KR200267583Y1 - Apparatus for sensing a home position of load lock chamber - Google Patents

Abstract

The present invention relates to a home position sensing device for a load lock chamber, and more particularly, to a home position sensing device for a load lock chamber which is provided with a light source having a constant wavelength, which is provided so as to face each other with a lead screw (34) interposed therebetween, A light receiving element 120 for receiving light output from the light emitting element 110 and outputting a home position sensing signal; And an optical through hole 130 formed through the lead screw 34 such that light output from the light emitting element 110 passes through the wafer cassette 1 when the wafer cassette 1 reaches the home position and is received by the light receiving element 120 And the position of the wafer cassette in the load lock chamber can be accurately controlled by accurately detecting the groove position of the wafer cassette irrespective of the vibration or impact generated when the wafer cassette is moved. So that the related parts and the wafer are prevented from being damaged.

Description

Field of the Invention [0001] The present invention relates to a home position sensor for a load lock chamber,

The present invention relates to a home position sensing apparatus for a load lock chamber, and more particularly, to a home position sensing apparatus for a load lock chamber that is simple in structure and accurately detects a groove position of a wafer cassette regardless of vibration or shock generated when the wafer cassette moves And a home position sensing device.

Generally, in order to perform a manufacturing process of a semiconductor device, a load having a condition close to a process condition such that a rapid change does not occur in the wafer due to an environment inside the process chamber such as a high vacuum, before loading the wafer into the process chamber, Mount the wafer in the lock chamber.

In order to load / unload wafers in the load lock chamber, a wafer cassette loaded with a certain number of wafers is usually loaded / unloaded by the cassette transfer arm into the load lock chamber, and the wafer cassette is left in the load lock chamber Only the wafer is loaded / unloaded into the process chamber by the wafer transfer arm.

A load lock chamber used in a manufacturing process of a semiconductor device will now be described with reference to the accompanying drawings.

FIG. 1 is a side sectional view showing a load lock chamber according to a conventional technique, and FIG. 2 is a sectional view taken along line A-A 'of FIG. As shown in the figure, the load lock chamber 10 is provided with a door 20 rotatably installed forward and backward to allow the wafer cassette 1 to move in and out, and a wafer cassette 1 mounted on the lower side in a vertical direction An elevator 30 for reciprocating is provided.

The elevator 30 includes a lifting plate 31 positioned on the inner side of the load lock chamber 10 and on which the wafer cassette 1 is seated, a sliding plate 30 slidably coupled through the bottom surface of the load lock chamber 10 vertically, An elevating shaft 32 coupled to the bottom surface of the elevating plate 31 and an elevating member 33 fixedly coupled to the elevating shaft 32 at one side and a lead screw 32 screwed to the other side of the elevating member 33 A guide member 35 slidably coupled to the lead screw 34 and coupled to the lower side of the elevating member 33, a motor 37 connected to the lead screw 34 by a belt 36, And a control unit 38 for controlling the motor 37. [

When the wafers are loaded one by one from the wafer cassette 1 placed on the lifting plate 31 of the load lock chamber 10 by a wafer transfer arm (not shown) or unloaded to the process chamber (not shown), the control unit 38 drive the motor 37 to move the lifting plate 31 on which the wafer cassette 1 is mounted up and down at regular intervals.

That is, the control unit 38 drives the motor 37 to rotate the lead screw 34 by the belt 36 and the elevation member 33 moves in the vertical direction by the rotation of the lead screw 34, The lifting plate 31 moves upward and downward together with the lifting shaft 32 as the lifting member 33 moves.

Meanwhile, the guide member 35 guides the elevating member 33 by sliding the elevating member 33 along the lead screw 34 when moving the elevating member 33 in the vertical direction.

The control unit 38 has to set a reference position for controlling the position of the wafer cassette 1 and performs control on the required ascending / descending distance from the reference position.

Therefore, the load lock chamber 10 is provided with the sensing unit 40 that senses the groove position to be the reference position of the wafer cassette 1.

The sensing unit 40 includes a mounting member 41 which is coupled to the side of the lifting member 33 and has a mounting groove 41a having a " A light receiving element 43 for receiving light output from the light emitting element 42 and for outputting a home position sensing signal, a light emitting element 42 for emitting light having a predetermined wavelength, And a wafer cassette 1 which is formed so as to protrude laterally at a predetermined portion of the vertical axis 44 and which is seated on the lifting plate 31, And a sensing piece 45 positioned between the light emitting element 42 and the light receiving element 43 when reaching the home position.

Therefore, when the sensing piece 45 is positioned between the light emitting element 42 and the light receiving element 43 when the elevation member 33 is moved in the vertical direction by the rotation of the motor 37, The control unit 38 for receiving the signal performs an initializing operation, and the home position at this time is the reference position for the control of the movement of the wafer cassette 1 after the control unit 38 is initialized.

The conventional load lock chamber 10 has a problem in that the mounting member 41 and the sensing piece 45 of the sensing unit 40 protrude to the outside to increase the volume of the device and complicate the structure .

The position of the light emitting element 42 and the light receiving element 43 or the detecting piece 45 is changed by vibration or external impact of the lifting shaft 32 and the elevating member 33, In addition, the power supply lines and the sense signal lines connected to the light emitting device 42 and the light receiving device 43 protruding from the outside collide with each other even when they collide with each other.

Due to these problems, the home position sensing means 40 can not perform the function, so that the wafer cassette 1 collides with the inner surface of the load lock chamber 10 and the expensive related parts are broken, and the wafer cassette 1 Does not reach the predetermined position, the wafer transfer arm will collide with the wafer when handling the wafer and cause serious damage to the wafer.

