JPH0896987A - Plasma treatment device - Google Patents

Abstract

PURPOSE: To provide an aluminum(Al) electrode and aluminum(Al) electrode plate structure in which the corrosion of the contact surface between the Al electrode and the Al electrode plate by chlorine gas can be prevented. CONSTITUTION: An electrode part having a gas basin part is formed of an Al electrode 1A and an Al electrode plate 2. Although a protecting film is mounted on the gas contact part of the electrode part, the contact surface between the Al electrode 1A and the Al electrode plate 2 is formed of Al base material for current carrying. To prevent the penetration of chlorine gas to the contact surface, gas blowout holes 4a, 4b for covering the contact surface with an inert gas flow are provided on a cover 4A having the electrode mounted thereon. Thus, the lives of the Al electrode 1A and the Al electrode plate 2 can be extended, and the generation of foreign matter by corrosion can be prevented, so that a plasma treatment device (semiconductor manufacturing device) with high reliability and low running cost can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma for a dry etching apparatus or the like having a structure for preventing corrosion of aluminum (Al) by chlorine-based gas generated on the contact surface between an aluminum (Al) electrode and an aluminum (Al) electrode plate. The present invention relates to a processing device.

[0002]

2. Description of the Related Art A conventional plasma processing apparatus will be described with reference to FIG. FIG. 5A is a diagram showing a sectional structure of an electrode and an electrode plate used in a conventional plasma processing apparatus, and FIG. 5B is an enlarged view of a portion A of FIG.

In FIG. 5, 1 is an electrode made of aluminum (Al) such as a cylindrical container, 2 is an electrode plate made of disc-shaped aluminum (Al), 3 is a wafer to be processed, and 4 is vacuum-sealed. For this purpose, 5 is a processing gas inlet for introducing a chlorine (Cl) -based gas, and 6 is a lower electrode. Here, aluminum electrode 1
The contact surface between the aluminum electrode plate 2 and the aluminum electrode plate 2 is an aluminum base for energizing, and the other surface is provided with a protective film 7 for preventing corrosion.

Next, the operation of the conventional plasma processing apparatus will be described. First, the wafer 3 is placed on the lower electrode 6,
Then, a processing gas such as a chlorine-based gas is introduced from the processing gas inlet 5 and a voltage is applied between the aluminum electrode plate 2 and the lower electrode 6 to generate chlorine-based plasma. The chlorine-based plasma is applied to the wafer 3 to perform a desired process such as etching on the wafer 3.

[0005]

In the conventional plasma processing apparatus as described above, the contact surface between the aluminum electrode 1 and the aluminum electrode plate 2 is provided with the protective film 7 in order to generate plasma by energizing. Not required to be an aluminum substrate. Therefore, as shown in FIG. 5B, the chlorine-based gas in the processing gas invades the contact surface to cause corrosion in the aluminum base portion, and the aluminum electrode 1 and the aluminum electrode plate 2
There was a problem that it shortened the life of the.

There is also a problem that foreign matter is generated from the corroded portion.

The present invention has been made to solve the above-mentioned problems, and it is possible to prevent corrosion of the contact surfaces of the electrodes and the electrode plates and prevent the reduction of the service lives of the electrodes and the electrode plates. An object of the present invention is to obtain a plasma processing apparatus capable of reducing the generation of foreign matter, running cost, and further improving reliability.

[0008]

According to a first aspect of the present invention, there is provided a plasma processing apparatus in which chlorine-based gas is supplied from outside a cover which covers a chamber surrounded by a disc-shaped aluminum electrode plate and a recess-shaped aluminum electrode. Introduced, a voltage is applied between the aluminum electrode and the lower electrode on which the wafer is placed to generate chlorine-based plasma, and in the plasma processing apparatus for applying the chlorine-based plasma to the wafer, the aluminum electrode and the It is provided with an outlet for blowing an inert gas onto the contact surface with the aluminum electrode plate.

In the plasma processing apparatus according to the second aspect of the present invention, the blowout port blows an inert gas from the outside onto the contact surface between the aluminum electrode and the aluminum electrode plate along the inner and outer walls of the chamber. Further, it is provided on the cover and the aluminum electrode.

