JPS63262473A - Plasma cvd device - Google Patents

Abstract

PURPOSE:To surely remove the impurities on the surface of a substrate in a short time in a spare chamber by introducing a gas not affecting film formation into the spare chamber to generate and electric discharge, and imparting ion bombardment to the substrate surface. CONSTITUTION:The substrate 5 is set in the spare chamber 1, and a gate valve 4a is closed. The inside of the spare chamber 1 is evacuated, and the gas not adversly affecting film formation such as hydrogen and an inert gas is introduced. A high-frequency power is supplied to a high-frequency electrode 6a from a high-frequency source 7a, and the ion and electron in the plasma produced by the electric discharge are allowed to collide on the substrate 5 with the energy accelerated by the high-frequency electric field and the electric field in a sheath. At this time, a part of the neutral corpuscules are also allowed to collide with the substrate 5. As a result, the impurities adsorbed on the surface of the substrate 5 are splashed, and the surface of the substrate 5 is cleaned. The cleaned substrate 5 is transported to a film forming chamber 2, and a film is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a plasma CVD apparatus, and particularly to a cleaning technique for a substrate to be subjected to film formation.

[Conventional technology]

A typical example of a conventional plasma CVD apparatus will be explained with reference to FIG.

FIG. 5 is a schematic diagram for explaining an example of a conventional plasma CVD apparatus. In this figure, 1 is a preliminary chamber where the substrate surface is cleaned, 2 is a film forming chamber where a desired thin film is formed on the substrate surface, and 3a and 3b are substrate heating units provided in the preliminary chamber 1 and the film forming chamber 2, respectively. 4a is the heater for the preliminary chamber 1.
4b is a gate valve provided between the preliminary chamber 1 and the film forming chamber 2, 5 is a substrate placed in the film forming chamber 2, 6 is a high frequency electrode, 7 is a substrate side electrode, It is arranged opposite to the high frequency electrode 6. 8 is a high frequency power supply, and 9 is a matching network.

In order to mount the substrate 5 in the film forming chamber 2 in the illustrated state, first close the gate valve 4b, open the gate valve 4a, set the preliminary chamber 1 to atmospheric pressure, and mount the substrate 5 there.
The gate valve 4a is closed and the preliminary chamber 1 is evacuated to vacuum.

After the preliminary chamber 1 is sufficiently evacuated, the substrate 5 is preheated by the heater 3a. After that, the gate valve 4b
, and transfer the substrate 5 to the film forming chamber 2 using a substrate transport means (not shown).
, and close the gate valve 4b. The figure shows the state after the substrate 5 is installed in the film forming chamber 2. By going through the above steps, it is possible to mount the substrate 5 in the film forming chamber 2 without exposing the film forming chamber 2 to the atmosphere. Further, by performing preheating in the preparatory chamber 1, impurities adsorbed on the surface of the substrate 5 in the atmosphere can be removed.

Next, high-frequency power from the high-frequency power source 8 is applied to the high-frequency electrode 6 to cause discharge, decomposing the raw material gas, and depositing a desired film on the substrate 5.

(Problems to be Solved by the Invention) Since the conventional plasma CVD apparatus is configured as described above, the preliminary chamber 1 can only preheat the substrate 5;
There are problems in that it takes a long time to remove impurities adsorbed on the substrate 5 in the atmosphere, and impurities cannot be completely removed.

This invention was made to solve the above-mentioned problems, and allows impurities to be removed in a short time in a preliminary chamber.
The object of the present invention is to obtain a plasma CVD apparatus that can perform reliably.

(Means for Solving the Problems) The plasma CVD apparatus according to the present invention has a film forming chamber for forming a desired thin film on the surface of a substrate by plasma discharge, and a film forming chamber that is independently evacuated to form a film. Plasma CVD equipped with a preliminary chamber for cleaning the surface of the substrate transferred to the chamber
The apparatus is equipped with plasma generating means for introducing a gas that does not affect film formation into a preliminary chamber and generating plasma from this gas to clean the substrate surface.

[Function] Since the plasma CVD apparatus according to the present invention is equipped with a plasma generation means in the preparatory chamber, a gas that does not affect film formation is introduced into the preparatory chamber and discharge is performed, thereby generating ions on the substrate surface. Impact is applied to remove impurities from the substrate surface.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram of a plasma CVD apparatus showing an embodiment of the present invention. In this figure, the same numerals as in Fig. 5 indicate the same things, but in the following, the numerals corresponding to the preliminary chamber 1 side will be affixed a, and the numerals corresponding to the film forming chamber 2 side will be affixed b as necessary. I decided to do it.

