JP3290036B2 - Dry etching apparatus and dry etching method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry etching apparatus and, more particularly, to a dry etching apparatus for preventing a discharge generated near an electrode in a processing chamber from adversely affecting an etching process.

[0002]

2. Description of the Related Art A conventional dry etching apparatus will be described. FIG. 5 is a configuration diagram showing a specific example of a conventional dry etching apparatus. In FIG. 5, 1 is a processing chamber configured to maintain airtightness, 2 is an exhaust path, 10 is a gas hole, 3 is an upper electrode provided with a gas hole 10 so as to penetrate the back and front surfaces, and 4 is A lower electrode 7 is a gas introduction path, 5 is an electrode body which is a supporting member in which a gas introduction path 7 is provided and is connected and supported by the upper electrode 3, and 6 connects the upper electrode 3 and the electrode body 5. A fastener is a screw whose material is a conductor material (for example, SUS, Al, etc.), 8 is a high frequency power supply,
Reference numeral 9 denotes a semiconductor wafer to be processed.

First, the configuration of the above dry etching apparatus will be described. An electrode body 5 is provided at an upper portion in the reaction chamber 1, and an upper electrode 3 is fixed to a lower surface of the electrode body 5 by a screw 6. One end of the gas introduction path 7 has a gas hole 1
0 and the other end goes out of the processing chamber 1. Processing room 1
One end of an exhaust path 2 is connected to the inner bottom surface, and a vacuum pump (not shown) provided outside the processing chamber 1 is connected to the other end of the exhaust path 2. A lower electrode 4 is provided at a lower portion in the processing chamber 1, and a semiconductor wafer 9 is mounted on an upper surface of the lower electrode 4. The electrode body 5 is grounded.
One end of the high frequency power supply 8 is connected to the lower electrode 4 and the other end is grounded. The upper electrode 3 and the lower electrode 4 constitute a pair of parallel plate electrodes.

Next, the operation will be described. After the inside of the processing chamber 1 is evacuated by the vacuum pump through the exhaust path 2, the semiconductor wafer 8 is mounted on the lower electrode 4, and the etching gas is supplied from the outside of the processing chamber 1 through the gas introduction path 7. At the same time, the high-frequency power supply 8 is operated, and a high-frequency voltage is applied between the upper electrode 3 and the lower electrode 4, thereby forming a plasma in the processing chamber 1. An etching process is performed on the semiconductor wafer 9.

During the etching process, the inside of the processing chamber 1 is heated by the plasma. Particularly, the temperature of the upper electrode 3 is raised to about 150 ° C. to about 200 ° C. As a result, thermal distortion occurs in the upper electrode 3. FIG. 6 is an enlarged view of the vicinity of the contact surface between the electrode body 5 and the upper electrode 3 when thermal distortion occurs in the upper electrode 3. In FIG. 6, reference numeral 11 denotes a gap, and other reference numerals indicate those in FIG.
Respectively. As shown in FIG. 6, a gap 11 is generated between the contact surface between the electrode body 5 and the upper electrode 3 due to the thermal strain of the upper electrode 3.

As an example of a path of a current flowing through the upper electrode 3, an example of a path through which a current flows in one direction will be described. FIG. 7 is a diagram showing a current path near the contact surface between the upper electrode 3 and the electrode body 5 when no thermal strain is generated in the upper electrode 3. Arrows in FIG. 7 indicate paths through which current flows. As shown in FIG. 7, when no thermal strain is generated in the upper electrode 3, particularly at a high frequency, it is considered that a current flows through the skin of the upper electrode 3 and a current flows through two paths, the inside and the outside. .

[0007]

However, the gap 1
If a 1 occurs, a problem occurs in the inner current path. FIG. 8 is a diagram showing a current path near the contact surface between the upper electrode 3 and the electrode body 5 when thermal distortion occurs in the upper electrode 3.
The arrows in FIG. 8 indicate the paths through which the current flows, and
It corresponds to each symbol in the figure. As shown in FIG. 8, the outer current path is the same as that shown in FIG. 7, so that there is no problem. However, the inner current path may cause discharge due to the current flowing in the space of the gap 11. I think.

