JPH0437124A - Plasma processor - Google Patents

Abstract

PURPOSE:To uniformly supply reaction gas on a material to be processed from a porous plate, and to uniformly plasma-process the material by providing the plate on the surface of either one of a pair of opposed parallel flat plate electrodes. CONSTITUTION:In a plasma processor having a pair of parallel flat plate electrodes 2, 4 opposed to a reaction vessel 1, a porous plate 3 is provided on the surface of either one of the electrodes 2, 4. For example, a shower plate 3 made of porous silicon carbide having 40-50% of pore ratio is provided on the electrode 2. A material 5 to be processed is placed on the electrode 4, and the vessel is evacuated in vacuum. Then, reaction gas is uniformly supplied onto a material 7 to be processed through the plate 3 made of the carbide on the electrode 2, and regulated to a predetermined pressure. Thereafter, a high frequency power is applied from a high frequency power source 7 to the electrode 4 to dry etch the material 7 to be processed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to dry etching equipment and plasma CVD equipment for semiconductor manufacturing equipment and the like.

2. Description of the Related Art In recent years, semiconductor devices have become increasingly finer, and the use of plasma processing equipment such as dry etching and CVD is increasing in the manufacturing process.

An example of the above-mentioned conventional plasma processing apparatus will be described below with reference to the drawings.

FIG. 2 shows a sectional view of a reaction chamber of a dry etching apparatus, which is a conventional plasma processing apparatus.

1 is a reaction vessel, 2 is an upper electrode, 4 is a lower electrode to which high-frequency power is applied, 5 is an object to be processed, 6 is an automatic matching device, 7 is a high-frequency power source, 8 is a reaction gas control system, and 9 is a vacuum exhaust system , 10
is a shower plate that supplies reaction gas.

FIG. 3 is a configuration diagram of the shower plate 10, in which a large number of holes with a diameter of 0.6 m are drilled through the shower plate 10 at intervals of 10 s*.

The operation of the dry etching apparatus constructed as described above will be explained below.

First, the object to be treated 5 is placed on the lower electrode 4, and the reaction vessel 1 is
is evacuated, a reaction gas is supplied through the shower plate 10 on the upper electrode 2, and the pressure is adjusted to a desired degree of vacuum. Thereafter, high frequency power is applied to the lower electrode 4 by a high frequency power source 7 to dry-etch the object 7.

Problems to be Solved by the Invention However, in the above configuration, the reaction gas is supplied from the holes of the shower plate with a diameter of 0.6-1 and an interval of 10 cm, so that the gas overflow may occur on the object to be treated. Nonuniformity occurs, and within the surface of the workpiece, the etching rate is high immediately below the gas supply hole, and the etching speed is slow in areas other than directly under the gas supply hole.As a result, within the surface of the workpiece, There was a problem in that the pattern of the gas holes on the upper shower plate was transferred, resulting in poor uniformity.

This phenomenon occurred particularly frequently in radical etching such as silicon-based etching using linear radicals.

In order to solve the above-mentioned problems, conventional methods have been used to improve the gas supply system, such as 1) reducing the interval between gas holes, and 2) using a double shower plate.

However, in 1), since the hole diameter is small, processing is labor-intensive and increases the processing cost, and microscopically, non-uniformity of etching cannot be improved. The inhomogeneity of the gas within has not been improved.

Means for Solving the Problems In order to solve the above problems, the plasma processing apparatus of the present invention includes a porous shower plate for supplying a reactive gas on the surface of the electrode facing the object to be processed.

Effects According to the present invention, with the above-described configuration, the reactant gas is uniformly supplied onto the object to be processed from the porous shower plate, so that the object to be processed can be uniformly plasma-treated.

EXAMPLE Hereinafter, a plasma processing apparatus according to an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a cross-sectional view of a reaction chamber of a dry etching apparatus which is a plasma processing apparatus according to an embodiment of the present invention.

In Figure 1, 3 is a shower plate made of porous alumina, with a porosity of 45-50% and an air permeability of 8.
×10. The rest of the equipment is similar to conventional dry etching equipment.

The operation of the dry etching apparatus constructed as described above will be explained below with reference to FIG.

First, the object to be processed 5 is placed on the lower electrode 4, and the reaction container is evacuated. Next, the reaction gas is uniformly supplied onto the object to be processed 7 through the shower plate 3 made of porous alumina on the upper electrode 2, and the pressure is regulated to a desired level. after that,
High frequency power is applied to the lower electrode 4 by a high frequency power source 7,
The object to be processed 7 is dry etched.

As described above, according to this embodiment, a porous alumina shower plate for supplying a reactive gas is provided on the electrode surface facing the object to be treated, so that the reactive gas seeps out from the electrode surface onto the object to be treated. can be supplied uniformly, and unlike conventional methods, transfer of the gas hole position does not occur on the processed object.
Uniform etching becomes possible.

In the examples, the material of the porous shower plate provided on the surface of the electrode facing the object to be processed was alumina, but it may also be alumina.

Furthermore, in the embodiments, the plasma processing apparatus is a dry etching apparatus, but it may also be a plasma CVD apparatus.

Effects of the Invention As described above, the present invention provides a gas permeable porous gas supply plate on the electrode surface facing the object to be processed, thereby uniformly plasma processing the object to be processed without transferring gas holes. can do.

[Brief explanation of drawings]

FIG. 1 is a plan view and a sectional view of a plasma-treated shower plate in an embodiment of the present invention. 1... Reaction container, 2... Upper electrode, 3
... Shower plate, 4 ... Lower electrode. Name of agent: Patent attorney Shigetaka Awano Idiot Ii
A to self'L to mavPt pole 3-, showerap L-1 4---Ttytt life

Claims (3)

[Claims] (1) A plasma processing apparatus having a pair of parallel plate electrodes facing a reaction vessel, characterized in that a porous plate is provided on the surface of one of the electrodes. (2) The plasma processing apparatus according to claim 1, wherein the porous plate is made of alumina. (3) The plasma processing apparatus according to claim 1, wherein the material of the porous plate is silicon carbide.