JPH09232098A - Plasma processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate a stable plasma by forming a belt-like electrode positioned in the uppermost stage as a first electrode connected to a high frequency power source, and arranging a second electrode connected to the earth in the lowest stage. SOLUTION: One end of a belt-like electrode 11 is fixed to a fastening installing part 3a through an conductor 7, and one end of a belt-like electrode 12 is fixed to a fastening installing part 4b through a conductor 10, and one end of a belt-like electrode 13 is fixed to a fastening installing part 3c through a conductor 7, and one end of a belt-like electrode 14 is fixed to a fastening installing part 4d through a conductor 10, respectively. Here, since the conductor 7 of the fastening installing part 3a and the conductor 7 of the fastening installing part 3c are connected to each other through a small width part 7a, the belt-like electrode 11 and the belt-like electrode 13 are put in equal electric potential, and constitute a first electrode by being connected to a high frequency power source, and the belt-like electrode 12 and the belt-like electrode 14 are grounded, and constitute a second electrode to generate plasma between it and the first electrode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus used for etching a film formed on the surface of a semiconductor wafer or the like and for deposition or the like.

[0002]

2. Description of the Related Art As a plasma processing apparatus for etching a film on the surface of a semiconductor wafer or the like, a first electrode connected to a high-frequency power source is provided around a chamber made of quartz or the like.
It is known to provide a second electrode for generating plasma with this electrode.

Here, in the plasma processing apparatus, the place where plasma is mainly generated is a place where the first electrode and the second electrode are closest to each other. Since the electrode has a half-cylindrical shape, the locations where plasma is generated are two linear regions extending vertically along the chamber.

If the plasma generation region is two linear regions, the plasma generated in the chamber will not be uniform. Therefore, as disclosed in JP-A-6-1322501, the first electrode Also, there is a configuration in which the second electrode has a comb-teeth shape and is arranged on the outer periphery of the chamber such that one convex portion enters the other concave portion.

[0005]

As described above, the first
If the shape of the electrode and the shape of the second electrode are comb-teeth, almost the entire outer peripheral portion in the chamber can be used as the plasma generation region. However, in the case of comb-shaped electrodes, it is necessary to accurately position and fix the convex portion of one electrode to the concave portion of the other electrode so that the gap between the electrodes is constant. There is no means for stably fixing the thin electrode to a predetermined position on the outer peripheral surface of the cylindrical chamber for a long period of time.

[0006]

In order to solve the above problems, a first invention of the present application is to provide a first electrode connected to a high frequency power source on the outer periphery of a chamber having a substantially cylindrical shape with an upper end closed, and a first electrode. A first electrode and a second electrode, wherein the first electrode and the second electrode are provided with a second electrode connected to a power source having a lower frequency than the high-frequency power source or a ground to generate plasma between the first electrode and the first electrode. Each consisting of multiple strip electrodes,
Further, the strip electrodes forming the first electrode and the strip electrodes forming the second electrode are alternately arranged in a vertical direction with a gap between each other, and each strip electrode is wound at a position where the strip electrode is wound about half around the outer circumference of the chamber. Both ends thereof are fixed to a pair of insulators arranged outside the chamber, and the conductors attached to the insulators connect the strip electrodes forming the first electrode and the strip electrodes forming the second electrode to each other. I decided to do it.

According to a second invention of the present application, in the above-described plasma processing apparatus, the number of insulators arranged outside the chamber is one, and the strip electrodes constituting the first electrode and the second electrode are the outer periphery of the chamber. It was wound around one round to be fixed to the one insulator.

In the above first and second inventions,
Position the strip electrodes that make up the first electrode at the top,
Alternatively, a third electrode connected to the ground may be provided at the bottom.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 is an overall perspective view in which two plasma processing apparatuses according to the present invention are provided side by side, and one plasma processing apparatus is disassembled, and FIG. 2 is a view showing a state in which an electrode is attached to a chamber, FIG. (A) and (b)
[Fig. 3] is a perspective view of an insulator for fixing electrodes.

The chamber 2 of the plasma processing apparatus 1 is made of synthetic quartz or the like, and its shape is a substantially cylindrical shape (bell jar type) with its upper end closed. Lower part of chamber 2
The inside of b is the processing space.

A pair of columnar insulators 3 and 4 made of alumina, resin, or the like are vertically arranged at opposite positions outside the small-diameter upper chamber 2a.

The columnar insulator 3 has four fastening portions 3 with ribs 5.
a, 3b, 3c, 3d, and mounting holes 6 are formed in the respective fastening portions, and the first fastening portion 3a and the third fastening portion 3c are made of an aluminum plate, a copper plate, or the like. The conductor 7 is fitted. The middle narrow width portion 7a of the conductor 7 is the fastening portion 3 of the second stage.
It is electrically insulated from the side surface through the rear surface side of b.

The columnar insulator 4 is defined by ribs 8 into four fastening portions 4a, 4b, 4c and 4d, and a mounting hole 9 is formed in each fastening portion to fix the second stage fastening. A conductor 10 made of an aluminum plate, a copper plate, or the like is fitted to the portion 4b and the fourth-stage fastening portion 4d. The small width portion 10a in the middle of the conductor 10 passes through the back surface side of the fastening portion 4c of the third step and is electrically insulated from the side surface. Further, the extension 10 is provided at the lower end of the conductor 10.
b is provided.

