JP3976902B2 - Plasma processing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vacuum processing apparatus using ICP (Inductive Coupled Plasma), and more particularly to a plasma introduction window structure thereof.
[0002]
[Prior art]
In a conventional vacuum processing apparatus using ICP, as shown in FIG. 3, a quartz window 21 made of a quartz plate or an alumina plate used in the ICP introduction portion (in this specification, it may be made of an alumina plate). (Referred to as a quartz window) is disposed on the upper lid 22 of the vacuum container via a sealing material 23. The flat plate heater 24 for heating the quartz window 21 is installed on the quartz window 21 and several places on the outer periphery thereof are fastened together with the quartz window 21 by the fixing block 25, so that the quartz window 21 is pressed into the two. Are closely attached.
[0003]
Further, as shown in FIG. 4, the coil disposed in the upper part of the quartz window 21 includes a single spiral coil 26, and an insulating plate 27 is interposed between the spiral coil 26 and the flat plate heater 24. The spiral coil 26 is configured to press the flat plate heater 24 against the quartz window 21 through the insulating plate 27.
[0004]
[Problems to be solved by the invention]
However, in the above-described conventional configuration, when the inside of the vacuum chamber is evacuated, the central portion of the quartz window 21 is slightly bent downward, the quartz window 21 is separated from the flat plate heater 24, and the thermal uniformity of the quartz window 21 is not good. was there. In order to solve this problem, the flat plate heater 24 is pressed against the quartz window 21 by the spiral coil 26 as described above. However, the flat plate heater 24 cannot be sufficiently exerted and the flat plate heater 24 is also bent by the bending of the quartz window 21. There is a problem that the contact with the insulating plate 27 becomes non-uniform and the insulating plate 27 is frequently damaged by the thermal stress.
[0005]
It is also conceivable to provide means for pressing the central portion of the flat plate heater 24 toward the quartz window 21, but since the gap between the single spiral coils 26 is narrow, a mechanism for pressing the flat plate heater 24 at the central portion is provided. If attached, problems such as non-uniform plasma density occur.
[0006]
In view of the above-described conventional problems, the present invention provides a plasma processing apparatus provided with a plasma introduction window that can ensure close contact between a quartz window and a heater even when the vacuum chamber is evacuated to improve the thermal uniformity of the quartz window. It is intended to provide.
[0007]
[Means for Solving the Problems]
In the present invention, a heater is disposed on the upper surface of a quartz window, a multiple spiral coil is disposed on the upper portion thereof, and the heater is pressed toward the quartz window in a position avoiding the multiple spiral coil near the center of the heater. Thus, even if the quartz window is bent by evacuation, the adhesion between the quartz window and the heater can be ensured, and the thermal uniformity of the quartz window can be improved. In addition, since the insulating plate on the conventional heater is not required, the problem of breakage of the insulating plate due to thermal stress caused by non-uniform conduction of heat from the heater can be eliminated.
[0008]
In addition, the upper lid of the vacuum vessel is divided into two parts, and a quartz window is arranged on the lower part of the upper lid via a sealant. A heater is suspended from the lower surface of the upper part of the upper lid, and the outer periphery of the heater and the quartz window If a compression spring that presses the heater toward the quartz window is arranged near the center avoiding the multiple spiral coils arranged at the top, the outer periphery and the vicinity of the center of the heater are pressed against the quartz window by the compression spring. The entire surface of the heater can be securely and uniformly adhered to the quartz window without restricting the outer peripheral portion of the heater, and the thermal uniformity can be further improved.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of an ICP type plasma processing apparatus of the present invention will be described with reference to FIGS. The ICP type plasma processing apparatus generates plasma in a vacuum vessel by applying a high frequency voltage to a discharge coil (multiple spiral coil) 11.
[0010]
In FIG. 1, the upper lid 3 of the vacuum vessel is divided into two upper and lower parts, and is composed of an upper lid lower portion 4 and an upper lid upper portion 5. It is installed via the sealing material 2.
[0011]
