KR20120131105A

KR20120131105A - Broken wafer recovery system

Info

Publication number: KR20120131105A
Application number: KR1020120053723A
Authority: KR
Inventors: 크래이그 라일 스티븐스; 데이비드 에릭 버크스트레서; 웬델 토마스 블로니간
Original assignee: 오보텍 엘티 솔라 엘엘씨
Priority date: 2011-05-24
Filing date: 2012-05-21
Publication date: 2012-12-04

Abstract

The present invention relates to apparatus and methods useful for manufacturing systems for repairing and cleaning damaged wafers, in particular using silicon wafers carried on trays. Removal of damaged wafers and pieces from within the manufacturing system is possible without disassembling the system and without the need for manual work.

Description

Damaged Wafer Recovery System {BROKEN WAFER RECOVERY SYSTEM}

The present invention relates to systems and methods for processing substrates such as silicon wafers for semiconductors, solar cells, and other applications in clean environments. More specifically, the present invention relates to systems and methods for treating damaged substrates, particularly damaged silicon wafers.

State-of-the-art systems for manufacturing semiconductor wafers generally use a mainframe, which is equipped with several processing chambers. Other systems, especially those used for solar cell manufacturing, are structured as in-line systems, where the substrate transfer from one chamber to the next is performed linearly. Regardless of the architecture used, at some point the wafer is moved from an atmospheric environment to a vacuum environment. This is done to introduce the wafer into a vacuum processing chamber such as chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), physical vapor deposition (PVD) systems, and the like.

In many systems used to fabricate integrated circuits, wafers move individually from chamber to chamber. On the other hand, many linear systems use trays for solar cell manufacturing, where multiple silicon wafers are located. The trays may move linearly from chamber to chamber, or the wafers may be separated and moved and placed on stationary trays, so that in each chamber many silicon wafers are processed simultaneously on a single tray. For example, 64 boards of 125 mm x 125 mm each.

As can be appreciated, such a system operates under strict processing rules in a clean room. However, sometimes the wafer is damaged during processing or transfer within the system. Such damage creates broken pieces, chips and dust that cause contamination and disrupt production. In general, when such damage occurs, the system must be stopped and separated for manual cleaning. Such confusion is wasteful in terms of production and also requires manual labor for cleaning. The effect on system throughput is generally very sensitive in solar cell fabrication, where the throughput of each system is on the order of 1-3 thousand wafers per hour.

The problem to be solved by the present invention is to provide a damaged wafer recovery system.

The following summary of the invention is included to provide a basic understanding of some aspects or features of the invention. Since this summary is not an in-depth overview of the invention, it is not intended to specifically identify the points or essential elements of the invention and is not intended to describe the scope of the invention. Its purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description that is presented below.

Various embodiments of the present invention provide systems and methods for detecting, repairing and cleaning damaged wafers. Embodiments of the present invention are particularly useful for fabrication systems using silicon wafers that are carried on a tray. According to embodiments of the present invention, removal of damaged wafers and pieces from within the manufacturing system is possible without disassembling the system and without the need for manual work.

According to various embodiments of the present invention, there is provided a system capable of removing a damaged substrate for use in a substrate processing system, comprising: a suction head having an inlet; A placement mechanism to move the suction head to the location of the damaged substrate; Suction pump; A flexible tube connecting said suction head to said suction pump. A hood is disposed at the inlet of the suction head and a setback extension is provided below the hood to allow air flow to the inlet and to prevent heat conduction from the tray to the hood. A plurality of movable pins are extendable around the inlet of the suction head to break the substrate into smaller pieces for easy removal. The head placement mechanism may be comprised of a first gantry that provides linear motion in one direction and a second gantry that provides linear motion in a perpendicular direction. Alternatively, the head placement mechanism may consist of a rotatable pivot that provides rotational motion and an arm that provides linear motion. The storage and disposal station stores the suction head when not in use and discards any remaining scrap removed by the suction head. An optical sensor, such as a digital camera, is connected to the controller to monitor and / or control the placement mechanism that detects the damaged substrate and moves the suction head over the location of the damaged substrate, and to verify that the damaged wafer was successfully removed in a previous process. do.

