JPH05160036A - Plasma producer - Google Patents

Abstract

PURPOSE:To enhance the cleaning workability by a method wherein the inner wall of a plasma production chamber is covered with an insulating wall material for making the plasma distribution even and removing the insulating wall during the cleaning step. CONSTITUTION:In the title plasma producer, the sidewall of a plasma production chamber 25, the periphery of a substrate 2 and the ceiling surface of the chamber 25 are respectively covered with a sidewall cover 21, an exhaust cover 18 and an upper electrode cover 22. Accordingly, all of the plasma producing space is encircled by quartz as an insulator. Since the plasma production chamber 25 is composed of an insulator wall, the plasma distribution is equalized with that in the plasma production chamber 25 composed of a metallic wall. That is, the plasma distribution i.e., the formed film distribution can be improved by entirely encircling the plasma producing space with the quartz.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma generator that forms a thin film on a substrate, which is one of semiconductor manufacturing apparatuses.

[0002]

2. Description of the Related Art A CVD process is one of the manufacturing processes for manufacturing semiconductors to form a desired film on the surface of a silicon substrate, or one of the processes for manufacturing a liquid crystal display device is a film forming process on a glass substrate. is there.

In this method, a substrate is loaded in an airtight processing chamber, high-frequency power is applied between a pair of electrodes provided in the processing chamber, and a reactive gas is supplied into the processing chamber to generate plasma. , A thin film is formed on the surface of a substrate (Chemical Vapor Deposition
on).

In a conventional CVD apparatus, the inside of an airtight processing chamber is
There is one electrode on the surface of which the substrate is installed, and an electrode is provided on the other surface of the airtight processing chamber facing the electrode,
Plasma was generated between the pair of electrodes to perform the CVD process.

The above-mentioned CVD process decomposes gas phase gas molecules and deposits them as a thin film on a substrate. However, the thin film is formed not only on the substrate but also on the electrode facing the substrate and the inner wall of the processing chamber. The film deposited on the electrodes and the inner wall of the processing chamber is peeled off and adheres to the substrate being processed to contaminate the substrate. When the substrate is contaminated with the deposit, it causes serious defects in the film formation of the substrate. In addition, there is a dry etching apparatus that is equipped with a plasma generator, and the dry etching apparatus also has a defect that etching products adhere to the inner wall of the plasma generation chamber and the etching conditions cannot be reproduced. Therefore, conventionally, the processing chamber has been regularly cleaned.

Conventionally, the cleaning work has been troublesome and time-consuming. Therefore, this cleaning work has been a cause of lowering the mobility of the apparatus.

Further, the uniformity of plasma has a great influence on the film formation state, and how to generate uniform plasma is CVD.
It is one of the problems of the device.

[0008]

SUMMARY OF THE INVENTION In view of the above situation, the present invention aims to improve the uniformity of plasma and, at the same time, to improve the workability of cleaning the plasma generating chamber.

[0009]

The present invention is characterized in that the inner wall of the plasma generating chamber is covered with an easily removable insulating wall.

[0010]

[Function] By covering the inner wall of the plasma generation chamber with an insulating wall, the plasma distribution becomes uniform, and at the time of cleaning, the insulating wall is removed and the insulating wall is cleaned to improve the cleaning workability. Improve.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A CVD apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a cross section of a processing chamber of a CVD apparatus according to the present invention.

The present CVD apparatus particularly shows a double chamber structure, and the double chamber structure is suitable for generating a uniform plasma by limiting the plasma generation space. It is said that

An upper electrode holder 4 is provided on the upper surface of the processing chamber 1,
A guide pipe 5 penetrating the upper surface of the processing chamber 1 is provided at the center of the upper electrode holder 4, and an electrode upper plate 6 and an electrode lower plate 7 are provided at the lower end of the guide pipe 5, and the guide pipe 5 and the electrode upper plate are provided. 6. The lower electrode plate 7 is insulated by insulating materials 8, 9, 10, 11.

A gap 12 is formed between the upper electrode plate 6 and the lower electrode plate 7, and the gap 12 communicates with the inside of the guide pipe 5. Further, the lower electrode plate 7 is provided with a required number of supply holes 13.

An inner chamber 15 is provided on the lower surface of the upper electrode holder 4 so as to be vertically separable, and a lower electrode 16 facing the electrode lower plate 7 is provided at the center of the bottom of the inner chamber 15.

An exhaust plate 17 is provided along the periphery of the lower electrode 16, and a quartz exhaust cover 18 is mounted on the upper surface of the exhaust plate 17.

An exhaust groove 39 is formed on the exhaust plate 17 from the upper surface side.
Is formed, and the exhaust groove 39 has a straight portion 39a directed toward the center.
And a zigzag shape formed by a blow-off portion 39b located at the tip of the straight-moving portion and a transverse portion 39c connected to the straight-moving portion 39a, and the inside of the processing chamber 1 is located at the center position of the exhaust groove 39. A through hole 40 communicating with the.

