JPH04147643A - Vacuum coupler with built-in discharge preventing contact, pallet, and method of feeding power to pallet - Google Patents

Abstract

PURPOSE:To prevent glow discharge without deteriorating the vacuum degree of a vacuum container by communicating a feeder connected with a contact provided on a contact cover in an opening with the opening and providing a vacuum pipeline connected with the contact cover. CONSTITUTION:The coupler is provided with a contact cover 9, which has an opening 16, a contact 6 provided on the contact cover 9 through a contact pressing spring 7 in the opening 16, feeder 11 electrically connected with the contact 6 and a vacuum pipeline 10 connected with the contact cover 9 by communicating with the opening 16, and the feeder 11 is provided in the vacuum pipeline 10. When an exhaust system for a vacuum chuck is connected with the vacuum pipeline 10 for the vacuum chuck to exhaust air, a wafer 1 is sucked on the surface of a pallet 2, and when a certain time is passed, the vacuum degree in the opening 16 in the contact cover 9 and in the vacuum pipeline 10 for the vacuum chuck becomes higher than the vacuum degree which easily causes glow discharge. Then, a voltage to apply on an electrostatic chuck contact 5 is increased to the desired value and a vacuum container is started to be vacuum.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a vacuum joint with a built-in discharge prevention contact, a pallet, and a method of supplying power to the pallet.

[Related technology] The second pallet with a built-in vacuum chuck/electrostatic chuck that makes it possible to hold wafers with good flatness
The technology shown in the figure has been proposed (Japanese Patent Application No. 2-37799
issue).

By the way, in this technology, a vacuum chuck and an electrostatic chuck are operated together in the atmosphere to evacuate the atmosphere without changing it. In the process of drawing the vacuum, the vacuum range (several torr to 0.01 torr) is likely to cause glow discharge.
torr). However, since a high voltage of several hundred volts is applied to the electrostatic chuck inside the pallet,
When passing through this vacuum area, close to the contacts, terminals, feeder line 11, etc. exposed in the vacuum container (second
Glow discharge occurs in the area shown by hatching in the figure.

When glow discharge occurs, the applied voltage decreases, making it ineffective as an electrostatic chuck, and further causing failure of the high-voltage power supply circuit.

Therefore, it is necessary to take certain measures to prevent glow discharge from occurring.

Therefore, attempts have been made to take measures against electric discharge, such as using a ceramic welded coated wire or the like for the power supply line 11 and molding the connecting portion between the through terminal 13 and the power supply line 11 with an epoxy filler or the like. Also, since it is not possible to mold parts that must be attached and detached, such as the contacts 6 at the connection between the pallet 2 and the power supply line 11, a contact cover 9 is provided to prevent glow discharge as shown in FIG. An attempt is made to use the attached contact 6.

However, in the technique shown in FIG. 2 or 3, outgas from the filler 15 and the welded coating mold #s11 is directly released into the vacuum container, resulting in a decrease in the vacuum degree of the vacuum container and contamination.

In addition, in the discharge prevention method shown in FIG. 3, the contacts 6 must be covered without any gaps, but in this case, the inside of the contact cover 9 becomes a closed space 17, and this closed space 17 does not contain air. is trapped. When the atmosphere is trapped inside, stress is applied to the back of the pallet 2 due to the pressure difference between the inside of the vacuum container and the closed space 17, and leakage gradually occurs from the closed space 17, causing a decrease in the degree of vacuum inside the vacuum container. becomes.

[Problems to be Solved by the Invention] The present invention has been made to solve the above problems.

SUMMARY OF THE INVENTION An object of the present invention is to provide a vacuum joint with a built-in discharge prevention contact, a pallet, and a method for supplying power to the pallet, which allows a vacuum chuck/electrostatic chuck to function without causing glow discharge.

SUMMARY OF THE INVENTION An object of the present invention is to provide a vacuum joint with a built-in discharge prevention contact, a pallet, and a method for supplying power to the pallet, without reducing the vacuum degree of the vacuum vessel or contaminating the inside of the vacuum vessel.

SUMMARY OF THE INVENTION An object of the present invention is to provide a vacuum joint and a pallet with built-in discharge prevention contacts that allow easy attachment and detachment of a power supply line.

Therefore, the present invention can be applied to, for example, a semiconductor manufacturing apparatus such as an electron beam lithography apparatus, and contributes to improving accuracy and simplifying the mechanism.

