JPS583635A - Apparatus for carrying out chemical vapor growth in plasma - Google Patents

Abstract

PURPOSE:To cause a growth of a film with good quality at a high film growing speed, by a method wherein a third electrode is placed between two opposed electrodes and high frequency voltage is applied between two electrodes and voltage negative to reference potential to the third electrode. CONSTITUTION:An upper electrode 11 and a lower electrode 12 are opposed apart in a reaction chamber 10 to be connected reference potential as well as third electrode 17 for placing a base plate heated by a heater 21 but insulated from the lower electrode 12 is provided on said lower electrode 12. In this condition, high frequency voltage is applied between the upper and the lower electrodes 11, 12 as well as voltage negative to reference potential to the third electrode 17. By this method, plasma can be concentrated to the vicinity of the base plate 21 and, therefore, a grown film having enhanced film quality is obtained at a high film growing speed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the above-mentioned substrate K by concentrating plasma between an electrode on which the substrate is placed and an electrode opposite thereto.

In the conventional apparatus of this kind, as shown in FIG. 1, the GLAZE! A generation electrode 2.3 is arranged, and its upper electrode 2tj is exposed in the chamber 1, and a heater 4 is arranged below the lower electrode.

The lower electrode 3 is grounded together with the reaction chicken par 1, and a high frequency electric field g15 is connected between the grounded lower electrode 3 and the upper electrode 2. The substrate 6 to be chemically vapor-deposited is placed on the lower electrode 3, introduced into the chamber 1 from the introduction lower, and discharged in the skin reaction gas to generate plasma sound, and the film forming components in the gas are transferred to the substrate. 6
Chemical vapor phase growth is performed on top. Note that 8 is an exhaust port that communicates with an exhaust I ring (not shown).

Due to the structure of such a device, the plasma formed between the upper electrode and the lower electrode, which serve as the cathode, is like chicken? -1 Has a tendency to spread toward walls. For this reason, the deposition rate of the film growing on the substrate is slow, and particles that have once attached to the chamber wall due to the spreading plasma separate from the chamber wall and fall onto the film that is growing on the substrate. There is
Such particles cause the formation of pinholes in the growing film, resulting in growth and deterioration of the film quality of the growing film.

The present invention was devised in view of the drawbacks of the conventional apparatus as described above, and its purpose is to concentrate plasma near the substrate on which the film is grown, thereby blocking the film formation rate and improving the film quality. The purpose of the present invention is to provide a chemical vapor deposition apparatus in a chemical vapor deposition system.

Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 2 shows the present apparatus, and 10 is a reaction chamber. In this reaction chamber 10, first and second plasma generation electrodes 11 and 12 are installed facing each other and separated from each other.
These electrodes are, for example, flat plate electrodes, and the chamber 1
They are located above and below within 0. The upper electrode 11 is suspended by a shaft 13, which is a suspended body electrically insulated from the chamber 10 and is also a conductor, and is exposed in the chamber 1o. The lower electrode 12tj is supported within the chamber 10 by a support (not shown) and is connected together with the chamber to a reference potential, such as ground potential.
A high frequency power supply 1 for supplying a high frequency voltage capable of generating plasma between KFi and the shaft 13, and between both electrodes 11 and 12.
4 is connected.

A lower Kl-Jl-upper (heating means) 15 of the lower electrode 12 is provided, and a third electrode 17 for mounting a substrate is provided sandwiching the upper Ktj insulator 16 therebetween. A bias power supply 18 is connected between the third electrode 17 and the reference potential for supplying a voltage that is sequentially or averagely negative with respect to the reference potential. 1
Reference numeral 9 represents a reaction gas inlet port that communicates with a reaction gas supply device (not shown), and 20 represents an exhaust port that communicates with an exhaust pump (not shown).

Next, the operation of the apparatus of the present invention constructed as described above will be explained.

The substrate 21 is placed on one of the third electrodes for substrate placement in the reaction chicken parser 10, and after making a hole, a reaction gas is introduced into the reaction chamber 10 from the reaction gas inlet 19, and the upper electrode 11 and the lower electrode 12 to form a reactive gas atmosphere.

A high frequency voltage capable of generating plasma is applied between the upper electrode 11 and the lower electrode 12 which sandwich this reaction gas atmosphere from the high frequency electric voltage 114, and at the same time, a bias voltage 18 is applied to the 11130 electrode 17 at a reference potential. A voltage that is sequentially or averagely negative, that is, a DC voltage or a negatively shifted AC voltage is supplied.

The electric field generated by these voltages causes a discharge between the two electrodes, causing plasma to be generated in the atmosphere. This plasma is caused by the third electrode 17 being negatively biased by /4 with respect to the lower electrode 12, and from the third electrode 17 to the lower electrode 1.
2, the plasma generated between the electrodes 11 and 12 is concentrated near the substrate 21 placed on the third electrode, and attracts the film-forming components in the plasma. K11I is formed on the substrate 21.

The film forming speed is faster than that of the conventional apparatus shown in FIG. 1 because the plasma is concentrated near the substrate by the bias voltage as described above.

In addition, due to the concentration of plasma near the substrate 21, some of the particles grown on the substrate 21 adhere to the chamber wall and then separate from there, causing crystal growth on the substrate 21, unlike in the conventional apparatus. The amount of particles added to the surface is extremely small, and pinholes and the like are almost completely eliminated.

Therefore, the quality of the grown film is further improved.

According to the present invention, the following effects can be obtained for i+ as described above.

(2) Kf2 can be concentrated near the substrate.

(2) Therefore, the film formation rate can be improved.

(2) Also, the film quality is improved.

[Brief explanation of drawings]

Figure 1 is a diagram showing a conventional plasma chemical vapor deposition apparatus;
FIG. 2 is a diagram showing a chemical vapor deposition apparatus in a glazma according to the present invention. In the figure, 10 is a reaction chamber, 1iFi 1 electrode, 1
2 is a second electrode, 14 Ifi high frequency power source, and 18 is a bias power source. Figure 1 Figure 2

Claims (1)

[Claims] 1) All and a second electrode are installed facing each other at a distance in a reaction chamber, are connected to a reference potential among these electrodes, and are heated by a heating hand RK. A third electrode for the M plate device is provided which is electrically connected to the electrode, and a high frequency voltage capable of generating plasma is applied between the first electrode and the second electrode, and the above! It is characterized by being configured to apply a negative voltage with respect to the reference potential to the electrode 1113! Chemical vapor phase growth equipment in wheat bran. 2) The plasma chemical vapor deposition apparatus according to claim 1, wherein the voltage negative with respect to the reference potential is a direct current. 3) The plasma chemical vapor deposition apparatus according to claim 1, wherein a negative voltage with respect to the reference potential is shifted to a positive current.