Reference numeral 6 denotes a flat plate heater, which is made thicker by increasing the thickness of an insulator made of mica or the like above and below the internal metal heater element. The flat plate heater 6 is attached to the lower surface of the upper lid upper part 5 in a suspended state. Specifically, the outer peripheral portion of the flat plate heater 6 is mounted in a suspended state by a bolt 7 and is pressed and urged downward by a compression spring 8. In addition, a lower end portion of a guide shaft 9 that extends upward is coupled near the center of the flat plate heater 6, and the guide shaft 9 is pressed and urged downward by a compression spring 10. The bolt 7 and the guide shaft 9 are made of alumina or covered with an insulating cover such as alumina, and the bolt 7 and the guide shaft 9 are formed on the lower surface of the flat heater 6 so that the heads of the bolt 7 and the guide shaft 9 are accommodated inside. A counterbore is formed.
[0012]
A multiple spiral coil 11 as shown in FIG. 2 is disposed above the flat heater 6, and the guide shaft 9 and the compression spring 10 are disposed avoiding the multiple spiral coil 11.
[0013]
According to the above configuration, even if the quartz window 1 is bent due to evacuation in the vacuum vessel, the outer peripheral portion and the center of the flat plate heater 6 are pressed against the quartz window 1 by the compression reaction force of the compression springs 8 and 10. Thus, the quartz window 1 and the flat plate heater 6 are kept in close contact with each other. As described above, the adhesion between the quartz window 1 and the flat plate heater 6 is improved, and the thermal uniformity of the quartz window 1 can be increased.
[0014]
Further, since it is not necessary to provide the multiple spiral coils 11 with the function of pressing the flat plate heater 6 against the quartz window 1, the multiple spiral coils 11 and the flat plate heater 6 can be separated from each other. Can be eliminated, and the problem of breakage of the insulating plate 27 due to thermal stress caused by non-uniform conduction of heat from the flat heater 6 can be eliminated.
[0015]
【The invention's effect】
According to the present invention, as described above, the heater is disposed on the upper surface of the quartz window, the multiple spiral coils are disposed on the upper portion thereof, and the heater is disposed at a position near the center of the heater so as to avoid the multiple spiral coils. Since the means for pressing the quartz window is disposed, even if the quartz window is bent by evacuation, the quartz window and the heater have good adhesion, and the thermal uniformity of the quartz window can be improved. In addition, since the insulating plate that has been conventionally disposed on the heater is not necessary, the problem of breakage of the insulating plate can be eliminated.
[0016]
In addition, the upper cover of the vacuum vessel is divided into two parts, and a quartz window is disposed on the lower part of the upper cover through a sealing material. If a compression spring that presses the heater toward the quartz window is arranged near the center avoiding the multiple spiral coils arranged at the top, the outer periphery and the vicinity of the center of the heater are pressed against the quartz window by the compression spring. The heat uniformity can be improved by reliably and uniformly adhering the entire surface of the heater to the quartz window.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a schematic configuration of an embodiment of a plasma processing apparatus of the present invention.
FIG. 2 is an explanatory diagram of multiple spiral coil shapes in the embodiment.
FIG. 3 is a longitudinal sectional view showing a schematic configuration of a conventional plasma processing apparatus.
FIG. 4 is an explanatory diagram of a single spiral coil shape in a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Quartz window 2 Sealing material 3 Upper cover 4 Upper cover lower part 5 Upper cover upper part 6 Flat heater 8 Compression spring 10 Compression spring 11 Multiple spiral coils

Claims (2)

A heater is arranged on the upper surface of the quartz window, a multiple spiral coil is arranged on the upper part, and a means for pressing the heater toward the quartz window is arranged at a position near the center of the heater avoiding the multiple spiral coil. A plasma processing apparatus. The upper lid of the vacuum vessel is divided into two parts, and a quartz window is placed on the lower part of the upper lid via a sealant. A heater is suspended from the lower surface of the upper part of the upper lid. A plasma processing apparatus, wherein a compression spring that presses a heater toward a quartz window is disposed near a center avoiding a plurality of spiral coils.

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