Embodiments of the present invention disclose a method of removing a piece of a broken wafer from a plate supporting a plurality of wafers in a manufacturing system, the method comprising: analyzing an optical signal to determine if one of the plurality of wafers is broken; If it is determined that the broken wafer is in position on the plate, transferring the plate to the exchange station, placing the suction head over the broken wafer position, and operating the suction pump to remove the broken wafer piece. Optionally, when it is determined that the broken wafer is positioned on the plate, the plate is moved to the position of the second optical sensor to see if the broken wafer is on the plate. In another embodiment, the incoming wafer is analyzed to determine if there is a wafer crack or damage prior to processing. To minimize the possibility of wafer damage in the processing apparatus, the suspected wafer is removed from the incoming tray.

Other aspects and features of the invention will be apparent from the various embodiments described herein, which are within the scope and spirit of the invention as claimed in the claims.

According to the present invention, a damaged wafer recovery system can be provided.

1A and 1B are general schematic diagrams depicting the major components of examples of system architecture for implementing embodiments of the present invention.
2A and 2B are general schematic diagrams depicting major components of a system architecture in accordance with embodiments of the present invention, showing a damaged substrate repair system installed over the factory interface of the system shown in FIGS. 1A and 1B.
FIG. 2C shows another embodiment showing a flipping station having two processing chambers arranged linearly and a damaged wafer recovery system located between the two processing chambers.
3A is a general schematic diagram depicting major components of a damaged wafer repair system in accordance with one embodiment of the present invention.
3B is a general schematic diagram depicting the major components of a damaged wafer repair system according to another embodiment of the present invention.
4 is a general schematic diagram depicting additional elements of the damaged wafer recovery system shown in FIGS. 3A and 3B.
5 shows a susceptor that can be used to process a substrate in a plasma processing chamber.
The invention is described herein with respect to the specific embodiments illustrated in the drawings. However, it is to be understood that the various embodiments depicted in the drawings are merely exemplary and do not limit the invention as defined by the claims.

Various embodiments of the present invention provide an apparatus and method for repairing damaged wafer pieces, for example, during fabrication of semiconductor integrated circuits, solar cells, flat panel displays, LEDs, and the like. Embodiments of the present invention are particularly useful in systems that use a tray to transport and / or process a wafer.

1A shows an example of a processing system that can be used to implement an embodiment of the present invention. It is to be understood that other architectures or other systems may be used to implement the invention, and the system shown in FIG. 1A is provided by way of example only. For simplicity of explanation, only a single processing chamber 100 is shown disposed at one end of a simple linear system. In this embodiment, the processing chamber is, for example, a plasma processing chamber such as a PECVD or PVD processing chamber. One vacuum valve 102 is provided on the side of the chamber 100 to introduce the tray 104 into the chamber 100. A loadlock chamber 110 is provided at the side of the chamber 100, and a vacuum valve 112 is provided at the inlet of the load lock 110. A loading chamber 120, also referred to as a factory interface, is provided on the inlet side of the load lock chamber 110 and is used to load tray 104 for processing and to unload the processed wafer from the system.

The flow of wafers shown in FIG. 1A is described in more detail from the wafer loaded on the right side of the system. The tray 104 with the substrate is loaded into the loading chamber 120. In particular, the tray may be held in the system and the wafer loaded on a tray in the system, or the tray may be loaded outside the system and brought and loaded onto the loading chamber 120. The tray 104 may carry 64 substrates arranged in a two-dimensional array, for example. The tray is then introduced into the load lock 110, the gate valves 102 and 112 are closed and the vacuum pump is operated such that the load lock 110 is in vacuum level matching or close enough to that of the chamber 100. The valve 102 is then opened and the tray is moved into the chamber for processing. That is, the wafer is held on the tray 104 while being processed in the chamber 100. After the processing is completed, the reverse operation is performed to remove the tray 104 from the chamber 100 and the load lock 110 to remove the processed wafer and load a new wafer for processing.