FIG. 9 is a diagram showing a current path near the contact surface between the upper electrode 3 and the electrode body 5 when thermal distortion occurs in the upper electrode 3 similarly to FIG. The arrows in FIG. 9 indicate the paths through which the current flows, and each symbol corresponds to each symbol in FIG. In FIG. 9, the outer current path is the same as that shown in FIG. 7, so there is no problem. However, the inner current path has a current path via the screw 6. Since the discharge is likely to occur at the protrusion, the protrusion between the screw portion of the screw 6 and the surface of the upper electrode 3, or the protrusion of the screw portion of the screw 6 and the surface of the electrode body 5 may be displaced. It is conceivable that a discharge occurs between the two.

When the above-described discharge occurs, the state of the plasma deteriorates, and the members at the discharge point such as the upper electrode 3, the electrode body 5, and the screw 6 at the discharge point deteriorate, thereby causing foreign matters. In addition, there is a problem that the etching process is adversely affected.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and thermal distortion occurs in an upper electrode due to plasma heating during an etching process, and a gap is formed in a contact surface between the upper electrode and the electrode body. It is an object of the present invention to provide a dry etching apparatus in which no discharge occurs in the gap even when the generation occurs.

[0011]

Means for Solving the Problems According to the first aspect of the present invention, there is provided a processing chamber, an electrode disposed in the processing chamber, a support member for supporting the electrode, the electrode and the support. And a conductive material having mechanical elasticity interposed between the first and second members.

According to a second aspect of the present invention, there is provided a processing chamber, an electrode disposed in the processing chamber, a support member for supporting the electrode, and a fastener for connecting the electrode and the support member. And the fastener has a surface shape without projections at least in a portion located near a contact surface between the electrode and the support member. Claim of the invention
The problem solving means according to claim 3 is a processing chamber;
An electrode disposed on, a support member for supporting the electrode,
Mechanical elasticity inserted between the electrode and the support member
Using a dry etching apparatus having a conductive material having
And perform dry etching.

[0013]

In the dry etching apparatus according to the first aspect of the present invention, a processing chamber, an electrode disposed in the processing chamber, a support member for supporting the electrode, and a machine inserted between the electrode and the support member. The conductive material has elasticity so that the conductive material always has contact with both the electrode and the support member because the conductive material has elasticity, and the current flowing through the electrode is supported from the electrode via the conductive material. By flowing to the path that flows to the member,
Generation of electric discharge between the electrode and the component is suppressed.

According to a second aspect of the present invention, there is provided a dry etching apparatus comprising: a processing chamber; an electrode disposed in the processing chamber; a support member for supporting the electrode; and a fastener for connecting the electrode and the support member. Since the fastener has a surface shape without protrusions at least in a portion located in the vicinity of the contact surface between the electrode and the support member, the fastener makes contact when flowing from the electrode to the support member via the fastener. Since there is no protrusion near the surface, one factor of the discharge characteristic that is likely to occur at the protrusion is lost, so the generation of discharge between the fastener and the electrode, or the Intermittent discharge is suppressed.

[0015]

Next, a first embodiment of the present invention will be described. FIG. 1 is a schematic configuration diagram of a dry etching apparatus according to a first embodiment of the present invention. In FIG. 1, reference numeral 12 denotes a conductive grounding member having a ring shape in plan view having mechanical elasticity, reference numeral 13 denotes a groove having a ring shape in plan view, and other reference numerals in FIG. It corresponds to.

First, the configuration of the dry etching apparatus will be described. The difference between the configuration of the conventional dry etching apparatus and the configuration of the dry etching apparatus of the first embodiment is that a groove 13 is provided on the surface of the upper electrode 3 in contact with the electrode body 5 as shown in FIG. The grounding material 12 is fitted into the groove, and the upper electrode 3 is fixed to the lower surface of the electrode body 5 by screws 6 so that the grounding material 12 and the electrode body 5 come into contact with each other. The grounding member 12 is formed by coating a surface of a tube rubber having a ring shape elasticity in plan view with a metal (for example, SU
S, Cu, etc.). Other configurations are the same as those of the dry etching apparatus described in the conventional example.

Next, the operation will be described. The main operation of the dry etching apparatus according to the first embodiment is the same as the operation of the dry etching apparatus described in the conventional example. The difference between the operation of the conventional dry etching apparatus and the operation of the dry etching apparatus according to the first embodiment is that the operation described below is different because the ground material 12 is provided between the upper electrode 3 and the electrode body 5.

