KR20070017790A - Wafer transfer apparatus - Google Patents

Abstract

The present invention relates to a wafer transfer device, and more particularly, to a wafer transfer device used in a semiconductor ion implantation device.

A wafer transfer apparatus according to an embodiment of the present invention includes a hand portion for seating a wafer and at least one pad provided on an inner circumferential surface of the hand portion to clamp the wafer and used as a coordinate center point in the alignment of the hand portion. A robot arm, at least one imaging member for detecting an alignment state of the hand when the hand unit is loading or unloading a wafer from a wafer cassette, and determining the image data detected by the imaging member to display the alignment state of the hand And determining the alignment of the hands to control an interlock to the wafer transfer device.

The above-described wafer transfer apparatus can accurately detect whether the robot arm repeatedly transferring the sheet of wafers is aligned at the optimum position, ie, the home position, for mounting the wafers.

Wafer transfer system, ion implantation apparatus, wafer transfer apparatus, robot arm, vision system, CCD camera,

Description

Wafer Transfer Device {WAFER TRANSFER APPARATUS}

1 is a block diagram schematically illustrating a wafer transport apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view illustrating the wafer transfer apparatus of FIG. 1 in more detail.

Explanation of symbols on the main parts of the drawings

10: wafer stage 116, 117, 119: first to third shaft

100: wafer transfer apparatus 121: control unit

110: robot arm 122: pad portion

112: hand portion 124: imaging member

114: hand support 126: light member

116: finger portion 130: robot arm drive unit

The present invention relates to a wafer transfer device for transferring wafers in a semiconductor manufacturing process.

The ion implantation method in the semiconductor manufacturing process is a technique of forcibly injecting impurity atoms of high kinetic energy into the wafer surface by ionizing an impurity material to be doped and then accelerating it. The ion implantation, which is such a forced physical implantation method, is widely used as an impurity implantation method because it has little particle movement in the horizontal direction compared to the thermal diffusion method, and thus greatly benefits the unit cell density.

An ion implanter that plays this role includes an ion source head that generates an ion beam, a classifier that allows only an ion beam of the desired mass to pass through, and an accelerator that accelerates the energy enough to inject the selected ions from the classifier into the wafer to the desired depth. It is composed of a concentrator which prevents the ion beam from being spread by the repulsive force, a syringe for moving the direction of the ion beam up, down, left, and right to uniformly distribute the ion beam on the wafer, and an end station where the wafer is loaded.

In general, the wafer transfer device provided in the end station has a hand part in which a pad for clamping the wafer is installed, a hand support for supporting the hand part, and a driving part for operating the hand support part.

The wafer transfer device transfers the wafer between the load lock chamber and the wafer stage by the driving unit. The wafer stage is installed at an end station of the ion implantation apparatus to sequentially seat the plurality of wafers while rotating the ion implantation process.

The hand portion is manufactured to wrap the edge of the wafer. One side of the hand portion includes a finger portion for performing an operation of opening and closing a predetermined shaft at an angle with respect to an axis, and is open when the wafer is mounted after being mounted to mount the wafer.

The inside of the hand portion has a pad formed with a groove into which the edge of the wafer can be inserted. A plurality of pads are provided along the inner circumferential surface of the hand portion, and when the hand portion mounts the wafer, the pad is substantially mounted in the groove.

The wafer transfer device having the above configuration is provided on one side inside the end station, and loads the wafer from the cassette coming through the load lock chamber onto the wafer chuck of the wafer stage for performing an ion implantation process on the wafer and the cassette from the wafer chuck. Unload the wafer.