In the plasma processing apparatus according to the third aspect of the present invention, the blowout port is provided on the aluminum electrode side of the contact surface, and the aluminum electrode plate has a ring shape at a position facing the blowout port. A groove is provided, and an inert gas is blown from the inside to the contact surface due to the pressure difference between the pressure inside the groove and the pressure outside the groove.

In the plasma processing apparatus according to a fourth aspect of the present invention, the blow-out port is provided in the outer peripheral portion and the inner peripheral portion of the contact surface on the side of the aluminum electrode, and further connected to the blow-out port, A groove having a gap between an electrode and the aluminum electrode plate is provided on the contact surface side of the aluminum electrode,
Inert gas that accumulates in the groove is blown out from this gap.

In the plasma processing apparatus according to the fifth aspect of the present invention, the electrode plate further includes a ring-shaped protruding portion having a diameter smaller than the inner diameter of the electrode inside.

[0013]

In the plasma processing apparatus according to the first aspect of the present invention, the chlorine-based gas is introduced from the outside of the cover that covers the chamber surrounded by the disk-shaped aluminum electrode plate and the recessed aluminum electrode, In a plasma processing apparatus for applying a voltage between an electrode and a lower electrode on which a wafer is placed to generate chlorine-based plasma, and applying the chlorine-based plasma to the wafer, the aluminum electrode and the aluminum electrode plate Since it has an outlet for blowing inert gas to the contact surface,
The invasion of chlorine-based gas into the aluminum base portion of the contact surface can be prevented by blowing an inert gas, and the corrosion of the contact surface can be prevented.

In the plasma processing apparatus according to the second aspect of the present invention, the blowout port blows an inert gas from the outside onto the contact surface between the aluminum electrode and the aluminum electrode plate along the inner and outer walls of the chamber. As described above, since the cover and the aluminum electrode are provided, it is possible to prevent chlorine-based gas from entering the aluminum base portion of the contact surface by blowing out an inert gas and prevent corrosion of the contact surface. .

In the plasma processing apparatus according to the third aspect of the present invention, the blowout port is provided on the aluminum electrode side of the contact surface, and the aluminum electrode plate is ring-shaped at a position facing the blowout port. Since the inert gas is blown from the inside to the contact surface due to the pressure difference between the pressure inside the groove and the pressure outside the groove, the invasion of chlorine-based gas into the aluminum base portion of the contact surface is inert. This can be prevented by blowing out gas, and corrosion of the contact surface can be prevented.

In the plasma processing apparatus according to a fourth aspect of the present invention, the blow-out port is provided in an outer peripheral portion and an inner peripheral portion of the contact surface on the aluminum electrode side, and is further connected to the blow-out port, A groove having a gap between the aluminum electrode and the aluminum electrode plate is provided on the contact surface side of the aluminum electrode, and an inert gas accumulating in the groove is blown out from this gap, so that chlorine on the aluminum base portion of the contact surface is discharged. The invasion of the system gas can be prevented by blowing out an inert gas, and the corrosion of the contact surface can be prevented.

In the plasma processing apparatus according to the fifth aspect of the present invention, since the electrode plate further includes a ring-shaped protruding portion having a diameter smaller than the inner diameter of the electrode on the inside, the flow of the processing gas by blowing out the inert gas. Can be suppressed.

[0018]

EXAMPLES Example 1. An embodiment of the present invention will be described with reference to FIG. FIG. 1 (a) is a view showing a sectional structure of an electrode and an electrode plate according to Embodiment 1 of the present invention, and FIG. 1 (b).
[Fig. 4] is a view showing a gas outlet viewed from the right side of the line BB in Fig. (A) (the electrode plate 2 is removed and the right side in Fig. (A)). The aluminum electrode plate 2, the wafer 3, the processing gas introduction port 5, and the lower electrode 6 are the same as in the conventional device. In each figure, the same reference numerals indicate the same or corresponding parts.

