JPH02234419A - Plasma electrode - Google Patents

Abstract

PURPOSE:To allow mixture gas to react until it reaches a wafer to cause the reaction product to be dust, preventing a CVD reaction chamber or an etching chamber, etc., from being contaminated by a method wherein when two or more kinds of material gas or etching gas are to be used, these kinds of gas are separately supplied to an electrode and plasma. CONSTITUTION:Material gas or etching gas introduced from a first gas inlet tube 7 with its flow rate adjusted flows out from a plurality of first gas outlet ports 10 to enter plasma. Material gas or etching gas introduced from a second gas inlet tube 8 with its flow rate adjusted flows out from a plurality of second gas outlet ports 11 to enter the plasma. Therefore these two kinds of gas are not mixed in advance but supplied to the plasma separately. This allows reaction product to be dust preventing a CVD reaction chamber or an etching chamber from being contaminated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a plasma electrode of a plasma CVD device or a plasma etching device used for manufacturing semiconductor devices such as LSIs.

(Prior art) Chemical vapor deposition method (hereinafter referred to as CVD method) is a chemical vapor deposition method (hereinafter referred to as CVD method) in which one or more compound gases consisting of elements constituting a thin film are sent to the substrate surface and chemically reacted on the substrate surface to form the desired thin film. This is a method of forming.

CVD method Niha normal pressure CVD method, low pressure CVD method, plasma C
Although there are techniques such as the VD method, the plasma CVD method has been increasingly used in recent years because it allows film formation at low temperatures.

Plasma CVD method is 50℃ under reduced pressure of 0.1 to ITorr.
This is a method of generating a thin film by generating plasma by high frequency excitation of K}-1z to 13.56MHz.

Also, using the resist pattern as a mask, the underlying R
P. Planar plasma etching is one of the etching techniques for etching l.

This etching method is a method in which an etchant is introduced into plasma to generate ions having kinetic energy and chemically active radicals, and etching is performed using these.

The structure of the apparatus used in the plasma CvD method or the planar plasma etching method as described above is almost the same, and FIG. 1 shows a cross-sectional view of a conventionally commonly used apparatus.

In the figure, circular parallel plate electrodes 1 and 2 are installed, a wafer 3 is placed on the lower ground electrode 2, and a high frequency voltage is applied to the upper electrode 1 to cause a glow discharge between the upper and lower electrodes. Ru.

In the case of a plasma CVD apparatus, the raw material gas whose flow rate is adjusted flows into the gas inlet pipe 4 together with the carrier gas, and is exhausted from the exhaust pipe 5.

As shown in FIG. 1, the upper electrode 1 has a mesh or sieve-like opening on the electrode surface so that the raw material gas or etching gas that has flowed in can enter the plasma as uniformly as possible from each opening. It has been devised.

However, in the case where the plasma electrode as described above uses two or more kinds of raw material gases or etching gases, it is necessary to mix these gases in advance and introduce them into the plasma from the gas inlet pipe 4.

For this reason, the mixed gas reacts by the time it reaches U-I-Ha,
There is a disadvantage that the reaction product becomes dust and contaminates the CVD reaction chamber or etching chamber.

In addition, in the case of the plasma CVD method, pressure distribution tends to occur in the electrode, such as high pressure in the center of the electrode, which may result in uneven plasma concentration, thickness, and quality of the formed film, and There are disadvantages such as the reaction products of the raw materials increase in the center, resulting in less raw material supply, and the film formed at the center of the electrode becomes thinner, resulting in uneven film quality distribution. .

(Problems to be Solved) The present inventors have previously proposed Japanese Patent Applications Heisei 1-4458 and Heisei 1-20269 as novel electrodes that eliminate the above drawbacks.
has been applied for.

The present invention relates to improvements to these inventions.

(Means for Solving the Problems) In the present invention, when two or more types of raw material gases or etching gases are used, these gases are supplied separately into the electrode and into the plasma.

FIG. 2 is a sectional view of the upper electrode according to the present invention.

The present invention will be explained in detail with reference to FIG.

The raw material gas or etching gas introduced from the first gas introduction pipe 7 with its flow rate adjusted flows out from the plurality of first gas outlet ports 10 and enters the plasma.

The raw material gas or etching gas introduced from the second gas introduction pipe 8 with its flow rate adjusted flows out from the plurality of 20,000th outlet ports 11 and enters the plasma.

Therefore, these two types of gases are not mixed beforehand, but are separately supplied into the plasma.

On the other hand, reaction products of raw materials, reaction residual gas, etching products, etching residual gas, etc. are sucked through the plurality of exhaust ports 12 and exhausted from the exhaust pipe 9.

Therefore, the exhaust pipe 5 as shown in FIG. 1 is not necessarily required.

Figure 2 shows an example of the structure of a plasma electrode when two types of gas are supplied, but when three types of gas are supplied, it is sufficient to increase the number of gas inlet pipes and gas outlet ports. When supplying , the structure of the electrode can be designed using the same concept.

By structuring the upper electrode as described above, it is not necessary to mix two or more kinds of source gases or etching gases in advance, and they can be supplied into the plasma in separate systems.

<<Effects of the Invention>> According to the present invention, two or more raw material gases or processing gases are transported in separate systems within the plasma electrode and supplied into the plasma without being mixed in advance.
The mixed gas reacts and the reaction product becomes dust before reaching the wafer, which does not contaminate the CVD reaction chamber, etching chamber, etc., and is therefore extremely clean.

Further, according to the present invention, in the case of plasma CVD, the amount of raw material supplied is made uniform over the substrate, and a film with an extremely uniform thickness can be formed overall, and since no pressure distribution occurs on the electrode, the plasma concentration is It has the characteristic that the thickness, quality, etc. of the formed film are uniform.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional plasma CVD apparatus or planar plasma etching apparatus. In the figure, 1 is an upper electrode, 2 is a lower electrode, 3 is a wafer, 4 is a gas inlet pipe, 5 is an exhaust pipe, and 6 is a CVD reaction chamber or an etching chamber. FIG. 2 is an example of a cross-sectional view of the upper electrode according to the present invention. In the figure, 7 is a first gas inlet pipe, 9 is an exhaust pipe, 11 is a second gas outlet, gas inlet pipe 8 is a second gas outlet, 10 is a first gas outlet, and 12 is an exhaust port.

Claims (1)

[Claims] A plasma electrode characterized in that two or more types of gas can be supplied through separate systems.