The exhaust lid 18 covers the exhaust groove 39 to form a zigzag-shaped exhaust passage.
8 is provided with an exhaust port 41 at a required position.
Due to the air guide groove 42 formed on the lower surface side of the
And the exhaust groove 39 communicate with each other.

Further, a lower electrode cover 19 made of quartz is placed over the exhaust cover 18 and the lower electrode 16. The lower electrode cover 19 is aligned with a quartz pin 20 embedded in the lower electrode 16.

A quartz side wall cover 21 is provided inside the inner chamber 15, and the side wall cover 21 and the lower electrode cover 1 are provided.
9 means that 1 part is polymerized. An upper electrode cover 22 is provided so as to drop into the upper end step portion of the side wall cover 21 so that a gap is formed between the upper electrode cover 22 and the electrode lower plate 7.

The O-ring 14 is provided along the upper inner peripheral edge of the inner chamber 15, and the O-ring 14 is brought into contact with the upper electrode holder 4 and the side wall cover 21 at the same time, whereby the upper electrode holder 4 and the inner chamber 15 The inner chamber 15 and the side wall cover 21 are hermetically sealed.

The upper electrode cover 22 has a large number of dispersion holes 2
3 is bored, and by supplying a reaction gas from a reaction gas supply pipe 24 provided in the guide pipe 5, through the hollow portion of the guide pipe 5, the gap 12 and the supply hole 13,
The reaction gas is uniformly supplied to the plasma generation chamber 25 through the dispersion holes 23. Further, the gas in the plasma generation chamber 25 is discharged into the processing chamber 1 through the exhaust cover 18 and the exhaust plate 17, and is further exhausted from the processing chamber 1 through the exhaust port 34 provided in the bottom plate 43 of the processing chamber 1. Exhausted.

A lower electrode heating plate 26 that abuts the lower surface of the lower electrode 16 is provided so as to be movable up and down, and the lower electrode heating plate 26 is provided on a pedestal 27 via a spring 28. A plurality of heat reflection plates 38 are provided below the lower electrode heating plate 26 to provide thermal insulation to the lower side of the lower electrode heating plate 26. Further, the pedestal 27 is provided with a pressing pin 29 that comes into contact with the lower surface of the inner chamber 15.

Although not specifically shown, the pedestal 27 is supported by an elevating unit, and the elevating unit supports the inner chamber 15
Is pressed against the upper electrode holder 4 via the pressing pin 29, and the lower electrode heating plate 26 is moved to the spring 2
It is pressed against the lower electrode 16 via 8. Furthermore, the exhaust cover 1
8, the side wall cover 21, and the upper electrode cover 22 to the inner chamber 15
In this state, the lower electrode heating plate 26 is supported and lowered. Wheels 35 are provided in the inner chamber 15, and the inner chamber 15 rides on a rail 36 in a lowered state.

A loading / unloading hole 30 for loading / unloading the substrate 2 is provided on one side surface of the inner chamber 15 and the side wall cover 21, and the loading / unloading hole 30 is opened / closed by a shutter 32 supported by a parallel link 31. The shutter 32 is rotated by the shutter opening / closing device 33.

The shutter opening / closing device 33 will be described.

As described above, the shutter 32 is provided in the inner chamber 15 through the parallel link 31, and the shutter 3
An engaging groove 44 penetrating in the horizontal direction is engraved in 2, and the lower end of the shutter 32 is tapered.

A seal block 45 is provided through the bottom plate 43, and a bearing block 48 is fixedly attached to the upper surface of the bottom plate 43. A lift rod 46 is provided on the seal block 45 in an airtight and slidable manner. 46 slidably penetrates the bearing block 48. A shutter opening / closing cylinder 47 is connected to the lower end of the lift rod 46,
A pressing plate 49 is fixed to the upper end of the lift rod 46. In addition, the pressing plate 49 has a guide rod 5 extending downward.
0 is provided, and the guide rod 50 is slidably fitted in the bearing block 48.

An engaging element 52 is provided on the upper surface of the pressing plate 49 so as to be movable up and down on the pressing plate 49 via a slide pin 51, and the engaging element 52 is biased downward by a spring 55. The engaging element 52 is provided with a pair of engaging pins 53 on the left and right, and the engaging pins 53 are provided in the engaging groove 44.
To play with.

Shutter pressing rollers 54 are provided on the pressing plate 49 at a required pitch (four in this embodiment), and the shutter pressing rollers 54 can contact the taper portion at the lower end of the shutter 32. ..

2 to 4 show a state in which the shutter 32 is closed. To release the shutter 32 from this closed state, the shutter opening / closing cylinder 47 is driven and the pressing force is applied via the lift rod 46. Lower the plate 49. The shutter 32 may be in close contact with the inner chamber 15, but the engagement pin 5 loosely fitted in the engagement groove 44 may be used.
3 pulls down the shutter 32. In this case, since the pull-down force acts on the shutter 32 via the engagement pin 53, excessive force does not act to damage the shutter 32.

