JPH08293539A - Semiconductor manufacturing method and device - Google Patents

Abstract

PURPOSE: To enable a semiconductor manufacturing device to electrostatically attract a work more securely and to be enhanced in work processability. CONSTITUTION: A semiconductor manufacturing device is composed of a specimen pad 3 provided with a work mounting surface 3a which is coated with an insulating film 2 and where a wafer 1 is placed, an insulating ring member 4 whose inner circumferential face 1a is smaller than a wafer 1 in diameter, a cover member 5 possessed of an inner circumferential face 5a corresponding to the side face 1a of the wafer 1 and larger than the wafer 1 in diameter, a high-frequency power supply 7 which generates plasma in the vicinity 6 of the wafer 1 placed on the work mounting surface 3a, and a DC power supply 8 which generates an electrostatic attraction on the work mounting surface 3a of the specimen pad 3. Furthermore, the work mounting surface 4b of the insulating ring member 4 is set level with the surface 2a of the insulating film 2 by polishing, and the wafer 1 is held by electrostatic attraction in such a way that the back periphery of the wafer 1 is brought into close contact with the work mounting surface 4b of the insulating ring member 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing technique in which an object to be processed is placed on a sample stage for processing, and more particularly to a semiconductor manufacturing method and apparatus for holding the object to be processed by electrostatic attraction. .

[0002]

2. Description of the Related Art The techniques described below are for studying the present invention,
The present invention was studied by the present inventors upon completion, and its outline is as follows.

When a semiconductor wafer (hereinafter simply referred to as a wafer), which is an example of an object to be processed, is held by electrostatic attraction when processing the object to be processed using plasma, aluminum is used as a base material. Often.

Therefore, an oxide insulating material powder such as alumina is sprayed on the object mounting surface on which the wafer is mounted to form a film, which is used as a dielectric.

Further, a ceramic cover is arranged on the outer peripheral portion of the wafer, and the local portion of the ceramic cover is also made to dig into the back surface side of the outer peripheral portion of the wafer.

An electrostatic chuck for holding a wafer by electrostatic attraction is disclosed in, for example, Japanese Patent Laid-Open No. 63-194.
It is described in Japanese Patent No. 345.

[0007]

However, in the above-mentioned technique, the sample mounting surface (electrostatic adsorption surface) of the sample table is mounted.
Since it is necessary to isolate the ceramic cover from the plasma, from the technical aspects such as wafer transfer accuracy, orientation flat alignment accuracy, and processing accuracy, the ceramic cover is placed 3 m from the wafer outer periphery to the back surface of the wafer outer periphery.
It has been installed with a depth of about m.

Further, the outer peripheral portion of the object mounting surface on which the wafer is placed adopts R chamfering from the technical aspect of thermal spraying so as to prevent peeling of the thermal spray coating.

As a result, when the wafer is subjected to etching treatment, the outer peripheral portion of the wafer is insufficiently cooled or the high frequency is not applied, and there is a problem that uniformity is deteriorated due to a large variation of the etching rate within a range of about 10 mm from the outer periphery. .

Further, in the outer peripheral portion of the wafer, since there is a gap between the rear surface of the outer peripheral portion of the wafer and the ceramic cover, plasma wraps around the gap, thereby etching near the rear surface of the outer peripheral portion of the wafer (abnormal discharge). )
The problem occurs.

Therefore, it is an object of the present invention to provide a semiconductor manufacturing method and apparatus for improving the reliability of electrostatic attraction and the processing characteristics of an object to be processed.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0013]

Of the inventions disclosed in the present application, a representative one will be briefly described below.
It is as follows.

That is, in the semiconductor manufacturing method of the present invention, the object to be processed is placed on the object mounting surface of the sample table, plasma is generated in the peripheral part of the object to be processed, and the outer peripheral part of the object to be processed is generated. A method of processing the object to be processed by electrostatically holding the object to be processed by electrostatically holding the object to be processed by electrostatically holding the back surface in close contact with the object mounting surface of the insulating ring member installed on the sample table. Is.

