JPH0517880Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a plasma reaction processing apparatus used for etching semiconductor wafers, removing organic films formed on wafer surfaces, and the like.

(Prior art) In the manufacturing process of semiconductor integrated circuits, a substrate (sample) such as a silicon wafer is selectively etched, or a wafer surface is coated as a mask material during selective etching. A reaction processing apparatus using plasma has been conventionally used as an apparatus for removing organic films (resists).

There are two types of plasma reaction processing equipment: a batch type that processes many samples at the same time, and a single wafer processing type that processes each sample one by one. Does not act uniformly on each sample. As a result, the plasma reaction becomes non-uniform, and in recent years, single-wafer processing type reaction processing apparatuses have become mainstream for the miniaturization of semiconductor integrated circuits.

The general structure of a single-wafer processing type plasma reaction processing device is that a pair of electrodes is placed in a bell-shaped chamber, and a sample is placed inside the chamber by applying high-frequency power under reduced pressure to these electrodes. It is designed to generate plasma.

However, in the conventional reaction processing apparatus described above, since the sample is directly exposed to plasma and subjected to various treatments, there is a problem that the sample is easily damaged by ions, charged particles, etc. in the plasma.

Therefore, Japanese Patent Publication No. 54-32740 proposed a system in which an internal electrode is disposed within a chamber and the chamber is divided into a plasma generation chamber and a reaction processing chamber by a metal plate having porous holes.

(Problem to be solved by the invention) As mentioned above, if the inside of the chamber is divided into a plasma generation chamber and a reaction processing chamber, charged objects such as ions and charged particles generated in the plasma generation chamber can be removed from metal plates. However, since both the external and internal electrodes have a curved shape that follows the shape of the cylindrical chamber, the intensity of the generated plasma can be reduced. This has the disadvantage that the sample processing becomes non-uniform within the chamber, and as a result, there is variation in the processing of the sample locally, that is, between the periphery and the center.

(Means for Solving the Problems) In order to solve the above problems, the present invention disposes an external electrode outside the processing chamber, and generates plasma inside the processing chamber by using an internal electrode with many small holes. It is divided into a chamber and a reaction processing chamber, and a sample mounting table for processing samples one by one faces the reaction processing chamber, and furthermore, the external electrodes, internal electrodes, and the upper surface of the sample mounting table all maintain a parallel relationship. I did it like that.

(Example) An example of the present invention will be described below based on the attached drawings.

Fig. 1 is a front view of a plasma reaction processing apparatus according to the present invention, and Fig. 2 is a cross-sectional view of the same plasma reaction processing apparatus. The upper part of the main body 2 is closed with a plate-shaped quartz glass 3, and a thin metal external electrode 5 connected to a high frequency oscillator 4 is provided on the upper surface of the quartz glass 3.

Further, the bottom of the main body 2 is closed with a bottom plate 6, and the main body 2, the quartz glass 3, and the bottom plate 6 form a chamber 7.

An internal electrode 8 is provided in the middle of the main body 2 and is opposed to the external electrode 5.
is made of a thin metal plate like the external electrode, and has a large number of small holes 9 formed over the entire surface, and this internal electrode 8 connects the inside of the chamber 7 to the plasma generation chamber S ₁ in the upper part and the reaction processing chamber in the lower part. It is separated into S ₂ .
A window 10 and a reaction gas inlet 1 are provided on the side wall of the main body 2 forming the plasma generation chamber S ₁ for monitoring the inside.
A window 12 is formed on the side wall of the main body 2, which forms the chamber 1 and the reaction processing chamber _S2 , for monitoring the inside, and a gas exhaust is formed on the bottom plate 6 for discharging the gas in the chamber 7 to the outside. An outlet 13 is formed.

Further, a large-diameter hole 14 is formed in the center of the bottom plate 6, and a sample mounting table 15 for mounting the sample W from below is inserted into this hole 14. This sample mounting table 15 is fitted airtightly into the hole 14 and can be slid up and down along the inner circumference of the hole 14.
Furthermore, the flat upper surface of the sample mounting table 15 and the external electrodes 5 and internal electrodes 8 are parallel to each other.

FIG. 3 is a sectional view of another embodiment, in which the main body 20 is made of synthetic quartz, and a thin metal plate connected to the high frequency oscillator 4 is attached to the outer upper surface of the main body 20. The external electrode 5 is connected to the main body 20
The chamber 7 formed by the main body 20 and the bottom plate 6 is divided into a plasma generation chamber S ₁ and a reaction processing chamber S ₂ at an intermediate position within the inner electrode. Further, a sample mounting table 15 is hermetically fitted to the bottom plate 6 so as to be vertically slidable, and the upper surface of the sample mounting table 15, the external electrodes 5, and the internal electrodes 8 are parallel to each other.

Using the plasma reaction processing apparatus configured as described above, the sample W on the sample mounting table is etched.
To perform a process such as removing an organic film or cleaning, first place one sample W on the upper surface of the sample mounting table 15, then pull down the sample mounting table 15, and
The hole 14 formed in the bottom plate 6 allows the sample mounting table 15 to be positioned below the bottom plate 6.
Slide the inside so that the sample W faces into the reaction processing chamber _S2 .

Thereafter, the inside of the chamber 7 is depressurized to a predetermined pressure through the exhaust port 13, and a reactive gas is introduced into the chamber 7 through the inlet 11, and high-frequency power is applied to the external electrode 5. Generate plasma in _S1 .

Then, the radicals (active ingredients that participate in the reaction) generated in the plasma generation chamber _S1 reach the surface of the sample W through the small holes 9 of the internal electrode 8, but
Charged particles such as ions and charged particles that damage the sample are collected by the internal electrode 8.

After processing for a predetermined period of time, the reduced pressure in the chamber is released, the sample mounting table 15 is pulled down, and the sample W is taken out.

(Effects of the invention) As explained above, according to the invention, the inside of the chamber of the plasma reaction processing apparatus is separated into the plasma generation chamber and the reaction processing chamber by the internal electrode formed with a large number of small holes. Most of the harmful components that cause damage are removed before they reach the sample, and only radicals can be allowed to reach the sample, allowing various treatments to be performed quickly and with high precision. Furthermore, since the external electrodes, internal electrodes, and the upper surface of the sample mounting table are made parallel to each other, the intensity of the plasma to the sample can be made uniform, and the sample can be processed with high uniformity.

[Brief explanation of drawings]

FIG. 1 is a front view of a plasma reaction processing apparatus according to an embodiment of the present invention, FIG. 2 is a sectional view of the same plasma reaction processing apparatus, and FIG. 3 is a sectional view of a plasma reaction processing apparatus according to another embodiment. It is. In addition, in the drawing, 1 is a plasma reaction processing device, 2, 2
0 is a main body, 5 is an external electrode, 7 is a chamber, 8 is an internal electrode, 9 is a small hole, 15 is a sample mounting table, S ₁ is a plasma generation chamber, S ₂ is a reaction processing chamber, and W is a sample.

Claims (1)

[Scope of utility model registration request] An external electrode is provided on the outside of the chamber, and an internal electrode with a large number of small holes that faces the external electrode is placed inside the chamber, thereby dividing the inside of the chamber into an upper plasma generation chamber and a lower reaction processing chamber. A sample mounting table for processing samples one by one faces the reaction processing chamber, and the external electrodes,
A plasma reaction processing apparatus characterized in that internal electrodes and the upper surface of a sample mounting table are arranged in a parallel relationship.