode 8,
The heater uses the susceptor 6 at 350 ° C. which is suitable for the film forming temperature
Keep heating back and forth. The lower electrode 8 is provided on an elevating substrate 10, and the elevating substrate 10 is fixed to the upper end of an elevating rod 11 that penetrates the bottom surface of the vacuum container 1 in an airtight manner and so as to elevate. A connecting plate 12 is fixed to the lower end of the elevating rod 11, and the elevating rod 11 is connected to the elevating cylinder 13 via the connecting plate 12.

Incidentally, reference numeral 14 in the drawing denotes a carrying port for carrying in and carrying out the substrate.

When processing the substrate 5 to be processed in the plasma CVD apparatus, the lower electrode 8 is lowered from the lifting cylinder 13 via the lifting rod 11 and the lifting substrate 10 to open the reaction chamber 7, The substrate 5 to be processed is placed on the susceptor 6 from the transfer port 14 by a transfer device (not shown).

The lower cylinder 8 is driven by driving the lifting cylinder 13.
And the susceptor 6 is brought into close contact with the inner tank wall 4.
The reaction gas is introduced into the reaction chamber 7 through the reaction gas introduction path of the upper electrode 2.
Then, high frequency power is supplied to the upper electrode 2 to generate plasma in the reaction chamber 7 to form a thin film on the substrate 5 to be processed. In this thin film forming process, the susceptor 6 is heated to about 350 ° C. by the heater embedded in the lower electrode 8. The reflection plate 9 blocks radiant heat from the upper electrode 2 downward.

When the film-forming process is performed on the substrate 5 to be processed in the above-described plasma CVD apparatus, reaction by-products adhere to and deposit on the wall surface of the reaction chamber 7. When the deposits are separated, they become particles and contaminate the substrate 5 to be processed in the reaction chamber 7. Therefore, the reaction chamber 7 is cleaned regularly or at every predetermined operating time.

[0010]

When performing maintenance work such as the cleaning work described above, it is necessary to lower the temperature of the lower electrode 8 and the reflection plate 9 to around 50 ° C. The temperature was lowered only by convection. Therefore, the heat removal effect on the lower electrode 8 and the reflection plate 9 was low, and the temperature reduction took a long time. The time required for such maintenance has a great influence on the operating rate, which hinders the improvement of the operating rate in the conventional plasma CVD apparatus.

In view of the above situation, the present invention intends to reduce the temperature quickly and shorten the maintenance time.

[0012]

DISCLOSURE OF THE INVENTION The present invention is a plasma CVD apparatus for processing a substrate to be processed by supplying high frequency power between upper and lower electrodes to generate a plasma, and a lower electrode provided with a heater. A plurality of reflecting plates are provided below, at least the uppermost reflecting plate of the reflecting plates has a hollow structure, a dispersion hole is formed on the upper surface of the reflecting plate, and a cooling gas supply pipe is connected to the reflecting plate. The cooling gas can flow out through the dispersion holes.

[0013]

During maintenance of the plasma CVD apparatus, the cooling gas is dispersed and introduced from the dispersion holes of the reflection plate through the cooling gas supply pipe to rapidly cool the lower electrode and the reflection plate.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

1 to 2, the same parts as those shown in FIG. 3 are designated by the same reference numerals.

The uppermost cooling plate 9 of the plurality of layers is hollow, a large number of dispersion holes 15 are formed in the upper surface of the reflecting plate 9, and a cooling gas supply pipe 16 is connected to the reflecting plate 9. The cooling gas supply pipe 16 penetrates the bottom plate of the vacuum container 1 in an airtight manner, and a bellows 17 is provided between the bottom plate and the elevating substrate 10 so as to follow the elevating and lowering of the reflecting plate 9.
The cooling gas supply pipe 16 is connected to a cooling gas source (not shown), and a stop valve 18 is provided on the way.

The dispersion holes 15 may be formed in a matrix form uniformly over the entire surface of the reflection plate 9 as shown in FIG. The distribution ratio of the dispersion holes 15 may be changed.

In the above embodiment, the processing of the substrate 5 to be processed is performed in the same manner as in the conventional example described above with the stop valve 18 closed.

Next, when cooling the lower electrode 8 and the reflecting plate 9 during maintenance, the stop valve 18 is opened to introduce the cooling gas from the cooling gas source (not shown) to the reflecting plate 9, and the cooling gas is supplied from the dispersion holes 15 to the cooling gas. Drain. The cooling gas flows along the lower surface of the lower electrode 8, the heat of the reflection plate 9 and the lower electrode 8 is positively removed, and effective and rapid temperature reduction is realized.

Here, the cooling gas is nitrogen gas,
An inert gas such as argon gas or helium gas is used.

[0021]

As described above, according to the present invention, since the reflecting plate located below the lower electrode is provided with the dispersion holes so that the cooling gas flows out from the reflecting plate, the gap between the cooling gas and the lower electrode is reduced. The heat exchange is promoted, the temperature lowering rate of the lower electrode and the reflection plate can be shortened, the maintenance time can be shortened, and the productivity can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a perspective explanatory view of a reflection plate in the embodiment.

FIG. 3 is a cross-sectional view showing a conventional example.

[Explanation of symbols]

 2 upper electrode 5 processed substrate 6 susceptor 7 reaction chamber 8 lower electrode 9 reflector 15 dispersion hole 16 cooling gas supply pipe 17 bellows 18 stop valve

Claims (1)

[Claims] 1. A plasma CV for processing a substrate to be processed by supplying high frequency power between upper and lower electrodes to generate plasma.
In the D device, a plurality of reflectors are provided below the lower electrode provided with the heater, at least the uppermost reflector of the reflectors has a hollow structure, and dispersion holes are formed on the upper surface of the reflector. A cooling gas supply pipe is connected to the reflection plate so that the cooling gas can flow out from the dispersion holes.