However, the conventional wafer transfer apparatus described above has the following problems. The wafer transfer device transfers wafers between the wafer stage and the cassette while operating in a predetermined path by the drive unit. At this time, the robot arm may be twisted or shaken according to the repeated wafer transfer operation. Therefore, the wafer transfer apparatus is positioned at the optimum position for mounting the wafer, that is, at the home position, before the wafer transfer apparatus loads the wafer. Detect if

In the prior art, this is detected by a sensing unit including a predetermined light emitting and receiving sensor, but the sensing of the home position using the sensing unit does not accurately detect the home position. Thus, when the wafer transfer device is approached for mounting the wafer or when the wafer seated on the cassette is transferred to the wafer stage, the wafer may be dropped and broken, or the slot and wafer of the cassette may be scratched and damaged. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is a wafer capable of precisely checking whether the wafer transfer device is aligned on an optimum position, that is, a home position, for loading and unloading a wafer. In providing a transfer device.

Another object of the present invention is to provide a wafer transfer device that prevents scratching and breaking of wafers when the robot arm mounts and transfers wafers.

A wafer transfer apparatus according to an embodiment of the present invention for achieving the above object is provided on the hand portion for mounting the wafer and the inner peripheral surface of the hand portion to clamp the wafer, and is used as a coordinate center point in the alignment of the hand portion. A robot arm including at least one pad, at least one imaging member for detecting an alignment state of the hand when the hand portion loads or unloads a wafer from a wafer cassette, and image data sensed by the imaging member And a vision system for displaying an alignment state of the hands, determining whether the hands are aligned, and controlling an interlock or a predetermined control program in the wafer transfer device.

The imaging member is an optical camera that detects movement of the pad, and the optical camera is a CCD (Charge-Coupled Device) camera as an embodiment.

The imaging member detects an optimal position, ie, a home position, for the robot arm to load and unload a wafer, and the range of the home position is a coordinate system composed of X and Y axes on the vision system. The vision system serves as a criterion for determining the interlock of the wafer transfer device.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to FIGS. 1 and 2. The 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 fully explain the present invention to those skilled in the art, that is, those skilled in the art. Therefore, the shape of the elements in the drawings are exaggerated to emphasize a clearer description.

(Example)

1 is a schematic block diagram illustrating a wafer transfer apparatus according to an embodiment of the present invention. Referring to FIG. 1, a wafer transfer apparatus 100 according to an embodiment of the present invention includes a robot arm 110 and a vision system 120.

The robot arm 110 seats the wafer and moves to the required position in the process, and the vision system 120 can move the wafer without damage when the robot arm 110 loads or unloads the wafer. The robot arm 110 is controlled according to the home position range by detecting whether it is located within an optimum home position, that is, a home position (hereinafter, referred to as a "home position") range.

In order to perform the above-described functions, the vision system 120 may include a control member 121, a pad member 122, a camera member 124, and a light member ( 126, and a light source 128.

The pad portion 122 includes first and second pads 122a and 122b. The pad part 122 is used as a reference point for the optical camera 124 to photograph the alignment of the robot arm 110, and the imaging member 124 substantially photographs the position of the pad part 122. ) To detect alignment. To this end, the pad part 122 is installed in plurality on one side of the robot arm 110.

The imaging member 124 captures this by using the pad portion 122 of the robot arm 110 as a reference point. In one embodiment, the imaging member 124 may be a CCD (Charge-Coupled Device (CCD)) camera. The imaging member 124 includes first and second cameras 124a and 124b, and the first and second cameras 124a and 124b respectively allow the robot arm 110 to mount a wafer. When approaching the wafer, the motion of the first and second pads 122a and 122b is photographed at predetermined intervals to see if the first and second pads 122a and 122b meet the home position.

The light source 128 supplies a light source for the light member 126 to emit light, and the light member 126 is a pad unit (1) when the imaging member 124 continuously photographs at a predetermined time interval. Light is emitted toward 122, so that the imaging member 124 can be provided with sufficient light.

The controller 129 controls the robot arm 110, the imaging member 124, and the light source 128. In addition, the control unit 121 includes a display member (not shown) for displaying the image data captured by the camera member 124 so that an operator can recognize the control unit 121, and the control unit 121 reads the image data, thereby providing a robot. The operation of the arm 110 may be controlled by interlock setting, or the robot arm 110 may be temporarily suspended or the secondary home position may be detected. Here, the controller 121 controls the robot arm 110 because the robot arm 110 does not satisfy the home position may be variously applied.