In FIG. 1, 1A is an aluminum (Al) electrode provided with a plurality of gas outlets 1a along the inner peripheral portion. 4A is a cover for vacuum sealing, which is a gas inlet 8 and 9 for introducing an inert gas such as nitrogen (N ₂ ) or helium (He), and a continuous gas outlet 4
A plurality of a and 4b are provided at positions along the outer circumference and the inner circumference of the aluminum electrode 1A. The positions of the outlet 4b inside the cover 4A and the outlet 1a of the aluminum electrode 1A are the same. A gas cylinder having a control valve is connected to the gas inlets 8 and 9.

In the plasma processing apparatus having the structure of the aluminum electrode 1A and the aluminum electrode plate 2 configured as described above, the gas introduced into the gas introduction port 8 of the cover 4A passes through the blow-out port 4a and remains as it is. It is blown to the outer side wall of the aluminum electrode 1A. Then, a gas flow is formed on the outer peripheral portion of the contact surface between the aluminum electrode 1A and the aluminum electrode plate 2,
Prevents chlorine-based gas from entering the contact surface.

The gas introduced into the gas inlet 9 is
From the outlet 4b inside the cover 4A through the outlet 1a provided inside the aluminum electrode 1A, the aluminum electrode 1A
Flows from the inner side wall to the contact surface, and prevents chlorine-based gas from entering the inner peripheral portion of the contact surface, like the outer peripheral portion.

In the first embodiment, in order to prevent chlorine-based gas from entering the contact surface between the aluminum electrode plate 2 and the aluminum electrode 1A, an inert gas is provided along the side walls of the electrode 1A and the electrode plate 2. Blow-out ports 1a, 4a, 4b for blowing air are provided. That is, since the chlorine-based gas that enters the aluminum base portion, which is the current-carrying surface of the aluminum electrode 1A and the aluminum electrode plate 2, can be prevented by blowing an inert gas, the aluminum electrode 1A and the aluminum electrode It is possible to obtain a highly reliable device in which corrosion of the plate 2 is suppressed, the life of the plate 2 is extended, and the generation of foreign matter due to corrosion is suppressed.

Example 2. A second embodiment of the present invention will be described with reference to FIG. FIG. 2A is a diagram showing a cross-sectional structure of an electrode and an electrode plate according to Example 2 of the present invention,
FIG. 2B is an enlarged view of the C portion of FIG.

In FIG. 2, an outlet 1b for the inert gas is provided.
Aluminum electrode 1B provided on the contact surface and this outlet 1b
And an aluminum electrode plate 2A provided with a ring-shaped groove 2a. End face 1c of electrode 1B
By making the surface rough, the end face 1c ensures the outflow of gas. The rough surface may be formed on the electrode plate 2A side. The outlet 1b may be one or plural. With this configuration, the inert gas comes into contact due to the pressure difference (P1> P2) between the pressure P1 of the inert gas accumulated in the groove 2a of the aluminum electrode plate 2A and the vacuum (P2) outside the contact surface. It flows out into a vacuum from a minute gap in the surface. This flow prevents chlorine-based gas from entering the contact surface.

In the second embodiment, in order to prevent chlorine-based gas from entering the contact surface between the aluminum electrode plate 2A and the aluminum electrode 1B, the inert gas outlet 1b is brought into contact with the electrode plate 2A and the electrode 1B. It is provided in the portion, and the inert gas is blown out from the contact portion due to the pressure difference between the contact portion and the outside. That is, since the invasion of the chlorine-based gas that enters the aluminum base portion, which is the current-carrying surface of the aluminum electrode 1B and the aluminum electrode plate 2A, can be prevented by blowing the inert gas, the aluminum electrode 1B and the aluminum electrode 1B are prevented. Board 2A
It is possible to obtain a highly reliable device that suppresses the corrosion of the steel, can extend the life, and further suppress the generation of foreign matter due to the corrosion.

Example 3. A third embodiment of the present invention will be described with reference to FIG. FIG. 3A is a diagram showing a cross-sectional structure of an electrode and an electrode plate according to Example 3 of the present invention,
FIG. 2B is an enlarged view of the portion D in FIG.