FIG. 1B shows a system similar to that of FIG. 1A, wherein components similar to those shown in FIG. 1A use like reference numerals. In the embodiment of FIG. 1B, the tray 104 does not move into the load lock 110. Instead, in the embodiment of FIG. 1B, the wafer in the loading chamber 120 is removed from the tray 104 and loaded into one of the specially designed wafer hangers 118, 119. The loaded hanger, 118, is then moved to the load lock chamber 110 and the valve 112 is closed. The load lock chamber 110 then becomes a vacuum. Once the proper vacuum level is reached, the valve 102 opens and the wafer hanger is moved to the processing chamber 100 where the wafer is removed from the wafer hanger and placed on the setter 108. The wafer hanger is then removed from the processing chamber 100 to return to the load lock chamber 110, and the valve 102 is closed. Processing chamber 100 is then operated to process the substrates in the chamber.

Meanwhile, at the same time as the above process, another wafer hanger 119 is located in the loading chamber 120 and a new substrate is loaded. The loaded hanger 119 is then moved to the load lock 110, the valve 112 is closed and vacuumed. When the processing of the chamber 100 is completed, the valve 102 is opened and the wafer hanger 118 is moved from the load lock 110 to the chamber 100 to collect the processed substrate, and the chamber 100 for processing The hanger 119 is moved from the load lock chamber 110 to the chamber 100 to lower the new substrate. When both hangers are turned back to the load lock 110, the valve 102 is closed and the chamber 100 is operated to process new wafers. The valve 112 is then opened and the load lock 110 is vented to atmospheric pressure and the hanger 118 is moved to the loading chamber 120 to load a new substrate for unloading and processing the processed wafer.

FIG. 2A is a general schematic diagram depicting major components of a system architecture in accordance with an embodiment of the present invention, showing a damaged substrate repair system installed over the factory interface of the system shown in FIG. In FIG. 2A, elements similar to those shown in FIG. 1A use similar reference numerals except for the 2xx series. In FIG. 2A, the loading chamber 220 is fitted to the first sensing mechanism 244, where a new set of wafers is received by the load chamber, entering and / or exiting the load lock chamber 210. In order to detect wafer damage on the image, a signal is received from a controller 205. In this embodiment, the sensing mechanism 244 is an optical sensor or camera, which is disposed on the damaged wafer recovery system described below. In addition, a second sensing mechanism 246 is provided within the processing chamber 200 to detect damaged wafers. In this embodiment, the sensing mechanism 246 is a monitor of the camera and controller 205 coupled to the image processor. In this embodiment, the camera 246 is located within the load lock 210 and is oriented to look inside the chamber 200 when the gate valve 202 is opened. An illumination source 232 may be provided to illuminate the area seen by the sensing mechanism 246. The illumination source 232 may be located within the load lock 210 or may be provided outside the processing chamber to illuminate the interior through the window 233 or the like. The image processor of the controller 205 may use an image processing program to determine if the wafer is damaged in the chamber 200, where the monitor of the controller 205 allows the operator to confirm or invalidate the decision of the image processor. can do. If the image processor overlooks the damage, the operator can designate the wafer as damaged through the monitor.

The damaged wafer recovery system shown in FIG. 2A has an x-movement gantry 250 that moves the y-movement gantry 252 in the x direction, as indicated by the double-headed arrow labeled X. The y-movement gantry moves the suction head 254 in the y direction, as indicated by the double arrow marked Y. As indicated by the double arrow marked Z, the suction head can also move vertically. In this way, the suction head can be placed on any coordinate on the tray 204. Once the damaged wafer is identified in the processing chamber 200, the tray 204 is moved to the loading chamber 220. Conversely, if a damaged wafer is detected on an incoming or outgoing wafer tray, the tray is held in the load chamber for removal of the damaged wafer. The controller 205 moves the suction head to the position of the damaged wafer and activates the suction pump 365 to remove the damaged wafer from the tray. Sensing mechanism 244 then confirms successful removal of the damaged wafer and the system is back in operation.