In order to attach the substrate 5 to the film forming chamber 2 as shown in FIG.
First, the gate valve 4b is closed, the gate valve 4a is opened, the preliminary chamber 1 is set to atmospheric pressure, and the substrate 5 is mounted therein.
Close the gate valve 4a. After the preliminary chamber 1 is sufficiently evacuated, the substrate 5 is heated by the heater 3a, a gas such as hydrogen or an inert gas that does not adversely affect the film formation is introduced, and high-frequency power from the high-frequency power source 7a is applied. It is supplied to the high frequency electrode 6a to cause discharge. At this time, the substrate 5 is at ground potential. Ions and electrons in the plasma generated by the discharge are accelerated by the high frequency electric field and the electric field within the sheath, gain energy, and collide with the substrate 5. Also,
Some of the neutral particles in the plasma also gain energy through collision with high-speed ions and collide with the substrate 5. When these particles in the plasma collide with the substrate 5, impurities adsorbed on the surface of the substrate 5 are splashed, thereby purifying the surface of the substrate. In this way, due to the effect of particle collisions in the plasma,
It is also possible to remove impurities with large separation energy that cannot be removed by heating alone.

At this time, if an element having a large atomic number and mass, such as argon, is used as the introduced gas, it will give a large amount of energy when it collides with the substrate 5, and the purifying effect will be large. Furthermore, if the area ratio of the high-frequency electrode 6a and the area of the substrate 5 in contact with the plasma is made smaller on the substrate 5 side, that is, on the ground electrode side, the sheath voltage will be larger on the substrate 5 side, and the ions will be The energy obtained when accelerated increases, and the purification effect thereby increases.

After cleaning the surface of the substrate 5 as described above, the gate valve 4b is opened and the substrate 5 is transported to the film forming chamber 2 by a substrate transport means (not shown).
Close the door and perform film formation.

In the above embodiment, as a method of supplying high-frequency power to the preliminary chamber 1, a structure was shown in which the substrate 5 side was set to the ground potential and the high-frequency electrode 6a was provided opposite to this, but as shown in FIG. , a structure in which high-frequency power is supplied to the substrate 5 side and the opposing electrode 7a is set to the ground potential may be used. In the case of this structure, it is easy to configure the ratio of the areas in contact with plasma between the substrate 5 and the electrode 7a facing thereto to be smaller on the substrate 5 side. Furthermore, as shown in FIG. 3, if a DC bias voltage is applied to the substrate 5 by the DC power supply 10 so that the potential becomes negative from the ground potential, the sheath potential on the surface of the substrate 5 increases and the ion bombardment becomes stronger. , the cleaning effect is increased. Furthermore, as shown in FIG. 4, a magnetic field coil 11 is used as a plasma generating means for generating plasma in the preliminary chamber.
A similar effect can be obtained by using the magnetic field from the microwave power source 12 and electron cyclotron resonance caused by microwaves.

〔Effect of the invention〕

As explained above, the present invention includes a film forming chamber in which a desired thin film is formed on the surface of a substrate by plasma discharge, and a film forming chamber that is independently evacuated to form a thin film on the surface of a substrate that is moved to the film forming chamber. A plasma CVD apparatus equipped with a preliminary chamber for performing a cleaning process, which includes plasma generating means for introducing a gas that does not affect film formation into the preliminary chamber and generating plasma of this gas to clean the surface of a substrate. Therefore, the substrate can be discharge cleaned in the preliminary chamber. Therefore, it is possible to efficiently remove impurities with large separation energy that cannot be removed by heating alone in a short time.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a schematic configuration of one embodiment of a plasma CVD apparatus of the present invention, FIGS. 2 to 4 are schematic diagrams showing other embodiments of the invention, and FIG. FIG. 1 is a schematic diagram showing an example of a CVD apparatus. In the figure, 1 is a preliminary chamber, 2 is a film forming chamber, and 3a. 3b is a heater for heating the substrate, 4a and 4b are gate valves,
5 is a substrate, 6a, 6b are high frequency electrodes, 7a, 7b are high frequency power supplies, 8a, 8b are matching networks, 10
1 is a DC power source, 11 is a magnetic field coil, and 12 is a microwave power source. Note that the same reference numerals in each figure indicate the same or corresponding parts. Agent Masuo Oiwa (2 others) Nogu Φ Figure 3 Figure 4 Figure 5 Procedure amendment (voluntary)

Claims (6)

[Claims] (1) A film forming chamber that forms a desired thin film on the surface of a substrate by plasma discharge, and a reserve that is independently evacuated from this film forming chamber and performs a cleaning process on the surface of the substrate transferred to the film forming chamber. A plasma CVD apparatus comprising a plasma CVD chamber, characterized in that the plasma CVD apparatus includes a plasma generating means for introducing a gas that does not affect film formation into the preparatory chamber to generate plasma and cleaning the substrate surface. Plasma CVD equipment. (2) The plasma CVD apparatus according to claim (1), wherein the plasma generation means in the preparatory chamber is based on high-frequency discharge by applying high-frequency power to a high-frequency electrode placed opposite to the substrate. (3) The plasma CVD apparatus according to claim (1), wherein the plasma generating means in the preparatory chamber is based on high-frequency discharge by applying high-frequency power to the substrate. (4) The plasma CVD apparatus according to claim (1), wherein a DC bias voltage is applied to the substrate in the preliminary chamber. (5) An electrode structure in which the area of the substrate-side electrode in contact with the plasma is smaller than the area of the high-frequency electrode placed opposite to the substrate in contact with the plasma. The plasma CVD apparatus according to any one of item (4). (6) The plasma generating means is a plasma C according to claim (1), which uses electron cyclotron resonance.
VD device.