Then, the outer circumference of the chamber is wound about half around the side faces of the first-stage fastening portions 3a, 4a of the columnar insulator 3 and the columnar insulator 4 to fasten the two strip electrodes 11, 11. ing.

Further, similarly, the second stage fastening portions 3b,
Two strip-shaped electrodes 12, 12 are fixed to the side surface of 4b, and two strip-shaped electrodes 13, 1 are fixed to the side surfaces of the third-stage fixing portions 3c, 4c.
3, the two strip electrodes 14, 14 are fixed to the side surfaces of the fourth-stage fixing portions 3d, 4d, and the fourth-stage fixing portion 3 is fixed.
Third strip electrodes 15, 15 are fixed to the side surfaces of d, 4d. The strip-shaped electrode 1 is also provided on the outer periphery of the lower chamber 2b.
6 is wound, and the strip electrode 16 is grounded.

Here, one end of the strip electrode 11 is fixed to the fixing portion 3a via the conductor 7 with a screw, and one end of the strip electrode 12 is fixed to the fixing portion 4b via a conductor 10 with a screw.
One end of the strip electrode 13 is fixed to the fastening portion 3c via the conductor 7 with a screw, and one end of the strip electrode 14 is fixed to the fastening portion 4d via a conductor 10 with a screw.

The conductor 7 of the fastening portion 3a and the fastening portion 3c
Since it is connected to the conductor 7 of 1 through the small width portion 7a,
The strip electrode 11 and the strip electrode 13 are equipotential, and the strip electrode 11 and the strip electrode 13 are connected to a high frequency power source through the bifurcated electrode plate 17, and the conductor 10 of the fastening portion 4b is connected.
And the conductor 10 of the fastening portion 4d are connected via the small width portion 10a, the strip electrodes 12 and the strip electrode 14 are at the same potential, and the strip electrodes 12 and 14 form the bifurcated electrode plate 18. Grounded through. The strip electrode 15 is grounded via the extension 10 b of the conductor 10 and the electrode plate 19.

As described above, the strip electrodes 11 and 13 are connected to a high frequency power source to form a first electrode, and the strip electrodes 12 and 14 are grounded to be connected to the first electrode. A second electrode for generating plasma is formed.
It is also possible to connect the strip electrodes 12 and 14 to a power source having a lower frequency than the high frequency power source to which the strip electrodes 11 and 13 are connected, without grounding.

FIG. 4 is a perspective view of a plasma processing apparatus according to another embodiment, and FIG. 5 is a view showing a state in which the electrodes of the plasma processing apparatus shown in FIG. 4 are attached to a chamber. Although two columnar insulators are used to fix the ends of the strip electrodes, in this embodiment,
The strip-shaped electrodes 21, 22, 2
Both ends of 3, 24 are fixed.

That is, the columnar insulator 20 is divided into four by the ribs 26.
The two fixing portions 20a, 20b, 20c, and 20d are defined, and mounting holes 29 are formed in each fixing portion, and the conductors common to the first-stage fixing portion 20a and the third-stage fixing portion 20c. 27, and the second stage fastening portion 20b and the fourth stage fastening portion 20
A common conductor 28 is fitted to d, and the conductor 27 has a connecting small width portion 27a, and the conductor 28 has a connecting small width portion 28a.
An extension 28b is provided in addition to a.

Then, the strip-shaped electrodes 21 that wind around the outer circumference of the chamber about one turn are fastened to both side surfaces of the fastening portion 20a of the first stage of the columnar insulator 20 via the conductor 27, and the fastening of the second stage is performed. Conductors 28 insulated from the conductor 27 on both sides of the attachment portion 20b
The strip-shaped electrode 22 is fixed via the
The strip-shaped electrodes 23 are fixed to both side surfaces of the conductor 4 through the conductors 27,
The strip-shaped electrode 24 is fixed to both side surfaces of the fastening portion 20d of the tier via the conductor 28, and further, the third electrode is extended to the side surfaces of the fastening portion 20d of the fourth tier via the extension portions 28b of the conductor 28. Strip electrode 25
It is fastened.

Also in this embodiment, similarly to the above-mentioned embodiments, the strip-shaped electrode 21 and the strip-shaped electrode 23 are equipotential, and constitute the first electrode connected to the high frequency power source, and the strip-shaped electrode 22 and The strip-shaped electrode 24 becomes equipotential and constitutes a second electrode for generating plasma with the first electrode.

In the above embodiments, four strip electrodes are provided, but the number of strip electrodes is arbitrary.
The shape of the chamber is not limited to the shape shown in the figure, and any shape may be used such that the diameters of the upper portion and the lower portion are substantially the same.