During the etching, the upper electrode 3 is heated and heated by the plasma, as in the prior art, causing thermal distortion, and a gap is formed between the upper electrode 3 and the electrode body 5. FIG. 2 shows the electrode body 5 and the upper electrode 3 when thermal strain occurs in the upper electrode 3.
FIG. 4 is an enlarged view near the contact surface of FIG. Reference numeral 11 in FIG. 2 denotes a gap, and other reference numerals correspond to the reference numerals in FIG.
As shown in FIG. 2, since the grounding material 12 has mechanical elasticity, the upper electrode 3 and the electrode body 5 are in contact via the grounding material 12 even when the gap 11 occurs. .

FIG. 3 is a diagram showing a current path near the contact surface between the electrode body 5 and the upper electrode 3 when thermal distortion occurs in the upper electrode 3. Arrows in FIG. 3 indicate current paths, and reference numerals correspond to reference numerals in FIG. As shown in FIG. 3, there is no problem about the current flowing through the outer path, as described in the conventional example. Since the inner path flows the shortest distance between the surface of the upper electrode 3 and the surface of the electrode body 5 via the grounding material 12, it is possible to prevent the occurrence of discharge as described in the conventional example.

With the above-described configuration, thermal distortion occurs in the upper electrode 3 due to plasma heating during the etching process, and a gap 1 is formed in the contact surface between the upper electrode 3 and the electrode body 5.
Even when 1 occurs, a dry etching apparatus in which discharge does not occur in the gap 11 is obtained, and as described in the conventional example, the occurrence of discharge deteriorates the plasma state or deteriorates the member at the discharge location. Thereby, the problem that foreign matter is generated and adversely affects the etching process can be solved.

Next, a second embodiment will be described. As shown in FIG. 9 described in the conventional example, when a current flows through the screw 6, the current flows between the protrusion, which is the thread of the screw 6, and the surface of the upper electrode 3, or at the thread of the screw 6. Although a discharge occurs between a certain protrusion and the surface of the electrode body 5, the second embodiment prevents the discharge from occurring in this case.

The main structure of the dry etching apparatus of the second embodiment is the same as that of the dry etching apparatus of the prior art shown in FIG. The difference is in the part of the screw 6, which will be described below. FIG. 4 is an enlarged view of the vicinity of the contact surface between the electrode body 5 and the upper electrode 3 when thermal distortion occurs in the upper electrode 3 in the dry etching apparatus of the second embodiment. Reference numeral 14 in FIG. 4 corresponds to 6 in FIG. 5, and is a fastener for connecting the upper electrode 3 and the electrode body 5, and the material thereof is a screw made of a conductor material (for example, SUS, Al, or the like), or another screw. Reference numerals and parts not shown are the same as those of the conventional dry etching apparatus shown in FIG.
The configurational difference between the second embodiment and the conventional example lies in the shape of the screw 14, and when the screw 14 is tightened, at least a portion located near the contact surface between the electrode body 5 and the upper electrode 3. , The surface shape of the screw 14 is set so that there is no screw thread as a projection. By doing so, even if a gap 11 is formed between the upper electrode 3 and the electrode body 5 as shown in FIG. 4, the shape of the surface of the screw 14 exposed in the gap 11 is a screw which is a projection. You will not have a mountain.

Next, the operation will be described. The main operation of the dry etching apparatus of the second embodiment is the same as that of the dry etching apparatus of FIG. The difference in operation between the second embodiment and the conventional example is that since the shape of the surface of the screw 14 exposed in the gap 11 has no thread, the occurrence of discharge, which is likely to occur at the protrusion, is generated. Since one factor of the characteristic is lost, generation of discharge can be prevented.

With the above structure, thermal distortion occurs in the upper electrode 3 due to the plasma heating during the etching process, and the gap 1 is formed in the contact surface between the upper electrode 3 and the electrode body 5.
Even when 1 occurs, a dry etching apparatus in which discharge does not occur in the gap 11 is obtained, and as described in the conventional example, the occurrence of discharge deteriorates the plasma state or deteriorates the member at the discharge location. Thereby, the problem that foreign matter is generated and adversely affects the etching process can be solved.

