JPS61105854A - Wafer chuck - Google Patents

Abstract

PURPOSE:To make it feasible to pick up a wafer out of chuck by a method wherein lever members with ends movable along through holes from the recessed positions to the protruded positions beyond surface of base are provided. CONSTITUTION:Three through holes 5 are opened on the positions meeting a base member 4 with a plane 3 mounting a wafer 2 of chuck 1 at the central angle of 120 degrees to provide three lever members 7 pivoting upon fulcrums 6 as middle points on the backside. The lever members 7 with ends 8 abutting against the wafer 2l and the other ends 9 abutting against lever depressing parts are normally situated in the positions recessed from the upper surface 3 of base member 4 to be protruded beyond the upper surface 3 by the lever members 7 pivoting upon the fulcrums 6 as middle points with the ends 9 depressed. Resultantly the wafer 2 may be easily picked up out of the chuck 1. Besides, even temperature control and chuck insulation may be attained since the driving source of wafer life is externally provided and the upper surface 3 is formed into evenly flat sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wafer chuck used for holding a wafer in semiconductor manufacturing equipment.

Exposure and resist coating in various semiconductor manufacturing equipment such as aligners, coaters, and probers.

The wafer is held by a chuck for operations such as probing, and after the various operations described above are completed, the wafer is removed from the chuck.

Therefore, it is desirable that the chuck not only have the function of simply adsorbing the wafer, but also have a mechanism that facilitates ejecting the wafer. Three types of chucks are conventionally known, including a Bernoulli type, an air unloading type, and a wafer lift type, as chucks equipped with a mechanism for facilitating the unloading of wafers.

The Bernoulli chuck has a structure in which the wafer is levitated by flowing air over the surface of the wafer to create a negative pressure. In this case, since a large amount of air is blown onto the surface of the wafer, there is a risk that dust will adhere to it, which is not preferable.

Next, in the case of the air carry-out method, the wafer is similarly levitated by air, and then air is blown onto the levitated wafer from a separately provided air release device to remove the wafer from the chuck. In this case, the position of the wafer becomes unstable, and the wafer must be positioned again before being returned to the wafer cassette.

Finally, in the wafer lift type chuck, the wafer is lifted from the chuck by the lift i, and a hand is inserted into the back surface of the wafer to carry out the wafer. In this case, it is necessary to provide a lift mechanism inside the wafer chuck, which complicates the structure inside the chuck. Furthermore, the lift mechanism becomes an obstacle when it is necessary to electrically insulate the chuck from the outside. Furthermore, if it is necessary to control the temperature of the chuck, the lift mechanism makes uniform temperature control difficult.

SUMMARY OF THE INVENTION An object of the present invention is to provide a wafer chuck that does not have the above-mentioned drawbacks and has a simple mechanism for facilitating wafer unloading. The wafer chuck of the present invention is an improved version of the conventional wafer lift type chuck, and can easily carry out the wafer from the chuck by simply having a wafer lift mechanism with a simple lever structure.

Preferred embodiments of the invention will now be described with reference to the accompanying drawings. FIGS. 1 and 2 each illustrate a wafer chuck l constructed in accordance with a preferred embodiment of the present invention.
FIG. The chuck 1 is composed of a base member 4 having a surface 3 on which a wafer 2 is placed, and three through holes 5 are formed in the base member 4 at positions having a central angle of 120 degrees.

Three lever members 7 that rotate about a fulcrum 6 are installed on the back side of the base member 4. The lever member 7 has an end 8 that comes into contact with the wafer 2 placed on the base L, and an end 9 that comes into contact with a lever pressing part of a wafer hand (not shown). The end portion 8 is normally located at a recessed position from the − face 3 of the base 4, but it is
When the end portion 9 is pushed down by the lever member 7 (not shown), the lever member 7 rotates about the fulcrum 6, so that it protrudes from the upper surface 3 of the base 4. Therefore, a space is formed between the wafer 2 and the upper surface 3 of the base member 4, making it easier to carry out the wafer 2 from the chuck l.

FIG. 3 is a plan view of a wafer chuck constructed in accordance with another embodiment of the invention. Like the chuck shown in FIG.
Three through holes 5 are formed at diagonal positions.

The lever members 7 in FIG. 1 extend radially so that the central angle forms 120 degrees, but in FIG. is longer than that of the central lever member 7. Further, the shapes of the lever members on both sides are bent.

Also in the case of FIG. 3, the lever member 7 has an end 8 that comes into contact with the wafer 2 placed on the base I-, and an end 9 that comes into contact with the lever pressing part of the wafer hand (not shown). There is. The end portion 8 is normally in a retracted position from the second surface 3 of the base, but when the end portion 9 is pushed down by a lever depressing portion (not shown) of the hand, the lever member 7 rotates around the fulcrum 6. Therefore, it protrudes from the -1- plane 3 of the base. Therefore, a space is formed between the wafer 2 and the second surface 3 of the base member, making it easier to carry out the wafer 2 from the chuck l.

As explained above, the present invention solves the problem of chuck insulation, which was difficult with conventional wafer lift type chucks, by providing the driving source for the wafer lift outside the chuck, and also makes the upper surface of the chuck uniform and flat. Since it can be configured with a face plate, uniform temperature control can be easily achieved.

[Brief explanation of the drawing]

1 and 2 are a plan view and a cross-sectional view, respectively, of a wafer chuck constructed in accordance with a first embodiment of the present invention. FIG. 3 is a plan view of a wafer chuck constructed in accordance with a second embodiment of the present invention. 1---Chuck 2---Wafer 3---One side
4---Base 5---One hole
6---Fulcrum 7-11 Lever

Claims (1)

[Claims] 1. A base configured to place a wafer; a through hole formed in the base; and a position protruding from the upper surface of the base through the through hole;
A wafer chuck comprising: a lever member having an end portion that is movable between a position retracted from the upper surface of the base and a position retracted from the upper surface of the base. 2. The wafer chuck according to claim 1, wherein three through holes and three lever members are provided. 3. The wafer chuck according to claim 2, wherein the through hole is located on a line that equally divides the base into three parts.