JPS60236218A - Device for plasma processing - Google Patents

Abstract

PURPOSE:To stabilize the state of distribution of plasma to attain a uniform thickness of a film and reduction of a deposit and thereby to form a thin film of high quality under high productivity, by a construction wherein a cover absorbing the radiation of a high-frequency output is provided on the back surface of an upper electrode or the like and grounded so as to prevent the occurrence of electric discharge. CONSTITUTION:A wafer 24 is placed on a lower electrode 23, a prescribed reactive gas is supplied to the inside from a supply channel 26, and electride discharge is conducted between said electrode and an upper electrode 22. By a plasma generated by this discharge, a thin film is formed on the surface of the wafer 24. In this construction, the back surface side and circumferential side surface parts of the upper electrode 22 are covered with earth plates 30a and 30b disposed in vicinity thereto. Therefore, a high-frequency output is discharged between the back surface side and circumferential side surface parts of the upper electrode 22, on one side, and the earth plate 30a and the earth tube 30b, on the other, and thus the discharge can be prevented from occurring between this electrode and the inner wall of a vacuum chamber 20.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to plasma treated lids.

[Technical background of the invention and its problems]

Conventionally, a plasma CVD apparatus shown in FIG. 2, for example, has been used as a plasma processing apparatus having a parallel plate electrode structure. In the figure, reference numeral 1 denotes a vacuum chamber, in which a lower electrode 2 and an upper electrode 3 are disposed opposite each other with a predetermined interval.

A wafer 4, which is an object to be processed, is placed on the lower electrode 2. Three upper electrodes are connected to a high frequency power source 5.

Then, a predetermined reaction gas 6 is supplied into the vacuum chamber 1 to set a vacuum state of 10 to 10-3 torr, and high-frequency power is applied between the lower electrode 2 and the upper electrode 3 while rotating the lower electrode 2. is applied to generate plasma. A predetermined thin film is formed on the surface of the wafer 4 by this plasma.

However, in such a plasma processing apparatus 10,
The distance between the upper mold fi3 and the vacuum chamber-1 was narrow, and the distance between the lower mold fj2 and the upper electrode 3 was i? ! If they are equal, a discharge occurs between the vacuum chamber 6-1 and the upper electrode 3. This extra discharge causes variations in high frequency power density and distribution. In order to compensate for the loss due to this variation, it is necessary to increase the high frequency output.

However, there is a problem in that increasing the high frequency output increases the damage caused to the sea urchins. As a result, the distribution of plasma cannot be stabilized, the film thickness varies, and a thin film of good quality cannot be obtained with high productivity.

Further, FIG. 3 shows a plasma processing apparatus used for dry etching. In the figure, reference numeral 11 denotes a vacuum chamber 2-, in which an upper mold riJ2 and a lower electrode 13 are disposed opposite each other at a predetermined interval, similar to the plasma CVD apparatus io described above. 17 Then, plasma is generated by the discharge that occurs between these electrodes 12 and 13, and the Unino I on the lower electrode 13 is generated.
The surface of 4 is etched. In the case of this device as well, discharge occurs between the vacuum chamber A-1r and the upper electrode 12 in the same way as in the above-mentioned device. As a result, the plasma distribution state cannot be stabilized, the etching accuracy deteriorates, and a predetermined pattern width cannot be formed.

[Purpose of the invention]

The present invention makes it possible to stabilize the distribution of plasma, achieve a uniform film thickness, reduce deposits on the walls of the chamber, and form a high-quality thin film with high productivity. The purpose is to provide a plasma processing apparatus that can perform the following steps.