[0024]

As described above, according to the present invention, the first electrode connected to the high frequency power source and the second electrode for generating plasma between the first electrode are provided on the outer circumference of the chamber. In the provided plasma processing apparatus, each of the first electrode and the second electrode is composed of a plurality of strip electrodes.
In addition, the strip electrodes that form the first electrode and the strip electrodes that form the second electrode are alternately arranged in the up-down direction with a gap between each other, and the strip electrodes are wound around the outer circumference of the chamber by approximately half or one turn. At that, the ends are fixed to an insulator arranged outside the chamber, and the strip electrodes forming the first electrode and the strip electrodes forming the second electrode are made of a conductor attached to the insulator. Therefore, the gap between the first electrode and the second electrode for uniformly generating plasma can be kept constant for a long period of time.

Particularly, if the strip-shaped electrodes are fixed at two places as in the invention described in claim 1, the electrodes are fixed more securely, and the strip-shaped electrodes are fixed as in the invention described in claim 2. If the electrodes are fixed at one place, the structure will be simple and the fixing work will be easy.

Further, by providing the strip-shaped electrode located at the uppermost stage as the first electrode connected to the high frequency power source and providing the third electrode connected to the ground at the lowermost stage, stable plasma is generated. You can

[Brief description of drawings]

FIG. 1 is an overall perspective view showing an exploded part of a plasma processing apparatus according to the present invention.

FIG. 2 is a diagram showing a state where an electrode is attached to a chamber.

3 (a) and 3 (b) are perspective views of an insulator for fixing electrodes.

FIG. 4 is a perspective view of a plasma processing apparatus according to another embodiment.

5 is a diagram showing a state in which electrodes of the plasma processing apparatus shown in FIG. 4 are attached to a chamber.

[Explanation of symbols]

1 ... Plasma processing apparatus, 2 ... Chamber, 3, 4, 20
... Columnar insulators 3a, 3b, 3c, 3d, 4a, 4b,
4c, 4d, 20a, 20b, 20c, 20d ... Fastening part, 7, 10, 27, 28 ... Conductor, 11, 13, 21,
23 ... Strip-shaped electrodes constituting the first electrode, 12, 14, 2
2, 24 ... Strip electrodes constituting the second electrode, 15, 25
... Third strip electrode.

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[Procedure amendment]

[Submission date] December 4, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction contents]

The conductor 7 of the fastening portion 3a and the fastening portion 3c
Since it is connected to the conductor 7 of 1 through the small width portion 7a,
The strip electrode 11 and the strip electrode 13 have the same potential, and the strip electrode 11 and the strip electrode 13 have the same potential.
Connect the cable for high frequency application to the screw hole 6 in 3a.
You. In addition, the conductor 10 of the fastening portion 4b and the conductor 10 of the fastening portion 4d
, And the strip-shaped electrode 12 are equipotential, and the strip-shaped electrode 12 and the strip-shaped electrode 14 are grounded via the bifurcated electrode plates 17 and 18. . The strip electrode 15 is grounded via the extension 10 b of the conductor 10 and the electrode plate 19.

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] Fig. 1

[Correction method] Change

[Correction contents]

FIG.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location H01L 21/31 H01L 21/302 B (72) Inventor Kaoru Sakamoto 150 Nakamaruko Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture Tokyo Ohka Kogyo Co., Ltd.

Claims (4)

[Claims] 1. A first electrode connected to a high-frequency power source on the outer periphery of a chamber having a substantially cylindrical shape with its upper end closed, and a first electrode connected to the first electrode to generate plasma between the first electrode and the high-frequency power source. In a plasma processing apparatus provided with a second electrode connected to a low-frequency power source or ground, the first electrode and the second electrode each include a plurality of strip electrodes,
Further, the strip electrodes forming the first electrode and the strip electrodes forming the second electrode are alternately arranged in the vertical direction with a gap therebetween, and the strip electrodes are wound around the outer circumference of the chamber in a substantially semicircular position. Both ends thereof are fixed to a pair of insulators arranged outside the chamber, and the strip electrodes forming the first electrode and the strip electrodes forming the second electrode are formed by the conductors attached to the insulator. A plasma processing apparatus, which is connected. 2. A first electrode, which is connected to a high frequency power source, is provided on the outer periphery of a chamber having a substantially cylindrical shape with an upper end closed, and a plasma is generated between the first electrode and the first electrode, which is higher than the high frequency power source. In a plasma processing apparatus provided with a second electrode connected to a low frequency power source or ground, each of the first electrode and the second electrode is composed of a plurality of strip electrodes.
Further, the strip electrodes forming the first electrode and the strip electrodes forming the second electrode are alternately arranged in the up-down direction with a gap between each other, and each strip electrode has an outer circumference of the chamber of about 1 mm.
At both ends of the spirally wound position, both ends thereof are fixed to a single insulator arranged outside the chamber, and the conductors attached to the insulator make up the strip-shaped electrodes forming the first electrode and the second electrode. A plasma processing apparatus characterized in that strip-shaped electrodes forming electrodes are connected to each other. 3. The plasma processing apparatus according to claim 1, wherein the strip-shaped electrode located at the uppermost stage constitutes the first electrode. 4. The plasma processing apparatus according to claim 1 or 2, wherein a third electrode connected to ground is provided in the lowermost stage.