[Means to solve the problem]

A first aspect of the present invention for solving the above-mentioned problems is to provide a contact cover having an opening, a contact attached to the contact cover via a biasing means within the opening, and an electrical connection to the contact. A vacuum joint with a built-in discharge prevention contact, comprising a connected power supply line and a vacuum pipe connected to the contact cover in communication with the opening, and the power supply line is disposed within the vacuum pipe. exists in

A second gist of the present invention is a pallet incorporating a vacuum chuck and an electrostatic chuck, characterized in that the vacuum chuck and the electrostatic chuck have a contact point for the electrostatic chuck near the exhaust port of the groove for the vacuum chuck. Exists in a palette that has a built-in.

The third gist of the present invention is a built-in vacuum chuck and electrostatic chuck characterized in that power is supplied for the electrostatic chuck after the part that is likely to cause glow discharge is brought to a higher degree of vacuum than the degree of vacuum that is likely to cause glow discharge. There is a method for feeding power to the pallet.

A fourth aspect of the present invention is a contact cover having an opening, a contact attached to the contact cover via a biasing means within the opening, and a power supply line electrically connected to the contact. A vacuum joint with a built-in discharge prevention electrode, which has a vacuum pipe connected to the contact cover in communication with the opening, and the power supply line is arranged inside the vacuum pipe, is placed near the exhaust port of the vacuum chuck groove. A pallet that is connected to a pallet having contacts for an electrostatic chuck, and supplies power to the electrostatic chuck after the vacuum piping is brought to a high vacuum (higher than the vacuum level where glow discharge is likely to occur in the vacuum piping). Exists in the Electricity Supply Act.

[Function] In a vacuum/electrostatic chuck, the vacuum chuck is first activated to secure the wafer while the vacuum container is at atmospheric pressure, and after the vacuum chuck has stabilized the wafer, the electrostatic chuck is activated to secure the wafer. Once the tank has stabilized, start evacuating the vacuum container.

In the present invention, before the electrostatic chuck is operated, the part where glow discharge is likely to occur is brought to a higher vacuum level than the vacuum level where glow discharge is likely to occur, and then the electrostatic chuck is powered, thereby preventing glow discharge. can do.

As one means for making such a chuck method possible, the present invention provides a joint in which a power supply line for an electrostatic chuck is arranged in a vacuum piping for a vacuum chuck, and also provides a joint in which a power supply line for an electrostatic chuck is arranged in a vacuum pipe for a vacuum chuck. A pallet having electrostatic chuck contacts nearby is provided.

The power supply contact of the pallet according to the present invention is covered with the contact cover of the vacuum joint according to the present invention, the vacuum joint is connected to the pallet, and the inside of the vacuum piping is brought to a high vacuum higher than the vacuum level where glow discharge is likely to occur. If power is supplied to the electrostatic chuck after this, glow discharge can be prevented.

Furthermore, if the vacuum joint according to the present invention and the pallet are used in combination as described above, there is no need for a filler, and the outgas from the weld-coated wire is not directly released into the vacuum container, so the vacuum level of the vacuum container is No deterioration or pollution occurs.

[Example] Embodiments of the present invention will be described in detail below based on the drawings.

FIG. 1 is a block diagram of an embodiment. In FIG. 1, 1 is a wafer, 2 is a pallet, 3 is a groove for a vacuum chuck, 4 is an electrode for an electrostatic chuck, 5 is an upper contact, 6 is a lower contact, 7 is a contact presser spring serving as a biasing means, and 8 0 ring, 9 contact cover (insulator), 10 vacuum piping for vacuum chuck, 11
12 is a vacuum container wall, 13 is a through terminal,
16 is an opening.

The vacuum joint of this example includes a contact cover 9 having an opening 16, a contact 6 attached to the contact cover 9 via a contact presser spring 7 within the opening 16, and a power supply electrically connected to the contact 6. +tllll and a vacuum pipe 10 connected to the contact cover 9 in communication with the opening 16, and the supply 1 and the line 11 are arranged 1° inside the vacuum pipe.

On the other hand, the pallet of this example has an electrostatic chuck contact 5 near the exhaust port 18 of the vacuum chuck groove 3.

The structure of the embodiment configured as above will be explained in more detail.