The shutter 32 can be closed by driving the shutter opening / closing cylinder 47 to raise the pressing plate 49. The shutter 32 is pushed up via the shutter pressing roller 54, and the shutter 32 seals the loading / unloading hole 30 of the inner chamber 15. Even after the shutter 32 seals the loading / unloading hole 30, the shutter opening / closing cylinder 47 is made to exert a required ascending force, and the shutter 32 is moved through the shutter pressing roller 54 at a plurality of positions in the inner chamber 15.
To uniformly seal the loading / unloading hole 30.

By opening and closing the loading / unloading hole 30 by the shutter opening / closing device 33, the loading / unloading of the substrate 2 necessary for processing the substrate 2 in the plasma generation chamber 25 can be performed.

Although it has been described that the inner chamber 15 descends and rides on the rail 36, the inner chamber 15 is at a right angle to the loading / unloading direction of the substrate 2 along the rail 36 for further cleaning work. It can be pulled out in the direction of the inner chamber 1
5 moves in the horizontal direction, the engagement pin 53 moves in the engagement groove 44, and the engagement between the shutter 32 and the shutter opening / closing device 33 is easily released. Even when the chamber 15 is charged, the shutter 3 is surely attached.
2 and the shutter opening / closing device 33 are engaged.

A communication hole 37 for coupling with another unit is provided at a position facing the carry-in / out hole 30 of the processing chamber 1, and a robot arm (not shown) of a carrier machine is provided through the communication hole 37. ) Goes in and out. The communication hole 37 is opened and closed by a gate valve (not shown).

Thus, with the shutter 32 open, the substrate 2 is loaded into the plasma generation chamber 25, and the lower electrode 16
1 with the shutter 32 closing the loading / unloading hole 30 while supplying the reaction gas from the reaction gas supply pipe 24 to the plasma generating chamber 25, the electrode lower plate 7 and the lower electrode Plasma is generated between 16 and 16 to form a film on the substrate 2.

When the film formation is completed, the shutter opening / closing device 33 opens the loading / unloading hole 30, and the substrate 2 is unloaded from the main CVD apparatus by a transporter (not shown).

As described above, the side wall of the plasma generating chamber 25 is provided by the side wall cover 21, the periphery of the substrate 2 is provided by the lower electrode cover 19, and the exhaust plate 17 is provided by the exhaust cover 18.
Accordingly, the ceiling surface of the plasma generation chamber 25 is covered with the upper electrode cover 22. Therefore, the space in which the plasma is generated is surrounded by quartz, which is an insulator.

FIG. 7 shows the plasma distribution X when the plasma generation chamber 25 is a metal wall and the plasma distribution Y when the plasma generation chamber 25 is an insulator wall. As a result of the experiment, the plasma distribution chamber is shown. It was found that the plasma distribution Y when 25 was an insulator wall was more uniform than the plasma distribution X when the plasma generation chamber 25 was a metal wall. Thus, by enclosing all the space in which plasma is generated with quartz as in this embodiment, it is possible to improve the plasma distribution, that is, the film formation distribution.

Further, the side wall cover 21 and the lower electrode cover 1
9, the exhaust cover 18 and the upper electrode cover 22 are simply stacked up without using bolts or other clamping means, so assembly and disassembly are extremely easy.
Cleaning work is significantly easier.

Although the above embodiment has been described with respect to the CVD apparatus having the double chamber structure, it is needless to say that the present invention can also be applied to a normal CVD apparatus having the single chamber structure. Further, a dry etching apparatus can be similarly implemented, and quartz is mentioned as the insulating material, but needless to say, alumina, zirconia, magnesia or the like may be used.

[0043]

As described above, according to the present invention, the plasma distribution can be made uniform, the film formation quality can be improved, the cleaning workability can be improved, and the operating rate of the apparatus can be improved. ..

[Brief description of drawings]

FIG. 1 is a sectional view of a CVD apparatus according to an embodiment of the present invention.

FIG. 2 is a front view of a shutter opening / closing device in the present CVD device.

FIG. 3 is a plan view of the front shutter opening / closing device.

FIG. 4 is a side view of the front shutter opening / closing device.

FIG. 5 is a sectional view showing an exhaust structure provided in an inner chamber of the present CVD apparatus.

FIG. 6 is a plan view showing the same exhaust structure.

FIG. 7 is a diagram showing plasma distribution in a CVD processing chamber.

[Explanation of symbols]

 18 Exhaust lid 19 Lower electrode cover 21 Side wall cover 22 Upper electrode cover 25 Plasma generation chamber

Front Page Continuation (72) Inventor Tomohiko Takeda 2-3-13 Toranomon, Minato-ku, Tokyo Kokusai Electric Inc. (72) Inventor Ryoji 3300 Hayano, Mobara-shi, Chiba Hitachi Ltd.

Claims (1)

[Claims] 1. A plasma generator in which the inner wall of the plasma generating chamber is covered with an easily removable insulating wall.