Further, the semiconductor manufacturing apparatus according to the present invention includes a sample table, which holds an object to be processed by suction and has a film made of an insulating material formed on the object mounting surface on which the object is mounted, An insulative ring member having an inner peripheral surface having a diameter smaller than the diameter of the object to be processed and installed on the sample stage,
An insulating cover member having an inner peripheral surface corresponding to the side surface of the object to be processed and having a diameter of the inner peripheral surface larger than the diameter of the object to be processed, and the object mounting surface of the sample table. And a voltage applying means for generating an electrostatic attraction force, and the surface of the insulating ring member on which the object to be processed is mounted and the surface of the film are formed on the same surface.

Further, the semiconductor manufacturing apparatus according to the present invention is
A sample table on which a film made of an insulating material is formed on the object mounting surface for holding the object to be processed by suction and mounting the object to be processed, and an inner peripheral surface having a diameter smaller than the diameter of the object to be processed. And an insulating ring member installed on the sample table, and an inner peripheral surface corresponding to the side surface of the object to be processed, and the diameter of the inner peripheral surface is formed to be larger than the diameter of the object to be processed. An insulative cover member, a plasma generating means for generating plasma in the peripheral portion of the workpiece mounted on the workpiece mounting surface of the sample stage, and an electrostatic attraction force on the workpiece mounting surface of the sample stage. And a surface for mounting the object to be treated of the insulating ring member and the surface of the film are formed on the same surface.

In the semiconductor manufacturing apparatus according to the present invention, the film formed on the sample mounting surface of the sample table is a film formed by spraying a powdery insulating material.

Further, in the semiconductor manufacturing apparatus according to the present invention, the object mounting surface of the insulating ring member installed on the sample table and the surface of the film are formed on the same surface by polishing.

[0019]

According to the above-mentioned means, the insulating ring member having an inner peripheral surface having a diameter smaller than that of the object to be processed and installed on the sample stage, and the inner peripheral surface corresponding to the side surface of the object to be processed. And an insulating cover member in which the diameter of the inner peripheral surface is formed larger than the diameter of the object to be processed, and the object mounting surface of the insulating ring member and the surface of the film are formed on the same surface. By doing so, it is possible to reduce the amount of the insulating ring member that digs into the back surface of the outer peripheral portion of the workpiece.

As a result, the area of the sample mounting surface (electrostatic adsorption surface) of the sample table can be increased.

Further, since the area of the workpiece mounting surface of the sample table can be increased, the cooling area due to the workpiece contacting the workpiece mounting surface can be increased.

Further, since the area of the workpiece mounting surface of the sample table can be increased, the application area of the high frequency power source can be increased.

As a result, it is possible to improve the processing uniformity of the object to be processed.

The film formed on the surface of the sample table on which the workpiece is mounted is a film formed by spraying a powdery insulating material,
In addition, since the object mounting surface of the insulating ring member and the surface of the film are formed on the same surface by polishing,
When the object to be processed is held by electrostatic attraction, the outer peripheral back surface of the object to be processed can be held in close contact with the object mounting surface of the insulating ring member.

As a result, it is possible to prevent the plasma from flowing around the back surface of the outer peripheral portion of the object to be processed (abnormal discharge).

[0026]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a partial sectional view showing an example of the structure of an etching apparatus which is an embodiment of the semiconductor manufacturing apparatus according to the present invention.

First, the semiconductor manufacturing apparatus of the present embodiment is an etching apparatus for performing an etching process on a wafer 1, which is an object to be processed, by using plasma. The structure thereof will be described. The sample stage 3 which is a stage on which the coating 2 made of an insulating material is formed on the object mounting surface 3a on which the wafer 1 is mounted, and the sample stage 3 which has an inner peripheral surface 4a having a diameter smaller than the diameter of the wafer 1 An insulative ring member 4 installed on the wafer 1, and an insulative cover member 5 having an inner peripheral surface 5a corresponding to the side surface 1a of the wafer 1 and the inner peripheral surface 5a having a diameter larger than that of the wafer 1.
A high-frequency power source 7, which is a plasma generating means for generating plasma in the peripheral portion 6 of the wafer 1 placed on the workpiece mounting surface 3a of the sample table 3, and an electrostatic attraction to the workpiece mounting surface 3a of the sample table 3. It is composed of a DC power source 8 which is a voltage applying means for generating a force.

Further, the object mounting surface 4b of the insulating ring member 4 and the surface 2a of the film 2 are formed on the same surface.

Here, the sample table 3 according to this embodiment is formed of, for example, aluminum.

Therefore, the film 2 formed on the object mounting surface 3a, which is the electrostatic attraction surface of the sample table 3, is an oxide of an insulating material, for example, an oxide such as alumina.

