KR20040069451A - Wafer buffer stage - Google Patents

Abstract

PURPOSE: A wafer buffer stage is provided to prevent previously a process error by loading correctly a wafer on the center of a plate by a position control unit. CONSTITUTION: A wafer is loaded on an upper surface of a plate(110). A plurality of guide pins(120) are installed at the plate. The guide pins are used for supporting the wafer loaded on the upper surface of the plate. A position control unit(130) is used for controlling a position of the wafer in order to load correctly the wafer on the guide pins. The position control unit includes a motor(132), a lead screw(136) rotated by the motor, and a moving block(138) having a screw member. The moving block is moved in a straight line when the lead screw is rotated by the motor.

Description

Wafer buffer stage {WAFER BUFFER STAGE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer buffer stage in which a baking process is performed, and more particularly, to a wafer buffer stage capable of calibrating a wafer that is abnormally loaded in a facility for semiconductor production.

Many types of equipment are used to produce semiconductors. These facilities have a number of chambers (process chamber, load lock chamber, etc.) to facilitate a smooth process. A buffer stage for relaying (turning over) the wafer exists between the process chamber and the load lock chamber.

The wafer is transferred from the load lock chamber to the chuck of the process chamber through the buffer stage. When the wafer is transferred while the wafer is misaligned, a wafer broken or a transfer error is caused.

As shown in FIG. 5, the loading position of the wafer w is changed in the chuck 12 of the process chamber 10 due to various causes (pressure change or mechanical error or error in position setting by an engineer). Doing. In the drawing, the wafer at the abnormal position is indicated by a dotted line. For example, when the transfer robot transfers the wafer from the chuck to the buffer stage 20 while the loading position of the wafer w is slightly misaligned, a portion of the wafer w is placed on the wafer guide 22 as shown in FIG. 6. A problem arises. This loading failure (incorrect loading) causes wafer brocken and process errors.

SUMMARY OF THE INVENTION The present invention has been made to solve this conventional problem, and an object thereof is to provide a new type of wafer buffer stage that can be positioned so that the wafer is aligned with the center of the stage even if the wafer is loaded incorrectly.

1 is a partially exploded perspective view showing a wafer buffer stage in accordance with an embodiment of the present invention;

2 is a plan view of a wafer buffer stage in accordance with an embodiment of the present invention;

3 is a cross-sectional view taken along the line A-A shown in FIG.

4A and 4B are diagrams showing position correction of a wafer in a wafer buffer stage.

FIG. 5 shows a wafer loaded with the loading position misaligned in the chuck of the process chamber; FIG.

FIG. 6 is a view illustrating a state in which a portion of a wafer is placed on a wafer guide in an existing wafer buffer stage.

Explanation of symbols on the main parts of the drawings

110: plate

120: guide pin

130: position adjusting means

132: motor

136: road screw

138: moving block

According to a feature of the present invention for achieving the above object, the wafer buffer stage includes a plate on which the wafer is loaded; Guide pins installed on the plate and supporting the wafer loaded on the plate in at least three portions; And means for adjusting the position of the wafer such that the wafer placed on the guide pins is in a normal position.

According to an embodiment of the invention, the wafer positioning means includes a motor; A lead screw rotating under the driving force of the motor; And a moving block having a screw member which moves linearly back and forth according to the rotation of the lead screw and to which the guide pin is mounted.

For example, embodiments of the present invention may be modified in various forms, and the scope of the present invention should not be construed as being limited by the embodiments described below. This embodiment is provided to more completely explain the present invention to those skilled in the art. Accordingly, the shape of the elements in the drawings and the like are exaggerated to emphasize a clearer description.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to FIGS. 1 to 4B. In addition, in the drawings, the same reference numerals are denoted together for components that perform the same function.

1 to 3, the wafer buffer stage 100 according to the present invention includes a plate 110, guide pins 120 on which a wafer w transferred from a transport robot (not shown) is placed, and a wafer. It has a position adjusting means 130.

The guide pins 120 are installed at four places of the plate 110. The guide pin 120 is moved back and forth by the wafer position adjusting means 130.

The wafer position adjusting means 130 adjusts the position of the wafer by moving the guide pins 120 so that the wafer supported by the guide pins 120 is positioned at a normal position.

In more detail, the wafer position adjusting means 130 is composed of a motor 132, a lead screw 134, a belt 136 and a moving block 138. The lead screw 134 is rotated by the driving force of the motor 132 through the belt 136. The moving block 138 has a screw member 139 that is screwed to the lead screw 134, the moving block 138 is mounted with the guide pin 120.

The moving block 138 is moved by the screw member 139 is moved back and forth linearly according to the rotation of the lead screw 134. The moving block 138 is linearly moved under the guidance of the guide groove 112 formed in the plate 110. On the other hand, the plate 110 is provided with a stopper 114 for limiting the movement of the guide pin 120.

The structural feature of the present invention is that the wafer placed on the guide pins 120 has a means for adjusting its position so that it can be placed at the center of the plate 110. This structural feature is the loading position miss, when the wafer is placed on the guide pins 120, the loading position of the wafer is rearranged by the positioning means 130.

4A and 4B are diagrams illustrating a wafer position correction process in a wafer buffer stage.

As shown in FIG. 4A, when the wafer w is placed on the guide pins 120, the lead screw 134 is rotated by driving the motor 132 of the position adjusting means 130. The moving block 138 goes straight along the guide groove 112 in the center direction (inside) of the plate 110 by the rotation of the lead screw 134, the guide pin 120 is the moving block While moving with 138, the position of the wafer w is moved to the home position.

Before the wafer is loaded onto the wafer buffer stage 100, the guide pins 120 are positioned slightly wider than the size of the wafer w. When the wafer is placed on the guide pins 120, the guide pins are placed. 120 is moved forward by the position adjusting means 130 to move to the most suitable position. The movement of the guide pin 120 is controlled by controlling the driving of the motor using a stopper 114 mounted on the upper surface of the plate 1100 or a separate sensor. When the wafer is aligned in the positive position, the motor Rotate to move the guide pins to the outer initial position.

According to the present invention, even if a misalignment of the wafer occurs in the previous process, since the wafer is rearranged in the wafer buffer stage, it is possible to prevent problems such as wafer brokin that may occur in the subsequent process.

In the above, the configuration and operation of the wafer buffer stage according to the present invention have been shown according to the above description and drawings, but this is merely an example, and various changes and modifications can be made without departing from the spirit of the present invention. Of course.

According to the wafer buffer stage of the present invention, even if the wafer is incorrectly loaded on the guide pins of the plate, the position of the wafer is adjusted so that the wafer can be placed in the center of the plate by the positioning means. Therefore, process defects that may occur in subsequent processes can be prevented in advance.

Claims (4)

In the wafer buffer stage: A plate into which the wafer is loaded; Guide pins installed on the plate and supporting the wafer loaded on the plate in at least three portions; And means for adjusting the position of the wafer such that the wafer placed on the guide pins is in a normal position. The method of claim 1, The wafer positioning means A motor; A lead screw rotating under the driving force of the motor; Wafer buffer stage, characterized in that it comprises a moving block having a screw member for linearly moving back and forth in accordance with the rotation of the lead screw and the guide pin is mounted. The method of claim 2, And a belt for transmitting power of the motor to the lead screw. The method of claim 2, The wafer position adjusting means The wafer buffer stage further comprises a stopper for limiting the movement of the moving block.