The wafer transfer device 100 having the above-described configuration has a system that detects the home position of the robot arm 110 and reads it to control the operation of the robot arm 110.

Hereinafter, the wafer transfer apparatus 100 according to an exemplary embodiment of the present invention will be described in detail with reference to FIG. 2, which specifically implements the above-described wafer transfer apparatus 100.

Referring to FIG. 2, the wafer transport apparatus 100 is provided at one side of an end station of the ion implantation apparatus, and has a robot arm 110 and a vision system 120. The end station includes a process chamber (not shown) having a wafer stage 10 that rotates by mounting a plurality of wafers to perform an ion implantation process on a wafer W, the wafer stage 10 being It has a chuck 12 on which the single wafer W is seated and a wafer bracket 14 for detaching the wafer W from the chuck 12. The robot arm 110 is provided inside the process chamber to load a wafer while moving between a cassette (not shown) coming on the chuck 12 of the wafer stage 10 and a load lock chamber (not shown). And unloading.

The robot arm 110 is a hand member 112 for mounting a wafer, a hand support member 114 coupled to the hand part 112 to support the hand part 112, and a hand part. A finger member 116 rotated at a predetermined angle at the front end of the 112, and a driver member 130 for driving the robot arm 110.

The hand part 112 has a shape corresponding to the outer circumferential surface of the wafer W so as to surround the edge of the wafer W, and has an incomplete annular shape in which an end is not connected in order to access and mount the wafer W from the side. . On the inner circumferential surface of the hand portion 112, a pad portion 122 into which the wafer W is inserted is provided. The pad part 122 includes first to third pads 122a, 122b, and 122c, and a groove is formed so that the edge of the wafer W can be inserted therein. In the present embodiment, the second and third pad portions 122b and 122c are provided on the inner circumferential surface of the hand portion 112, and the first pad portion 122a is provided on the inner surface of the finger portion 116.

The hand support 114 has a bar shape. One end of the hand support part 114 is fixed by the hand part 112 and the second shaft 118 to support the hand part 112, and the other end of the hand support part 114 and the driving part 130 for operating the robot arm 110. 3 is fixed by the shaft 119.

It is coupled by the first shaft 117 at the end of the hand portion 112 of the finger portion 116. The finger portion 116 rotates a predetermined angle about the first shaft 117. That is, the finger portion 116 extends along the first shaft 117 as the axis when approaching the cassette (not shown) on which the wafer W is seated, and when the wafer W is mounted, the finger W is closed. )). In the present embodiment, the first pad 122a is installed on the inner circumferential surface of the finger portion 116 to mount the wafer W.

The first and second cameras 124a and 124b are fixed to one outside of the vacuum chamber and installed to photograph the first pad 122a and the second pad 122b, respectively. For example, the first and second cameras 124a and 124b may use the robot arm 110 provided inside the process chamber to pass the first and second pads (not shown) through a transparent window (not shown) outside the vacuum chamber. 122a, 122b). The first and second cameras 124a and 124b capture the movement of the first and second pads 122a and 122b at predetermined time intervals, respectively, and display the plurality of display members 121a, 121b and 121c of the controller 121. Mark on.

The movement of the first pad 124a captured by the first camera 124a is displayed on the first display member 121a, and the movement of the second pad 124b captured by the second camera 124b is second. It is displayed on the display member 121b.

The motions of the first and second pads 124a and 124b displayed on the first and second display members 121a and 121b are collectively displayed on the third display member 121c. The third display member 121c is set with a coordinate system composed of X and Y axes, and a home position range having a predetermined X and Y axis sections is set on the coordinate system.

The setting of the home position range is an arbitrary average value determined by the operator a plurality of times when the robot arm 110 is installed, and the operator collectively sets the home position range on the coordinate system.