In FIG. 3, an aluminum (Al) electrode 1C is used.
In addition, the groove 1 is formed on the outer peripheral side and the inner peripheral side of the contact surface with the aluminum electrode plate 2.
d and 1e are provided, and the outlets 1f and 1g of the inert gas are connected to the grooves 1d and 1e. Also, these grooves 1
The outer walls of d and 1e are made slightly lower than the central portion of the contact surface with the aluminum electrode plate 2. This aluminum electrode 1
When C is used, the inert gas accumulated in the grooves 1d and 1e is
It can be uniformly blown out from the entire inner and outer circumferences of the contact surface.

In the third embodiment, in order to prevent chlorine-based gas from entering the contact surface between the aluminum electrode plate 2 and the aluminum electrode 1C, N ₂ gas or the like is applied to the outer peripheral portion and the inner peripheral portion of the contact surface. Ring-shaped groove 1 connected to the outlets 1f, 1g of inert gas
d, 1e are provided, and the clearance between the aluminum electrode 1C and the aluminum electrode plate 2 is made minute, and the grooves 1d, 1
The inert gas accumulating in the portion e can be blown out uniformly. That is, since the chlorine-based gas that enters the aluminum base portion, which is the current-carrying surface of the aluminum electrode 1C and the aluminum electrode plate 2, can be prevented by blowing the inert gas, the aluminum electrode 1C and the aluminum electrode It is possible to obtain a highly reliable device in which corrosion of the plate 2 is suppressed, the life of the plate 2 is extended, and the generation of foreign matter due to corrosion is suppressed.

Example 4. A fourth embodiment of the present invention will be described with reference to FIG. FIG. 4A is a diagram showing a cross-sectional structure of an electrode and an electrode plate according to Example 4 of the present invention,
FIG. 2B is an enlarged view of the E portion of FIG.

In FIG. 4, the diameter is smaller than the inner diameter of the aluminum electrode 1C in order to suppress the influence of the inert gas blown from the groove 1e at the inner peripheral portion of the contact surface of the aluminum (Al) electrode 1C on the flow of the processing gas. Ring-shaped protrusion 1
The aluminum (Al) electrode plate 2B provided with b is used. By this protruding portion 2b, the flow direction of the inert gas blown inside the aluminum electrode 1C is changed upward, and it becomes impossible to prevent the processing gas from flowing out from the aluminum electrode plate 2B.

In the fourth embodiment, in order to prevent chlorine-based gas from invading the contact surface between the aluminum electrode plate 2B and the aluminum electrode 1C, a processing gas by blowing out an inert gas such as N ₂ gas from the contact surface. In order to suppress the influence on the flow, a ceramic ring-shaped protruding portion 2b is provided inside the electrode. That is, it is possible to prevent chlorine-based gas from entering the aluminum base portion, which is the current-carrying surface of the aluminum electrode 1C and the aluminum electrode plate 2B,
Since it is configured so that it can be prevented by spraying an inert gas, corrosion of the aluminum electrode 1C and the aluminum electrode plate 2B can be suppressed, the service life can be extended, and a highly reliable device that suppresses the generation of foreign matter due to corrosion can be obtained. be able to.

[0032]

As described above, in the plasma processing apparatus according to the first aspect of the present invention, the chlorine-based gas is supplied from the outside of the cover that covers the chamber surrounded by the disk-shaped aluminum electrode plate and the recessed aluminum electrode. Is introduced, a voltage is applied between the aluminum electrode and the lower electrode on which the wafer is placed to generate chlorine-based plasma, and the chlorine-based plasma is applied to the wafer in the plasma processing apparatus. Since a blowout port for blowing an inert gas to the contact surface with the aluminum electrode plate is provided, it is possible to prevent the invasion of chlorine-based gas into the aluminum base portion of the contact surface by blowing an inert gas, the contact This has the effect of preventing surface corrosion.

As described above, in the plasma processing apparatus according to the second aspect of the present invention, the blowout port does not contact the contact surface between the aluminum electrode and the aluminum electrode plate along the inner and outer walls of the chamber from the outside. Since the cover and the aluminum electrode are provided so as to blow the active gas, it is possible to prevent the chlorine-based gas from entering the aluminum base portion of the contact surface by blowing out the inert gas, and to prevent the corrosion of the contact surface. The effect is that it can be prevented.

