JPH05226258A - Plasma generation apparatus - Google Patents

Abstract

PURPOSE:To obtain a plasma generation apparatus wherein it is small-sized, its efficiency is high and it causes no plasma damage. CONSTITUTION:A plurality of face-shaped electrodes 3 which have been arranged so as to be faced are installed inside a chamber 1. Out of the electrodes, the electrodes in an every other position are grouped as a first set and the remaining electrodes in every the other position are grouped as a second set. A high-frequency power supply 8 is connected across the electrodes in the first and second sets. A process gas is introduced into gaps formed by the electrodes. The electrodes may be constituted of concentric cylindrical electrodes. Since the large-area electrodes can be obtained by using small electrodes according to this structure, the sputtering phenomenon of the electrodes is not caused even when they are operated at high electric power. Since a plasma generation part is separated from a semiconductor substrate, no plasma damage is caused to the semiconductor substrate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high level activation technology of a process gas in a gas phase reaction technology such as a semiconductor manufacturing apparatus.

[0002]

2. Description of the Related Art In the gas phase etching process, ashing process, thin film deposition process and the like in semiconductor manufacturing technology, it is necessary to activate a necessary gas to a high concentration and to uniformly supply it to a semiconductor substrate. At this time, it is also necessary to prevent the semiconductor substrate from being damaged by the plasma.

For this purpose, conventionally, a parallel plate system as shown in FIG. 3, a barrel type system as shown in FIG. 4 and an ECR system as shown in FIG. 5 have been used. However, in the parallel plate type device as shown in FIG. 3, the surface of the semiconductor substrate is always exposed to the plasma, so that damage from the plasma becomes a problem. Further, when the applied power is increased to increase the amount of activated gas particles, there is a problem in that the electrode area is small, so that the power density is increased and damage to the substrate is increased.

In the barrel type apparatus as shown in FIG. 4, since the substrate is not directly exposed to the plasma due to the use of the etch tunnel, there is no damage from the plasma. , There was a problem of contamination on the substrate. Further, there is a problem in the uniformity of the supply of the activation gas to the large diameter substrate. Figure 5
Such an ECR type device is advantageous in terms of damage and uniformity, but there is a problem that the device becomes large and complicated, maintenance is troublesome, and the price of the device becomes expensive.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a plasma generator which is small in size, has high efficiency, and is free from plasma damage, by improving the drawbacks of the conventional device.

[0006]

According to the present invention, a plurality of planar electrodes are arranged to face each other in a vacuum chamber capable of maintaining a required degree of vacuum, and every other electrode constitutes a first set, and A second set of electrodes of every other electrode, a high frequency power source is connected between the electrodes of the first and second sets, and a process gas is introduced into the gap created by the electrodes. It is a generator.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a plasma generator according to the present invention. 2 (A) and 2 (B) are perspective views of the electrode structure, (A) is a parallel array of planar electrodes whose surfaces are passivated, and (B) is a similar cylindrical shape. The electrodes are arranged concentrically.

In FIG. 1, a plurality of flat electrode plates 3 are arranged in parallel in the upper part of the chamber 1 with a gap provided between adjacent electrode plates. The first set of electrodes is used, the other electrode is used as the second set of electrodes, and a high frequency power supply is connected between the first and second sets of electrodes. This electrode plate may be an odd number if it is two or more. A process gas introduction nozzle 2 is provided so that the process gas can flow into a gap provided between adjacent electrode plates. A substrate holder 4 is provided in the lower part of the chamber 1, and a semiconductor substrate 5 is placed on the substrate holder 4, and the lower part of the substrate holder 4 is cooled (heated).
There is a device. Further, the chamber 1 is provided with an exhaust port 7 for removing waste gas.

According to the present invention, in the above configuration, the process gas is mixed in an appropriate amount according to the process used, and then the nozzle 2 is used.
It is emitted into the gap formed by the electrode plate 3 and is turned into plasma by the electric power supplied from the high frequency power source and excited. After the excited process gas passes through the gap between the electrode plates 3, the semiconductor substrate 5 mounted on the substrate holder 4
And a chemical reaction occurs on the substrate surface.

The substrate holder 4 is provided with a cooling (or heating depending on the process) device 6 for maintaining the best reaction state. Waste gas generated by this reaction is removed from the exhaust port 7. Although the planar electrode structure has been described above, as another embodiment of the present invention, FIG.
It is apparent that the same effect can be obtained also in the electrode in which the cylindrical ones are concentrically arranged as shown in (B).

[0011]

As described above, according to the present invention, since a large electrode having a small electrode can be obtained as described above, the entire plasma generator can be miniaturized. Even if the amount of electric power is increased to increase the amount of active species (excited species) generated, the electrode area is large, so the power density on the electrode surface does not increase so much and the electrode sputtering phenomenon does not occur, thus contaminating the semiconductor substrate Never.

Since the plasma generating portion and the substrate are separated, there is no plasma damage to the semiconductor substrate. Further, the present invention has a simple device structure, which facilitates maintenance.
The manufacturing cost is low, and it is easy to cope with the future increase in the area of the semiconductor substrate.

[Brief description of drawings]

FIG. 1 is a sectional view of a plasma generator according to the present invention.

2A and 2B are perspective views of electrodes used in the present invention.

FIG. 3 Conventional plasma generator

FIG. 4 Conventional plasma generator

FIG. 5: Conventional plasma generator

[Explanation of symbols]

 1 Chamber 2 Nozzle 3 Electrode Plate 4 Holder 5 Semiconductor Substrate 6 Cooling (Heating) Device 7 Exhaust Port 8 High Frequency Power Supply

Claims (3)

[Claims] 1. A vacuum chamber capable of maintaining a required degree of vacuum, a plurality of planar electrodes arranged to face each other in the chamber, and every other electrode of the electrodes constitutes a first set, and Every other electrode is used as the second set, and the first set and the second set.
And a means for introducing a process gas into a gap formed by the electrodes, and a high frequency power source connected between electrodes of the pair. 2. The plasma generator according to claim 1, wherein the electrodes are planar electrodes arranged in parallel. 3. The plasma generator according to claim 1, wherein the electrodes are cylindrical electrodes arranged concentrically.