Thus, on the third display member 121c, a coordinate system consisting of the X-axis and the Y-axis in which the home position range is set is set, and the first and second pads photographed by the first and second cameras 124a and 124b, respectively. The motions of 122a and 122b are combined and displayed on the coordinate system as one point.

If the point is taken within the home position range, the controller 121 determines that the alignment state of the robot arm 110 is normally positioned to continue the operation of the wafer transfer device 100, and the point is the home position. When the picture is taken out of the range, the controller 121 determines that the alignment state of the robot arm 110 is abnormally positioned to set an interlock for stopping the operation of the wafer transfer device 110.

The wafer transfer apparatus according to the embodiment of the present invention has been described in detail above. However, the present invention is not limited to the wafer transfer apparatus used for the semiconductor ion implantation apparatus described above. In particular, the above-described imaging member and the pad unit may be installed in various positions and methods so as to detect the alignment state of the robot arm, and the interlock setting method of the vision system may also be operated in various manners, for example, for a predetermined time. It can be implemented as a setting of various interlock methods such as stopping or attempting to mount the wafer again at a secondary or higher level. In addition, it will be apparent to those skilled in the art that the above-described wafer transfer apparatus according to the present invention may be applicable to all wafer transfer apparatuses used in semiconductor processes, not just the wafer transfer apparatus used in the ion implantation apparatus.

The wafer transfer apparatus according to the present invention described above can accurately detect whether the robot arm repeatedly transferring the sheet of wafers is aligned at an optimum position, that is, a home position, for mounting the wafers.

Thus, there is an effect of preventing scratches and breakage of the wafer, which occurs when the robot arm is mounted and transported in a state outside the home position region.

Claims (12)

In the wafer transfer apparatus, A robot arm comprising a hand portion and at least one pad provided on an inner circumferential surface of the hand portion to clamp the wafer and used as a coordinate center point in the alignment of the hand portion; At least one imaging member for sensing an alignment state of the hand portion when the hand portion loads or unloads a wafer from a wafer cassette; And a vision system for determining the image data sensed by the imaging member to display the alignment state of the hands, and determining whether the hands are aligned to control an interlock or a predetermined control program in the wafer transfer device. Wafer transfer apparatus. The method of claim 1, And the image pickup member is an optical camera that detects movement of the pad. The method of claim 2, The optical camera is a wafer transfer device, characterized in that the CD (Charge-Coupled Device) camera. The method of claim 2, The wafer transfer device further comprises a light member for providing sufficient light to the optical camera when the optical camera is photographed. The method of claim 2 or 3, The wafer transfer device is a wafer transfer device, characterized in that provided in the end station of the semiconductor ion implantation device. In the wafer transfer apparatus, A robot arm including a hand portion on which a wafer is mounted; And a plurality of image pickup members for detecting whether the robot arm is positioned at a position for mounting a wafer, that is, within a home position range. The method of claim 6, And at least one pad on the outer circumferential surface of the hand part, the imaging member being a reference point for detecting the alignment of the robot arm. The method of claim 6, And the wafer transfer device further comprises a light member for providing sufficient light to the imaging member when the imaging member is photographed. The method of claim 7, wherein The pad is provided with a plurality on the inner surface of the hand portion, the groove is inserted into the wafer transfer device, characterized in that for mounting the wafer. The method according to claim 6 or 9, The wafer transfer apparatus further comprises a vision system for displaying image data recognized by the imaging member, and reading the image data to control an interlock or a predetermined control program of the wafer transfer apparatus. Device. The method of claim 10, The home position range is represented by a coordinate system consisting of X and Y axes on the vision system, wherein the coordinate system is a reference for the vision system to determine the interlock of the wafer transfer device. The method according to any one of claims 6 to 9, The wafer transfer device is a wafer transfer device, characterized in that provided in the end station of the semiconductor ion implantation device.

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