FIG. 2B is a general schematic diagram depicting major components of a system architecture in accordance with one embodiment of the present invention, showing a damaged substrate repair system installed over the factory interface of the system shown in FIG. In FIG. 2B, elements similar to those shown in FIG. 1A use similar reference numerals except for the 2xx series. In FIG. 2B, the loading chamber 220 is fitted to the first sensing mechanism 244, where a new set of wafers is received by the load chamber, and the tray 204 entering and / or exiting the load lock chamber 210. To detect wafer damage on the image, a signal is received from the controller 205. In this embodiment, the sensing mechanism 244 is an optical sensor, thru beam sensor, camera, or the like, which is disposed on the damaged wafer recovery system described below. In addition, a second sensing mechanism 246 is provided within the processing chamber 200 to detect damaged wafers. In this embodiment, the sensing mechanism 246 is a monitor of the camera and controller 205 coupled to the image processor. In this embodiment, the camera 246 is located within the load lock 210 and is oriented to look inside the chamber 200 when the gate valve 202 is opened. The illumination source 232 may be located within the load lock 210 or may be provided outside the processing chamber to illuminate the interior through the window 233 or the like. The image processor of the controller 205 may use an image processing program to determine if the wafer is damaged in the chamber 200, where the monitor of the controller 205 allows the operator to confirm or invalidate the decision of the image processor. can do. If the image processor overlooks the damage, the operator can designate the wafer as damaged through the monitor.

The damaged wafer recovery system shown in FIG. 2B has an x-movement gantry 250 that moves the y-movement gantry 252 in the x direction, as indicated by the double-headed arrow marked with X. FIG. The y-movement gantry moves the suction head 254 in the y direction, as indicated by the double arrow marked Y. As indicated by the double arrow marked Z, the suction head can also move vertically. In this way, the suction head can be placed on any coordinate on the tray 204. Once the damaged wafer is identified, the suction head is moved to the location of the damaged wafer and the suction generator is activated to remove the damaged wafer from the tray. Sensing mechanism 244 then confirms successful removal of the damaged wafer and the system is back in operation.

Moreover, in the embodiment of FIG. 2B, the hanger 219 has a mechanism for removing the susceptor 208 in the chamber 200 and moving it to the loading chamber 220. When the image processor or operator identifies the damaged wafer in the processing chamber 200, the hanger 219 is moved to the processing chamber 200 to engage the susceptor 208. The susceptor 208 is then transported to the loading chamber 220. In the loading chamber 220, the suction head is moved to the location of the damaged wafer, and the suction generator is operated to remove the damaged wafer from the susceptor 208. The sensing mechanism 244 then confirms successful removal of the damaged wafer and the system is back in operation.

According to one embodiment of the invention, when the image processor uses an image of the sensor 246 indicating that the wafer is damaged on the susceptor 208, the hanger 219 is used to engage the susceptor and performs a second inspection. To the sensor 244. If the sensor 244 also identifies that the wafer is actually damaged, a hanger can be used to move the susceptor to the station 220 to remove the broken pieces.

According to another embodiment, the system of FIG. 2B has a sensor 244 but no sensor 246. According to this embodiment, when the hanger is moved to the loadlock with a new wafer, the sensor 244 is used to record each position on the hanger occupied by the wafer. Then, when the hanger is sent to the chamber to remove the processed wafer, the sensor 244 is again used to check if all locations on the hanger previously occupied by the wafer are still occupied. If not, this indicates that the wafer is damaged and still in the chamber. The hanger is then sent to take the susceptor and transfer it to the loading chamber 220 to use the suction head to remove the damaged wafer from the susceptor.

2C shows another embodiment, showing a first processing chamber 200 and a second processing chamber 201. A flipping station 221 is located between the first and second processing chambers. This configuration is advantageous when the chamber 210 processes one side of the wafer and the chamber 201 processes the other side of the wafer. Thus, after processing the wafer in the first chamber 200, the tray 204 (or hanger) is moved to the flip station 221 where the wafer on the tray 204 is flipped over. The tray 204 is then moved to the second chamber 201 for processing. When the process is complete in the second chamber, the tray is moved to the unloading chamber 226. Flip station 221 is in standby to provide load locks 216 and 222 on both sides, which is schematically shown in FIG. 2C. In addition, a load lock 223 is provided between the processing chamber 201 and the unloading chamber 226.

