JPS63134145A - Electrostatic chuck - Google Patents

Abstract

PURPOSE:To cool a wafer so efficiently, by installing an electristatic chuck electrode in upper and lower surfaces of a tray, impressing DC voltage from an electric conductor of a water cooled electrode, and clamping the tray and the wafer as well as the tray and the water cooled electrode to an electrostatic chuck. CONSTITUTION:The wafer 20 mounted on a tray 19 is conveyed to the inside of a vacuum vessel 1, and mounted on a pin 18 piercing through a flat plate part of a lifting shaft 6 and an electrode 8. And, this lifting shaft 6 is made to go up, and the tray 19 is mounted on the electrode 8, while a peripheral edge of the tray 19 is made contact with a projecting part 2 of the vessel 1 and pressed thereto. Under this state, a conductive spring 14 and an electrostatic chuck electrode 23 of the tray 19 are made contact with each other. At this time, DC voltage is impressed via an electrostatic wire 17, and the wafer 20 is clamped to the tray and, in turn, the tray onto the electrode 8 electrostatically, respectively. Thus, the tray 19 is positively clamped to a water cooled electrode 8, thus positive cooling for the wafer 20 is performable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an electrostatic chuck, and particularly to an electrostatic chuck that improves the adhesion between a tray and a water-cooled electrode.

(Prior art) Conventionally, in vacuum processing equipment such as dry etching equipment, electrostatic chucks have often been used as a means to increase the cooling efficiency of the wafer by bringing the wafer into close contact with the water-cooled discharge electrode when processing the wafer. It is used.

The electrostatic chuck described above attaches an electrostatic chuck electrode coated with an insulating film such as a dielectric material to a water-cooled discharge electrode on which the wafer is fixed, and then applies a DC voltage to the electrostatic chuck electrode. is fixed electrostatically.

(Problem to be solved by the invention) However, since the discharge is stable and uniform etching can be performed, the inventors placed the discharge electrode below the vacuum container and placed the wafer on the top surface of this electrode. We have developed a dry etching device that performs etching by placing trays in close contact with each other. Therefore, due to the presence of the tray, the above conventional electrode cannot be applied as is, and since the tray is present between the water-cooled electrode and the wafer, efficient cooling is required.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide an electrostatic chuck that can efficiently cool a wafer even when an electrode is disposed below and a tray is used. .

[Structure of the invention]

(Means for solving the problems) In order to achieve the above object, the electrostatic chuck according to the present invention has the following features:
Electrostatic chuck electrodes coated with insulating films are provided on the upper and lower surfaces of the tray placed on the upper surface of the water-cooled electrode, respectively, on which the wafer is placed, and the electrodes on the lower surface are provided with electrostatic chuck electrodes coated on the upper surface of the water-cooled electrode. A feature of the electrostatic chuck is that a portion of the electrode is exposed so as to be in contact with a conductor for supplying power to the electrostatic chuck.

(Function) According to the present invention, by providing electrostatic chuck electrodes on the upper and lower surfaces of the tray and applying a DC voltage from the conductor of the water-cooled electrode, the tray and the wafer are fixed by the electrostatic chuck, and Since the tray and the water-cooled electrode are also fixed by the electrostatic chuck, the tray can be reliably brought into close contact with the water-cooled electrode, and therefore the tray can be reliably cooled and the wafer can be efficiently cooled.

(Example) Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 4.

FIGS. 1 and 2 show an embodiment of a dry etching apparatus to which an electrostatic chuck according to the present invention is applied.
A protrusion 2 that protrudes inward is formed at the upper part of the interior of the vacuum vessel 1 whose upper plate is removable, and a shaft supporting member 3 is fixed to the lower surface of the vacuum vessel 1 . An elevating shaft 6 having a through hole 4 in the center and a flat plate portion 5 integrally formed at the upper end is supported on the shaft supporting member 3. An air cylinder 7 is attached to the lower end of the elevating shaft 6. is connected,
By driving this air cylinder 7, the elevating shaft 6 can be moved up and down. An electrode 8 functioning as a cooling plate is fixed to the upper surface of the flat plate portion 5 of the lifting shaft 6, and a cooling water passage 9 is provided inside the electrode 8.
At the center of the electrode 8, there is a cooling water inlet 10 and a cooling water outlet 11 that open on the lower surface and communicate with the cooling water passage 9.
are provided for each. Furthermore, as shown in FIG. 3, an insulating rod 13 into which a conductive bottle 12 is inserted is embedded in the center of the electrode 8.
A conductive spring 14.14, which is connected to the conductive pin 12, is connected to the upper and lower ends of. In addition, a cooling water introduction pipe 15 and a cooling water discharge pipe 16 connected to the introduction port 10 and the discharge port 11 of the electrode 8 are inserted into the through hole 4 of the lifting shaft 6, respectively, and the ends thereof are An electrostatic chuck electric wire 17 that contacts the lower conductive spring 14 is inserted.