The connection between the pallet 2 and the contact cover 9 is sealed with a sealing member (O-ring) 8. This O-ring is for maintaining airtightness between the pallet and the contact cover 9, and it is not necessary to use an O-ring as long as it has this function. In addition, a contact cover 9 and a vacuum pipe 1 for the vacuum chuck are also included.
0 is hermetically connected by welding. Therefore, if an exhaust system is connected to the vacuum piping 10 for the vacuum chuck and the exhaust is performed,
The atmosphere in the vacuum chuck groove 3 can be exhausted through the contact cover 9, and the wafer 1 can be vacuum checked.

Voltage is applied to the electrostatic chuck electrode 4 through an upper contact 5 embedded in the back surface of the pallet 2, a lower contact 6 attached to the contact cover 9 via a contact presser spring 7, a power supply line 11, and a through terminal 13. is applied.

Next, the operation of the embodiment will be explained.

Vacuum piping 1 for vacuum chuck when the inside of the vacuum container is at atmospheric pressure
When the vacuum chuck exhaust system is connected to the vacuum chuck 0 and evacuated, the wafer 1 is attracted to the surface of the pallet 2. When the wafer 1 is attracted and a certain period of time has elapsed, the opening 1 inside the contact cover 9 opens.
6 and the degree of vacuum in the vacuum piping 10 for the vacuum chuck becomes higher than the degree of vacuum at which glow discharge is likely to occur. Thereafter, the voltage applied to the electrostatic chuck contact 5 is increased to a desired value. After raising it, the inside of the vacuum container begins to be evacuated.

As described above, the vacuum container can be evacuated while the electrostatic chuck is operating without causing glow discharge.

In addition, filler, which is the main cause of outgas, is not used, and the power supply # and Ill are the vacuum piping 10 for the vacuum chuck.
Since it is isolated from the vacuum container, the vacuum degree of the vacuum container will not decrease or contamination will occur.

Furthermore, using contacts 5 and 6 in the same manner as in the third section, pallet 2
Since the power supply cotton 11 is supplied with power, it is easy to attach and detach the power supply cotton 11.

[Effects of the Invention] According to the present invention, it is possible to make a vacuum/electrostatic chuck function without causing glow discharge.

Moreover, the degree of vacuum of the vacuum container is not lowered, and the inside of the vacuum container is not contaminated.

Moreover, the power supply line can be easily attached and detached.

Therefore, the present invention can be applied to, for example, semiconductor manufacturing equipment such as electron beam drawing snowmaking, and contributes to improved accuracy and simplification of the mechanism.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment. FIG. 2 is a configuration diagram of a pallet according to related technology. FIG. 3 is a configuration diagram of a pallet related to another related technology. (Explanation of symbols) 1...Wafer, 2...Pallet, 3...Groove for vacuum chuck, 4...Electrode for electrostatic chuck, 5...Upper contact, 6...Lower contact , 7... Biasing means (contact pressing spring), 8... Seal member (0 ring), 9...
Contact cover (insulator), 10... Vacuum piping for vacuum chuck, 11... Power supply line (welded coated W wire), 12... Vacuum container wall, 13... Penetration terminal, 14... Pallet Frame, 15... Epoxy filler, 16... Opening,
17... Closed space, 18... Exhaust port. Figure 1 Figure 2

Claims (4)

[Claims] (1) a contact cover having an opening; a contact attached to the contact cover via a biasing means within the opening;
It has a power supply line electrically connected to the contact, and a vacuum pipe connected to the contact cover in communication with the opening, and the power supply line is disposed within the vacuum pipe. Vacuum joint with built-in discharge prevention contact. (2) A pallet incorporating a vacuum chuck and an electrostatic chuck, characterized in that it has an electrostatic chuck contact near the exhaust port of the vacuum chuck groove. (3) A method for supplying power to a vacuum chuck and a pallet containing an electrostatic chuck, characterized in that power is supplied for the electrostatic chuck after the area where glow discharge is likely to occur is brought to a higher degree of vacuum than the degree of vacuum at which glow discharge is likely to occur. . (4) a contact cover having an opening; a contact attached to the contact cover via a biasing means within the opening;
A vacuum with a built-in discharge prevention electrode, comprising a power supply line electrically connected to the contact, and a vacuum pipe connected to the contact cover in communication with the opening, and the power supply line is arranged inside the vacuum pipe. The joint is connected to a pallet that has an electrostatic chuck contact near the exhaust port of the vacuum chuck groove, and the electrostatic chuck is applied after at least the inside of the vacuum piping is brought to a high vacuum higher than the vacuum area where glow discharge is likely to occur. A pallet power supply method characterized by supplying power to.