In this example, a damaged wafer recovery system is provided to flip station 226. The damaged wafer recovery system may be in the form shown in FIGS. 2A and 2B above. With the above example, various sensors, here sensors 244, 246, 248, communicate with the controller 205 to identify damage to the wafer. For example, if any of the sensors 244, 246, 248 detects a damaged wafer, the tray 204 is moved to a flip mechanism and the suction head 254 is used to remove the damaged wafer from the tray. Before the wafer is flipped and the tray advances to the chamber 201, the sensor 248 is used to verify that the damaged wafer has been completely removed from the tray.

3A is a general schematic diagram depicting major components of a damaged wafer repair system in accordance with one embodiment of the present invention. The damaged wafer recovery system shown in FIG. 3A may be used in any of the above embodiments, or in other mainframe, linear or other system architectures. The recovery system includes a suction head 362 and a mechanism capable of placing the suction head 362 anywhere on the tray 304 (or the hanger or susceptor). In the embodiment of FIG. 3A, the placement mechanism includes a first gantry 364 and a second gantry 366 mounted on the frame 360. Frame 360 may be a frame such as a loading chamber, a flip station, or the like. The first gantry 364 moves the suction head 362 in one linear direction, for example in the X direction, and the second gantry 366 moves the suction head 362 in a linear direction perpendicular to the first gantry, For example, in the Y direction. This is represented by a double arrow in FIG. 3A. The vertical bidirectional arrow also indicates the ability of the suction head 362 to move in the longitudinal direction, ie in the Z direction, to lower and withdraw the suction head from the tray. The flexible tube 368 connects the suction head 362 to the suction pump 365.

Another feature shown in FIG. 3A is a storage and disposal station 370. In this embodiment, if no suction head is used, it is stored at station 370. In addition, once the suction head removes the broken piece of wafer, as shown by the broken wafer 372, the suction head is moved to the station 370, and once the vacuum is removed from the suction head, the remaining wafer piece is removed from the station 370. Discarded).

3B is a general schematic diagram depicting the major components of a damaged wafer repair system according to another embodiment of the present invention. The embodiment shown in FIG. 3B is similar to FIG. 3A, except that in FIG. 3B the (r,) arrangement was used for the placement mechanism, unlike the (x, y) arrangement. That is, instead of moving the suction head 362 using an orthogonal linear direction (ie, Cartesian coordinates), in the embodiment of FIG. 3B the polar coordinates, together with the linear motion arm 376, are positioned in order to place the suction head in a suitable position. By using the angular motion around the rotation axis 374 is used.

4 is a general schematic diagram depicting additional elements of the damaged wafer recovery system shown in FIGS. 3A and 3B. In particular, FIG. 4 shows details of the suction head 462. As shown in FIG. 4, a hood 469 is mounted at the inlet of the suction head 462. Inside the hood there are several recoverable pins 480. The pin is used to break the wafer into small pieces that can be easily removed by the suction head and will not clog into the hose headed to the suction head or pump. Pin 480 is connected to common frame 486 through a hole 484 in hood 469. The common frame 486 is recoverable by the retrieval mechanism 488.

4 also shows a setback extension 481 that prevents the hood 469 from fully contacting or sealing the tray, susceptor or hanger. This allows for sufficient air flow to the inlet, which allows for correct suction to remove the broken pieces. It also reduces heat conduction to the hood, especially since the tray or susceptor is hot up to 300 ° C when taken out after treatment. Because of the setback extension 481, the hood can avoid being heated by contacting the tray or susceptor.

5 illustrates a susceptor used to process a substrate in a system such as that shown above. The susceptor 508 is basically in the form of a plate having a plurality of positions 591 for the wafer. In the center of each seat 591, a hole 593 is provided so that a lift pin can lift the substrate. In this embodiment, the lift pins do not engage directly with the wafer. Instead, a puck 597 is seated at the puck seat 595 provided in the lift pin hole 593. The lift pin engages the puck and lifts the puck, engaging the wafer.