It is an object of the present invention to provide an apparatus and a method for detecting a position of a wafer cassette by accurately detecting a groove position of a wafer cassette regardless of vibration or shock generated when the wafer cassette is moved, The present invention is to provide a home position sensing apparatus for a load lock chamber that performs control properly and prevents positional control of the wafer cassette from being performed, thereby preventing the associated parts or the wafer from being damaged.

In order to achieve the above object, the present invention provides a light emitting device having a light emitting element for outputting light having a predetermined wavelength, the light emitting element being provided so as to face each other with a lead screw interposed therebetween, A light receiving element for outputting a home position sensing signal in addition to the reception box; And an optical through hole formed through the lead screw such that light emitted from the light emitting element passes through the wafer cassette when the wafer cassette reaches the home position and is received by the light receiving element.

The light emitting element and the light receiving element are provided on both sides of the mounting groove formed inside the elevating member so as to be perpendicular to the lead screw.

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1 is a side sectional view showing a load lock chamber according to a conventional technique,

2 is a sectional view taken along the line A-A 'in Fig. 1,

3 is a side cross-sectional view of the apparatus for detecting a home position of a load lock chamber according to the present invention,

4 is a cross-sectional view taken along the line B-B 'in Fig.

Description of the Related Art

110; A light emitting device 120; Receiving element

130; An optical through hole 140; Mounting groove

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

FIG. 3 is a side sectional view showing the apparatus for detecting the home position of the load lock chamber according to the present invention, and FIG. 4 is a sectional view taken along line B-B 'of FIG. As shown in the figure, the home position sensing apparatus 100 for sensing the home position of the wafer cassette 1 mounted inside the load lock chamber 10 is provided with a lead screw 34 at a portion of the lift member 33, The light emitting element 110 and the light receiving element 120 provided to face each other with the screw 34 interposed therebetween and the light output from the light emitting element 110 when the wafer cassette 1 reaches the groove position And an optical through hole (130) formed through the lead screw (34).

The light emitting device 110 outputs light having a predetermined wavelength and the light receiving device 120 receives light output from the light emitting device 110 and outputs a home position sensing signal to the control unit 38. The light emitting device 110 and the light receiving device 120 are preferably a light emitting diode and a photodiode, respectively.

3, it is preferable that the light emitting element 110 and the light receiving element 120 are provided on both sides of the mounting groove 140 formed inside the elevating member 33 so as to be perpendicular to the lead screw 34 Do. That is, the mounting groove 140 is formed on the inner side of the elevating member 33 and in a horizontal direction with respect to the screw hole to which the lead screw 34 is screwed, and on both sides of the mounting groove 140, (110) and the light receiving element (120) face each other.

Therefore, since the light emitting element 110 and the light receiving element 120 are provided inside the elevating member 33, the interference between the elevating member 33 and the elevating member 33 The inner side of the light emitting element 110 and the light receiving element 120 and the optical through hole 130 are minimized in position by the vibration of the lifting plate 31 and the lifting shaft 32. Therefore, Can be detected.

The optical through hole 130 is formed in the horizontal direction so that the light output from the light emitting element 110 passes through the light receiving element 120 when the wafer cassette 1 is positioned at the home position, .

The operation of the home position sensing apparatus of the load lock chamber having such a structure is as follows.

When the motor 37 is driven, the lead screw 34 is rotated by the belt 36 and the elevation member 33 is moved in the vertical direction by the rotation of the lead screw 34, The lifting plate 31 connected to the shaft 32 moves together in the vertical direction.

When the lifting plate 31 is moved in the vertical direction, when the wafer cassette 1 positioned on the upper surface thereof reaches the home position, light output from the light emitting device 110 provided on the lifting member 33 is guided to the light Passes through the passing groove (130) and is received by the light receiving element (120). At this time, the control unit 38 receives the home position sensing signal output from the light receiving element 120, detects that the wafer cassette 1 has reached the home position, stops the motor 37, The controller controls the motor 37 such that the wafer cassette 1 is moved up and down to a predetermined position with the home position of the wafer cassette 1 as a reference position.

As described above, according to the preferred embodiment of the present invention, the structure is simple and accurately detects the groove position of the wafer cassette irrespective of the vibration or shock generated when the wafer cassette is moved.

As described above, the apparatus for detecting the home position of the load lock chamber according to the present invention has a simple structure and accurately detects the groove position of the wafer cassette irrespective of the vibration or shock generated when the wafer cassette moves, The position control of the cassette is properly performed, and the position control of the wafer cassette is correctly performed, thereby preventing the related parts and the wafer from being damaged.

The above description is only one embodiment for implementing the home position sensing apparatus of the load lock chamber according to the present invention. The present invention is not limited to the above-described embodiment, It will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.

Claims (2)

A lift plate positioned inside the load lock chamber to raise and lower the wafer cassettes located at the inside of the load lock chamber at a predetermined interval; an elevating shaft coupled to the lift plate through the bottom surface of the load lock chamber vertically; A load lock chamber including an elevating member having one side fixedly coupled to the elevating shaft and an elevator including a lead screw screwed to the other side of the elevating member and rotated by a motor, A light emitting element that emits light having a predetermined wavelength and is installed to face each other with the lead screw interposed therebetween at a coupling portion of the elevating member with the lead screw and a light receiving element that receives light output from the light emitting element, A light receiving element for outputting the light; And An optical through hole formed through the lead screw so that light emitted from the light emitting element passes through the wafer cassette when the wafer cassette reaches a home position and is received by the light receiving element; And a controller for detecting the home position of the load lock chamber. The apparatus according to claim 1, wherein the light emitting element and the light receiving element are provided on both sides of a mounting groove formed inside the elevating member so as to be perpendicular to the lead screw.