The coating 2 is formed by spray-spraying powdery alumina using plasma on the workpiece mounting surface 3a, and its thickness is about 500 μm or less.
However, the film 2 may be formed by depositing it with a CVD device or the like.

The insulating ring member 4 according to this embodiment is also used.
Is formed of a ceramic material such as alumina, and the insulating ring member 4 is press-fitted into a groove or the like provided at a predetermined position of the sample table 3 and fixed by an adhesive 9 or the like. Note that the insulating ring member 4 may be made of quartz or the like as long as it is an insulating material having high heat resistance.

Here, in the semiconductor manufacturing apparatus according to this embodiment, the workpiece mounting surface 4b of the insulating ring member 4 and the film 2 are processed.
And its surface 2a are formed on the same surface by polishing.

That is, the insulating ring member 4 is attached to the sample table 3.
Is attached, and the film 2 is formed on the object-mounting surface 3a of the sample table 3. Then, the object-mounting surface 4b of the insulating ring member 4 and the surface 2a of the film 2 are ground to be the same surface. I do.

The insulating cover member 5 is made of a ceramic material and is installed on the outer peripheral portion of the insulating ring member 4 by a fitting method or the like.
Has an inner peripheral surface 5a corresponding to the side surface 1a.

As a result, displacement of the wafer 1 when it is placed is prevented, and further abnormal discharge at the outer peripheral portion of the sample table 3 is prevented.

The insulating ring member 4 according to this embodiment is used.
Has an inner peripheral surface 4a having a diameter of 4 mm from the diameter of the wafer 1.
The diameter of the outer peripheral surface 4c is about 1 mm larger than the diameter of the wafer 1, and the center of the workpiece mounting surface 3a of the sample table 3 and the insulating ring member 4 are small.
It is installed in a state where the center of the inner peripheral surface 4a is aligned.

Further, the diameter of the inner peripheral surface 5a of the insulating cover member 5 is also formed to be about 1 mm larger than the diameter of the wafer 1, and the insulating cover member 5 has an inner peripheral surface 5 thereof.
The a is abutted against the outer peripheral surface 4c of the insulating ring member 4 to be installed.

The outer peripheral surface 4c of the insulating ring member 4
Does not necessarily have to be formed larger than the diameter of the wafer 1 by about 1 mm.
It suffices that the inner peripheral surface 5a of the insulating cover member 5 prevents the positional displacement of the wafer 1 when the insulating cover member 5 and the insulating cover member 5 are installed.

Further, a high frequency power source 7 which is a plasma generating means and a DC power source 8 which is a voltage applying means are respectively connected to the sample stage 3, the high frequency power source 7 is connected through a capacitor 10, and the DC power source 8 is It is connected through the filter 11.

Here, the capacitor 10 is for preventing the DC current from the DC power source 8 from flowing to the high frequency power source 7 side, and the filter 11 is such that the high frequency from the high frequency power source 7 flows to the DC power source 8 side. This is a high-frequency cutoff circuit that prevents this.

That is, after plasma is generated by the high frequency power source 7, a DC voltage is applied to the sample stage 3 by the DC power source 8 to electrostatically attract the wafer 1.

Next, the semiconductor manufacturing method of this embodiment will be described.

As an example of the semiconductor manufacturing method,
Here, the etching method will be described.

First, the wafer 1, which is an example of the object to be processed, is placed on the object mounting surface 3a of the sample table 3.

At this time, the inner peripheral surface 5a of the insulating cover member 5
Guides the wafer 1 and prevents the wafer 1 from being displaced.

After that, a high frequency power source 7 as a plasma generating means generates plasma in the peripheral portion 6 of the wafer 1 or above the peripheral portion 6.

Then, a DC voltage is applied to the sample stage 3 by the DC power source 8 to electrostatically attract the wafer 1. At this time, the wafer 1 is electrostatically adsorbed and held while the back surface of the outer peripheral portion of the wafer 1 is brought into close contact with the workpiece mounting surface 4b of the insulating ring member 4.

Then, using the plasma, the wafer 1
Etching a predetermined part of

Next, the function and effect obtained by the semiconductor manufacturing method and apparatus of this embodiment will be described.