[Summary of the invention]

The present invention emits high frequency output (RF) on the back ring of the upper electrode.
2- is provided to absorb the radiant rayon).
By grounding this and preventing discharge from occurring between it and the inner wall of the chamber, the distribution of plasma is stabilized and the film thickness is uniform, and deposits on the inner wall of the chamber are reduced. This is a plasma processing apparatus that can form high-quality thin films with high productivity.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory diagram showing a schematic configuration of a plasma processing apparatus according to an embodiment of the present invention. In the figure, 20 is a vacuum chamber.
It is. A reactive gas exhaust pipe 2 is formed at the bottom of the vacuum chamber 20. Inside the vacuum chamber 20, an upper electrode 22 and a lower electrode 23 are arranged substantially parallel to each other with a predetermined interval. The upper surface of the lower electrode 23 is provided with a mounting portion for a wafer 24, which is an object to be processed. The lower electrode 23 is rotatably installed by a rotating shaft 25 inserted through the vacuum chamber 20 and led out. The interior of the rotating shaft 25 serves as a reaction gas supply path 26, which communicates with the interior of the vacuum chamber 20. The upper electrode 22Vi is connected to a high frequency introduction shaft 28 via a high frequency introduction shaft 27 inserted through the vacuum chamber A-zo. The back and peripheral side portions of the upper electrode 22 that do not face the lower electrode 23 are covered with a ground plate 90B close to the tl.

The high frequency introduction shaft 27 is also covered with this earth tube 30b and is isolated from the inside of the vacuum chamber 20.

According to the plasma processing apparatus LL configured in this way,
A sea urchin . The plasma generated by this discharge forms a thin film on the surface of the sea urchin 24. Thus, the back side and circumferential side of the upper electrode 22 are covered with ground plates 30IL and 30b adjacent thereto.

For this reason, the back surface side and peripheral side portion of the upper electrode 22, the ground plate 30h, and the ground tube ? By discharging the high-frequency output between Ob and the inner wall of the vacuum chamber 20, it is possible to prevent a discharge from occurring between the inner walls of the vacuum chambers 20 and 20. As a result, it is possible to stabilize the distribution of grains generated by the discharge between the upper electrode 22 and the lower electrode 23, and to form a thin film with a uniform thickness on the wafer 24. Furthermore, by preventing discharge between the vacuum chambers 20 and the vacuum chambers 20, deposits within the vacuum chambers 20 can be reduced 11 and a high quality thin film can be formed. Therefore, productivity can be improved.

In the embodiment, the case of a plasma CVD apparatus has been described, but it goes without saying that the present invention can also be applied to the plasma etching apparatus 44.

〔Effect of the invention〕

As explained above, according to the plasma processing apparatus according to the present invention, it is possible to stabilize the plasma distribution state, achieve a uniform film thickness, and reduce deposits on the inner walls of the chambers, thereby producing a high-quality thin pattern. It is something that can be formed under high productivity

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of a plasma processing apparatus according to an embodiment of the present invention, FIG. 2 is an explanatory diagram showing a schematic configuration of a conventional plasma CVD apparatus, and FIG. FIG. 2 is an explanatory diagram showing a schematic configuration of an etching device. 20...Vacuum chamber-121...Discharge pipe, 22.
Upper electrode, 23. Lower electrode, 24... wafer, 25.
・Rotating shaft, 26... Supply path, 27... High frequency introduction shaft, 28... High frequency power supply part, 29... Insulating gear,
30 colors, 30b...earth plate, 40...delaf processing equipment. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 8 Figure 2 Figure 3

Claims (1)

[Claims] an upper electrode and a lower electrode arranged in a substantially parallel manner with a predetermined interval in a vacuum chamber ζ-; a processing object installation part formed on a surface of the nuclear lower electrode facing the upper electrode; The vacuum chamber Z is formed so as to cover the back side and circumferential side portions of the upper electrode that do not face the lower electrode, and
- a grounding plate connected to the same ground potential at the same ground potential; a high-frequency introduction shaft that is introduced into the vacuum chamber while covered by the grounding plate and connected to the upper electrode; A plasma processing apparatus comprising: a high frequency power source connected to an upper electrode.