Once the damaged wafer removal system is fitted to the system using the susceptor of FIG. 5, a contrast must be made to avoid sucking the puck when removing the damaged wafer. According to one embodiment, the pin 480 shown in FIG. 4 may be adapted to engage the puck and to hold it in place before starting the suction pump. In this configuration, the pin serves two purposes: the pin is used to break the wafer into smaller pieces when needed and to hold the puck during suction.

Although the present invention has been described in connection with specific embodiments, it is not limited to these embodiments. In particular, various modifications and variations can be made by those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

A system capable of removing a damaged substrate used in a substrate processing system,
A suction head having an inlet;
A placement mechanism to move the suction head to the location of the damaged substrate;
Suction pump;
A flexible tube connecting said suction head to said suction pump.

The system of claim 1, further comprising a hood located at the inlet of the suction head.

3. The system of claim 2, wherein the hood includes a setback extension to direct airflow to the inlet.

The system of claim 1, further comprising a plurality of movable pins extendable around the inlet of the suction head to further break the damaged substrate.

5. The system of claim 4, further comprising a frame coupled to the retrieval mechanism, wherein the plurality of movable pins are commonly connected to the frame.

The system of claim 1, wherein the placement mechanism comprises a first gantry that provides linear motion in one direction and a second gantry that provides linear motion in a perpendicular direction.

The system of claim 1, wherein the placement mechanism includes a rotatable pivot that provides rotational motion and an arm that provides linear motion.

10. The system of claim 1, further comprising a storage and disposal station for storing the suction head when not in use and discarding any remaining scrap removed by the suction head.

The system of claim 1, further comprising an optical sensor coupled to the controller to detect a damaged substrate and to control a placement mechanism to move the suction head over the location of the damaged substrate.

10. The system of claim 9, wherein the optical sensor comprises a camera.

The optical sensor of claim 4, wherein the optical sensor is coupled to the controller to detect a damaged substrate, to control a placement mechanism that moves the suction head above the location of the damaged substrate, and to extend the extendable pin to further break the damaged substrate. The system further comprises.

In a wafer manufacturing system,
Vacuum processing chamber;
A load lock chamber connected to the vacuum processing chamber via a vacuum valve;
A wafer exchange station connected to the load lock station;
Controller;
An optical sensor for sending a signal to the controller;
A placement mechanism connected to the wafer exchange station and movably supporting a suction head having a suction inlet;
A suction pump connected to the suction head,
The controller operative to operate the placement mechanism and the suction pump in accordance with a signal received from the optical sensor.

The method of claim 12, further comprising a susceptor located in the vacuum processing chamber,
In response to a signal received from the optical sensor, the controller operates the placement mechanism to transfer the susceptor to the exchange station and to position the suction head at a specific location above the susceptor.

14. The system of claim 13, further comprising an extendable pin provided around an inlet of said suction head, said controller operating said extendable pin to break a wafer located on said susceptor.

The system of claim 13, wherein the susceptor has a plurality of pucks and the extendable pin is adapted to hold one of the pucks while the suction head removes a piece of damaged wafer.

16. The system of claim 15, further comprising a second optical sensor to transmit a signal to the controller for at least one of a proof of wafer damage or proof of complete removal of the damaged wafer.

The method of claim 12, further comprising at least one tray configured to simultaneously support a plurality of wafers,
In response to a signal received from the optical sensor, the controller operates the placement mechanism to transfer the tray to the exchange station and to place the suction head at a specific location above the tray.

13. The system of claim 12, wherein the exchange station further comprises a flip mechanism adapted to flip the wafer.

13. The system of claim 12, further comprising an illumination source that illuminates the interior of the processing chamber.

A method of removing a broken wafer piece from a plate supporting a plurality of wafers in a manufacturing system,
Analyzing the optical signal to determine if one of the plurality of wafers is broken;
If it is determined that the broken wafer is in position on the plate, transferring the plate to the exchange station, placing the suction head over the broken wafer position, and operating a suction pump to remove the broken wafer piece. How to feature.

21. The method of claim 20,
If it is determined that the broken wafer is in position on the plate, moving the plate to the position of the second optical sensor to verify that the broken wafer is on the plate.