[0025]

According to the first aspect of the present invention, since the conductive material has elasticity, it always contacts both the electrode and the support member, and the current flowing through the electrode flows from the electrode to the support member via the conductive material. By flowing in the path, the occurrence of discharge between the electrode and the component is suppressed, so that the occurrence of the discharge deteriorates the plasma state or the member at the discharge location, thereby causing foreign matter to be generated. This has an effect that a phenomenon that adversely affects the etching process can be suppressed.

According to the second aspect of the present invention, when flowing from the electrode to the supporting member through the fastener, the fastener has no protrusion near the contact surface, and thus is easily discharged at the protrusion. Because one factor is lost, the occurrence of discharge between the fastener and the electrode, or the occurrence of discharge between the fastener and the support member is suppressed, and the occurrence of discharge deteriorates the plasma state. In addition, it is possible to suppress a phenomenon that a member at a discharge location is deteriorated, thereby causing a foreign substance to adversely affect an etching process. According to the third aspect of the present invention, the conductive material has elasticity.
Contact both the electrode and the support member to
The flowing current flows from the electrode to the support member via the conductive material
By flowing in the path, the discharge between the electrode and the component is generated
Because the generation of electricity is suppressed, the occurrence of discharge
Deteriorates, or the members at the discharge location deteriorate.
Foreign matter may affect the etching process.
It has the effect that the phenomenon of blurring can be suppressed.
You.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a dry etching apparatus according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of the vicinity of the contact surface between the electrode body and the upper electrode when thermal distortion occurs in the upper electrode in the first embodiment of the dry etching apparatus of the present invention.

FIG. 3 is a diagram showing a current path near a contact surface between the electrode body and the upper electrode when thermal distortion occurs in the upper electrode in the first embodiment of the dry etching apparatus of the present invention.

FIG. 4 is an enlarged view of the vicinity of the contact surface between the electrode body and the upper electrode when thermal distortion occurs in the upper electrode in the second embodiment of the dry etching apparatus of the present invention.

FIG. 5 is a configuration diagram showing a specific example of a conventional dry etching apparatus.

FIG. 6 is an enlarged view of the vicinity of the contact surface between the electrode body and the upper electrode when thermal distortion occurs in the upper electrode in the conventional dry etching apparatus.

FIG. 7 is a diagram showing a current path near a contact surface between an upper electrode and an electrode body when thermal distortion is not generated in the upper electrode in a conventional dry etching apparatus.

FIG. 8 is a diagram showing a current path near a contact surface between an upper electrode and an electrode body when a thermal distortion is generated in the upper electrode in a conventional dry etching apparatus.

FIG. 9 is a diagram showing a current path near a contact surface between an upper electrode and an electrode body when thermal distortion occurs in the upper electrode in a conventional dry etching apparatus.

[Explanation of symbols]

1 processing chamber, 2 exhaust path, 3 upper electrode, 4 lower electrode, 5 electrode body, 6 screw, 7 gas introduction path, 8 high frequency power supply, 9 semiconductor wafer, 10 gas hole, 11 gap, 12 grounding material, 13 groove, 14 screws.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masato Toyota 4-1-1 Mizuhara, Itami-shi, Hyogo Mitsubishi Electric Machinery Co., Ltd. Kita-Itami Works (72) Yasuo Nakatani 4-1-1 Mizuhara, Itami-shi, Hyogo Mitsubishi Electric (56) References JP-A-6-112168 (JP, A) JP-A-6-168912 (JP, A) JP-A-7-335628 (JP, A) JP-A-4- 354876 (JP, A) JP-A-61-267326 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C23F 4/00 H01L 21/3065

Claims (3)

(57) [Claims] A processing chamber; an electrode disposed in the processing chamber; a support member supporting the electrode; and a conductive material having mechanical elasticity interposed between the electrode and the support member. And a dry etching apparatus comprising: 2. A processing chamber, an electrode disposed in the processing chamber, a support member supporting the electrode, and a fastener connecting the electrode and the support member, wherein the fastener includes: A dry etching apparatus having a surface shape without projections at least in a portion located near a contact surface between the electrode and the support member. 3. A processing chamber, an electrode disposed in the processing chamber, a support member for supporting the electrode, and mechanical elasticity interposed between the electrode and the support member.
Using a dry etching apparatus provided with a conductive material having
Dry etching method for performing etching.