That is, the insulating ring member 4 having the inner peripheral surface 4a having a diameter smaller than that of the wafer 1 and installed on the sample stage 3, and the inner peripheral surface 5 corresponding to the side surface 1a of the wafer 1.
and an insulating cover member 5 in which the diameter of the inner peripheral surface 5a is formed larger than the diameter of the wafer 1, the workpiece mounting surface 4b of the insulating ring member 4 and the surface 2a of the film 2. Are formed on the same surface, it is possible to reduce the amount of recession of the insulating ring member 4 to the back surface of the outer peripheral portion of the wafer 1.

As a result, the area of the workpiece mounting surface 3a, which is the electrostatic adsorption surface of the sample table 3, can be increased, and the reliability of electrostatic adsorption can be improved.

Further, since the area of the object mounting surface 3a of the sample table 3 can be increased, the cooling area by the contact of the wafer 1 with the object mounting surface 3a can be increased. Therefore, the temperature uniformity of the wafer 1 can be improved.

As a result, the processing characteristics of the wafer 1 can be improved.

Further, since the area of the workpiece mounting surface 3a of the sample table 3 can be increased, the application area of the high frequency power source 7 can be increased.

As a result, the uniformity of processing on the wafer 1 can be improved, and as a result, the processing characteristics of the wafer 1 can be improved.

The film 2 formed on the object mounting surface 3a of the sample table 3 is a film formed by spraying powdery alumina, and the object mounting surface of the insulating ring member 4 is also formed. 4b and the surface 2a of the film 2 are formed on the same surface by polishing, so that when the wafer 1 is held by electrostatic attraction, the back surface of the outer peripheral portion of the wafer 1 is mounted on the insulating ring member 4 to be processed. It can be held in close contact with the surface 4b.

As a result, it is possible to prevent the plasma from wrapping around the back surface of the outer peripheral portion of the wafer 1 (abnormal discharge), and prevent the back surface of the outer peripheral portion of the wafer 1 from being processed.

As a result, the reliability of the sample table 3 can be improved.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the embodiments and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, in the above embodiment, the case where the semiconductor manufacturing apparatus of the present invention is an etching apparatus has been described.
The semiconductor manufacturing apparatus is not limited to an etching apparatus, and may be, for example, a plasma CVD apparatus, a sputtering apparatus, or the like as long as it is a semiconductor manufacturing apparatus that electrostatically holds an object to be processed on a sample stage for processing. It may be a drawing device that does not use the.

Further, the insulating ring member according to the above-mentioned embodiment was press-fitted into a groove or the like provided at a predetermined position of the sample table and fixed by an adhesive agent or the like, but the adhesive agent was not used. It may be fixed only by press fitting.

Although the sample table of the above-mentioned embodiment is not provided with a cooling means for the object to be treated, a gas cooling mechanism for cooling the object to be treated may be installed.

Further, although the plasma generating means according to the above embodiment is a high frequency power source, the high frequency power source may not be connected if another plasma generating means is provided.

Further, in the semiconductor manufacturing apparatus according to the above-mentioned embodiment, the insulating ring member and the insulating cover member are separate members, but as shown in the semiconductor manufacturing apparatus of another embodiment of FIG. Elastic ring member and the insulating cover member are made of the same member to form an integral insulating cover member 12,
The integral type insulating cover member 12 may be incorporated in a predetermined portion of the sample table 3.

The integral insulating cover member 12 in this case is also made of alumina or quartz.

This makes it possible to reduce the number of parts in the semiconductor manufacturing apparatus.

[0069]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.

(1). An insulating ring member having an inner peripheral surface having a diameter smaller than that of the object to be processed and installed on the sample stage, and an inner peripheral surface corresponding to a side surface of the object to be processed, and a diameter of the inner peripheral surface Has an insulating cover member formed to be larger than the diameter of the object to be processed, and the object mounting surface of the insulating ring member and the surface of the film are formed on the same surface, so that the insulating ring member It is possible to reduce the amount of the material to be digged into the rear surface of the outer peripheral portion of the workpiece.

As a result, the area of the sample mounting surface (electrostatic adsorption surface) of the sample table can be increased, and the reliability of electrostatic adsorption can be improved.

(2). Since the area of the sample mounting surface of the sample table can be increased, the cooling area due to contact of the processing object with the processing object mounting surface can be increased,
Thereby, the temperature uniformity of the object to be processed can be improved.

As a result, the processing characteristics of the object to be processed can be improved.