As described above, in the plasma processing apparatus according to the third aspect of the present invention, the blowout port is provided on the aluminum electrode side of the contact surface, and the aluminum electrode plate faces the blowout port. A ring-shaped groove is provided at a position, and since an inert gas is blown from the inside to the contact surface due to the pressure difference between the pressure inside the groove and the pressure outside the groove, the chlorine-based gas to the aluminum base portion of the contact surface Invasion can be prevented by blowing out an inert gas, and corrosion of the contact surface can be prevented.

As described above, in the plasma processing apparatus according to the fourth aspect of the present invention, the blowout ports are provided at the outer peripheral portion and the inner peripheral portion of the contact surface on the aluminum electrode side, and further, the blowout ports and A groove having a gap between the aluminum electrode and the aluminum electrode plate, which is tied together, is provided on the contact surface side of the aluminum electrode, and an inert gas accumulating in the groove is blown from this gap, so that the aluminum base material of the contact surface is formed. It is possible to prevent the invasion of chlorine-based gas into the part by blowing out an inert gas, and it is possible to prevent corrosion of the contact surface.

As described above, in the plasma processing apparatus according to the fifth aspect of the present invention, since the electrode plate further has a ring-shaped protruding portion having a diameter smaller than the inner diameter of the electrode on the inner side, the inert gas is blown out. This has an effect of suppressing the influence on the flow of the processing gas.

[Brief description of drawings]

FIG. 1 is a view showing a cross section of an electrode and an electrode plate according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a cross section of an electrode and an electrode plate according to a second embodiment of the present invention.

FIG. 3 is a diagram showing a cross section of an electrode and an electrode plate according to a third embodiment of the present invention.

FIG. 4 is a diagram showing a cross section of an electrode and an electrode plate according to Example 4 of the present invention.

FIG. 5 is a view showing a cross section of an electrode and an electrode plate of a conventional plasma processing apparatus.

[Explanation of symbols]

1A, 1B, 1C Aluminum electrodes, 2 2A, 2B Aluminum electrode plates, 3 wafers, 4A, 4B covers, 5 processing gas inlets, 6 lower electrodes, 7 protective films, 8 and 9 gas inlets, 10 gas inlets .

Claims (5)

[Claims] 1. A chlorine-based gas is introduced from the outside of a cover that covers a chamber surrounded by a disc-shaped aluminum electrode plate and a concave-shaped aluminum electrode, and the chlorine gas is introduced between the aluminum electrode and a lower electrode on which a wafer is placed. In a plasma processing apparatus for generating a chlorine-based plasma by applying a voltage between them and applying the chlorine-based plasma to the wafer, an outlet for blowing an inert gas onto the contact surface between the aluminum electrode and the aluminum electrode plate. A plasma processing apparatus comprising: 2. The outlet is provided in the cover and the aluminum electrode so as to blow an inert gas from the outside to the contact surface between the aluminum electrode and the aluminum electrode plate along the inner and outer walls of the chamber. The plasma processing apparatus according to claim 1, wherein the plasma processing apparatus is a plasma processing apparatus. 3. The blowout port is provided on the aluminum electrode side of the contact surface, and the aluminum electrode plate has a ring-shaped groove at a position facing the blowout port. The inert gas is blown from the inside to the contact surface due to the pressure difference from the pressure outside the groove.
The plasma processing apparatus described. 4. The blowout port is provided on an outer peripheral portion and an inner peripheral portion of the contact surface on the aluminum electrode side, and is further connected to the blowout port to form a gap between the aluminum electrode and the aluminum electrode plate. The plasma processing apparatus according to claim 1, wherein a groove having a groove is provided on the contact surface side of the aluminum electrode, and an inert gas accumulating in the groove is blown out from the gap. 5. The plasma processing apparatus according to claim 4, wherein the electrode plate is provided internally with a ring-shaped protrusion having a diameter smaller than the electrode inner diameter.