Further, on the lower surface of the vacuum container 1, the elevating shaft 6 is provided.
Pins (four in this example) 18, 18, which pass through the flat plate portion 5 and electrodes 8 of A conveyance port 21 is formed.

As shown in FIG.
The upper and lower electrodes 23 are connected through the center of the tray 19, and the center of the lower electrode 23 is exposed to the outside. Further, a DC power source 24 is connected to the electrostatic chuck electric wire 17 via a filter 25. In this embodiment, the wafer 20 placed on the tray 19 is transported by a transport device (not shown) into the vacuum container 1 through the transport port 21, and is placed on the bin 18 as shown in FIG. . Then, the air cylinder 7 is driven to raise the elevating shaft 6, and the tray 19 is placed on the electrode 8. As shown in FIG.
Raise the tray 19 until it comes into contact with the tray 19 and press the tray 19. In this state, the conductive spring 14 and the electrostatic chuck electrode 23 of the tray 19 come into contact, and by applying a DC voltage via the electrostatic chuck wire 17, the wafer 20 is electrostatically placed on the tray 19. At the same time, the tray 19 is electrostatically fixed onto the electrode 8. On the other hand, one chamber is formed above the vacuum container 1 by the protrusion 2 and the tray 19. At this time, the conductive spring 14 is formed to have a biasing force that is easily compressed by the weight of the tray 19. By applying a high voltage to the electrode 8, a discharge is generated on the upper surface of the wafer 20, and the wafer 20 is dry etched.

After etching is completed, lower the lifting shaft 6,
The tray 19 is held on the pins 18.

As a result, the current is no longer applied to the electrode 23 of the tray 19, and the electrostatic chuck is released.

Therefore, in this embodiment, the wafer 20 can be reliably fixed by the electrostatic chuck, and since the tray 19 and the electrode 8 are also brought into close contact with each other by the electrostatic chuck, the cooling water flowing through the cooling water passage 9 in the electrode 8 The wafer 20 can be efficiently cooled by water.

The electrostatic chuck electrode of the tray may be formed by printing an insulating film using a silk screen and forming a metal film as an electrode by electroless plating using a printing technique.

〔Effect of the invention〕

As described above, the electrostatic chuck according to the present invention provides electrostatic chuck electrodes on the upper and lower surfaces of the tray, and applies a DC voltage from the conductor of the water-cooled electrode to attach the tray and the wafer using the electrostatic chuck. In addition to fixing the tray, the tray and water-cooled electrode were also fixed using an electrostatic chuck.
The tray can be reliably brought into close contact with the water-cooled electrode, and therefore the tray can be reliably cooled, and the wafer can be efficiently cooled.

[Brief explanation of the drawing]

1 to 4 each show an embodiment of the present invention, and FIGS. 1 and 2 are longitudinal cross-sectional views, and FIG.
The figure is a longitudinal cross-sectional view of the central portion of the electrode, and FIG. 4 is a longitudinal cross-sectional view of a portion of the tray. DESCRIPTION OF SYMBOLS 1... Vacuum container, 6... Lifting shaft, 8... Electrode, 9... Cooling water passage, 10... Cooling water inlet, 1
1... Cooling water outlet, 12... Conductive pin, 14...
・Conductive spring, 15...Introduction pipe, 16...Discharge pipe, 1
7... Electric wire for electrostatic chuck, 18... Pin, 19...
... Tray, 20... Wafer, 23... Electrostatic chuck electrode, electrostatic chuck power supply. Applicant's agent Sato - Yu Drawing No. 7: (No change in content) Yu 1 Drawing 2 Drawing 4 Drawing procedure amendment December 22, 1986

Claims (1)

[Claims] Electrostatic chuck electrodes coated with insulating films are provided on the upper and lower surfaces of the tray placed on the upper surface of the water-cooled electrode, respectively, on which the wafer is placed, and the electrodes on the lower surface are provided with electrostatic chuck electrodes coated on the upper surface of the water-cooled electrode. An electrostatic chuck characterized in that a part of the electrode is exposed so as to be in contact with a conductor for supplying power to the electrostatic chuck.