(3). Since the area of the workpiece mounting surface of the sample table can be increased, the application area of the high frequency power source can be increased.

As a result, it is possible to improve the uniformity of processing on the object to be processed, and as a result, it is possible to improve the processing characteristics of the object to be processed.

(4). The film formed on the sample mounting surface of the sample table is a film formed by spraying a powdery insulating material, and the sample mounting surface of the insulating ring member and the film surface are polished. Since they are formed on the same surface, when the object to be processed is held by electrostatic attraction, the back surface of the outer peripheral portion of the object to be processed can be held in close contact with the object mounting surface of the insulating ring member. .

As a result, it is possible to prevent the plasma from flowing around the back surface of the outer peripheral portion of the object to be processed (abnormal discharge), and to prevent the back surface of the outer peripheral portion of the object to be processed. As a result, the reliability of the sample table can be improved.

(5). By forming the insulative ring member and the insulative cover member as an integral member made of the same member, it is possible to reduce the number of parts of the semiconductor manufacturing apparatus.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing an example of the structure of an etching apparatus which is an embodiment of a semiconductor manufacturing apparatus according to the present invention.

FIG. 2 is a partial cross-sectional view showing an example of the structure of an etching apparatus which is another embodiment of the semiconductor manufacturing apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wafer (processing object) 1a Side surface 2 Coating 2a Surface 3 Sample stage 3a Processing object mounting surface 4 Insulating ring member 4a Inner peripheral surface 4b Processing object mounting surface 4c Outer peripheral surface 5 Insulating cover member 5a Inner peripheral surface 6 Peripheral part 7 High frequency power source (plasma generating means) 8 DC power source (voltage applying means) 9 Adhesive agent 10 Capacitor 11 Filter 12 Integrated insulating cover member

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Iwa Natori 3-3, Fujibashi, Ome-shi, Tokyo 2 Hitachi Hitachi Electronics Co., Ltd.

Claims (5)

[Claims] 1. A semiconductor manufacturing method for processing an object to be processed using plasma, wherein the object to be processed is placed on an object mounting surface of a sample table, and the object to be processed is mounted on a peripheral portion of the object to be processed. The plasma is generated, and the object to be processed is electrostatically adsorbed and held in a state in which the outer peripheral back surface of the object to be processed is brought into close contact with the object mounting surface of the insulating ring member installed on the sample stage, and the plasma is generated. A method for manufacturing a semiconductor, characterized in that the object to be processed is processed by using the method. 2. A semiconductor manufacturing apparatus for processing an object to be processed, wherein the object to be processed is held by suction, and a film made of an insulating material is formed on a surface of the object to be processed on which the object to be processed is mounted. A formed sample stand, an insulating ring member having an inner peripheral surface having a diameter smaller than that of the object to be processed, and installed on the sample stand, and an inner peripheral surface corresponding to a side surface of the object to be processed. And an insulating cover member in which the diameter of the inner peripheral surface is formed to be larger than the diameter of the object to be processed, and voltage applying means for generating an electrostatic attraction force on the object mounting surface of the sample table. And a surface of the insulating ring member on which the workpiece is mounted and a surface of the film are formed on the same surface. 3. A semiconductor manufacturing apparatus for processing an object to be processed by using plasma, wherein the object to be processed is held by adsorption and is insulated from an object mounting surface on which the object is mounted. A sample stage on which a film made of a material is formed, an insulating ring member having an inner peripheral surface having a diameter smaller than the diameter of the object to be processed, and installed on the sample stage, and a side surface of the object to be processed. An insulating cover member having a corresponding inner peripheral surface and having a diameter of the inner peripheral surface larger than the diameter of the object to be processed, and the object to be processed placed on the object mounting surface of the sample table. The object mounting surface of the insulating ring member has plasma generating means for generating plasma in the peripheral part of the object, and voltage applying means for generating electrostatic attraction force on the object mounting surface of the sample table. And the surface of the film is formed on the same surface, Semiconductor manufacturing equipment. 4. The semiconductor manufacturing apparatus according to claim 2 or 3, wherein the film is a film formed by spraying a powdery insulating material. 5. The semiconductor manufacturing apparatus according to claim 2, 3 or 4, wherein the workpiece mounting surface of the insulating ring member and the surface of the film are formed on the same surface by polishing. Characteristic semiconductor manufacturing equipment.