KR100442478B1 - Wafer processing system including a robot - Google Patents

Abstract

Wafer processing systems use modules such as vertically installed reactors, load locks and cooling stations to occupy minimal floor space. In addition, floor space is further saved by using a loading station that uses rotational motion to move the wafer carrier into the load lock. The wafer processing system includes a robot with extension, rotation and vertical movement to access modules installed vertically. The robot is internally cooled and has a heat-resistant end effector that allows the robot to be used even in high temperature semiconductor processing.

Description

Wafer processing system including a robot {WAFER PROCESSING SYSTEM INCLUDING A ROBOT}

Dedicated wafer processing systems are used to process semiconductor wafers into electronic devices. In some of these systems, a carrier containing a wafer is loaded into a loading station and delivered to a load lock. The robot then picks up the wafer from the carrier and moves the wafer to a reactor (or also referred to as a processing chamber). The wafer is processed in the reactor according to the usage. In chemical vapor deposition reactors, for example, a thin film of insulating material is typically deposited on a wafer to separate one layer of the wafer from the layer on which it is placed. Once the film is deposited, the robot picks up the wafer and transfers it back to the carrier of the load lock. The carrier then exits the load lock and returns to the loading station.

U. S. Patent No. 5,882, 165 to Maydan et al. Discloses a wafer processing system in which a reactor and other system modules are horizontally coupled (ie, modules are spread horizontally). The disadvantage of horizontally coupled systems is that the total floor space occupied by the wafer processing system increases as other modules, such as reactors and cooling stations, are added to the system. It is highly desirable to have a wafer processing system that occupies a minimum floor space because floor space is typically insufficient and expensive in semiconductor manufacturing clean rooms and facility areas. In addition, some components of horizontally coupled systems (eg pumps) typically need to be installed in remote locations due to floor space limitations. Small wafer processing systems are preferred because such systems are moved, installed and operated in a single unit in a small proximity area, thereby eliminating the need for complicated connections to components located at remote locations.

Robots are used to automate the movement of wafers between modules in conventional wafer processing systems. One example of a commercially available wafer processing robot is the SHR3000 robot ("SHR3000 robot") of JEL Corporation (telephone 81-849-62-6590) located in Hiroshima, Japan. The SHR3000 robot can rotate 340 °, have a vertical movement of 200 mm, and extend the arm to 390 mm in the horizontal plane. Like conventional wafer processing robots, the SHR3000 cannot easily access newly processed wafers in very hot reactors without additional waiting time until the reactor cools down. This is particularly problematic in high temperature wafer processing applications such as quenching ("RTP") where the reactor can reach temperatures up to 1200 ° C. In addition, the 200 mm vertical movement of the SHR3000 robot is not suitable for accessing vertically installed modules. It is desirable to have a wafer processing robot capable of withstanding high temperatures and accessing vertically installed modules that vary in height.

The present invention relates generally to systems and robots used in semiconductor device fabrication, particularly wafer processing.

1A and 1B are side and front views, respectively, of a wafer processing system according to the present invention.

2A and 2B are side and front views, respectively, of a loading station according to the present invention.

3 is a cross-sectional view of the bars used in the loading station shown in FIG. 2A.

4A is a functional "X-ray" diagram of a wafer processing robot according to the present invention.

4B is an enlarged view of a portion of the robot shown in FIG. 4A.

4C and 4D are "X-ray" front views of a robot in one embodiment of the present invention.

5 is a block diagram of a control system for controlling the wafer processing system shown in FIGS. 1A and 1B.

6A-6E schematically illustrate the movement of the platform in the loading station shown in FIGS. 2A and 2B.

7A and 7B are side views of the loading station shown in FIGS. 2A and 2B.

8A-8F are side views of the wafer processing system shown in FIG. 1A showing the movement of the wafer from the carrier of the load lock to the reactor.

9 is a functional diagram of a sensor configuration for tracking the position of the platform in the loading station shown in FIGS. 2A and 2B.

10A and 10B are side views of the loading station and load lock in one embodiment of the present invention.

11A is a perspective view of a load lock and platform in accordance with the present invention.

FIG. 11B is a side cross-sectional view of the load lock and platform shown in FIG. 11A.

The present invention relates to a wafer processing system that occupies a minimum floor space. In one embodiment of the present invention, a plurality of reactors are installed vertically (ie vertically coupled) to save floor space. The present invention also uses vertically installed load locks and cooling stations. Floor space can be further reduced by using a loading station that uses rotational movement to move the wafer carrier to the load lock.

The present invention includes a robot for moving a semiconductor wafer in a wafer processing system. In addition to extending and rotating in a horizontal plane, the robot has a vertical range of motion that allows the robot to access vertically installed reactors, load locks, cooling stations and other modules. The robot is internally cooled and supports the wafer using a heat-resistant end-effector (ie, a “finger” to lift the wafer) that allows the robot to be used in high temperature semiconductor manufacturing processes as well.

Other uses, advantages and modifications of the invention will be apparent to those skilled in the art upon reference to this specification and the accompanying drawings.

1A and 1B are side and front views, respectively, of a wafer processing system 100 according to the present invention. System 100 includes a loading station 10, a load lock 12, a transmission room 20, a robot 21, reactors 30 and 40 and a cooling station 60. The loading station 10 has platforms 11A and 11B that support a wafer carrier, such as the wafer carrier 13, and move up into the load lock 12. Although three platforms are used in this embodiment, the present invention is not limited thereto. In addition, two platforms may be used as additional platforms to increase throughput. The carrier 13 is a removable wafer carrier capable of moving up to 25 wafers at a time. Other types of wafer carriers can also be used, including fixed wafer carriers. The wafer carrier is loaded on the platforms 11A and 11B by using manual or automatic guide mechanism (“AGV”).

As an example, moving the wafer to the load lock 12 using the carrier 13 on the platform 11A is shown here, but the same applies to moving other wafer carriers using the platform 11B. . In addition, since the platforms 11A and 11B are structurally and functionally the same, the reference to the platform 11A also applies to the platform 11B. 2A and 2B showing side and front views of the loading station 10, the platform 11A includes a drive bar coupled to the triangular block 207 through a bearing 217. Motor 205 is mechanically coupled to adapter block 219 using flexible coupler 206. The adapter block 219 is fixedly attached to the triangular block 207. By rotating the adapter block 219, the motor 205 rotates the triangular block 207, and the platform 11A now rotates around the pole 208. The rotation of the platform 11A around the pole 208 is shown in FIGS. 6A-6E. 6A-6C show, in order, the front view of platform 11A as it rotates from position 610 to position 611 in the direction indicated by arrow 613. 7A shows a side view of the loading station 10 when the platform 11A is in position 611. 6C shows a front view of the platform 11A as it rotates from position 611 to position 612 in the direction indicated by arrow 614. 7B shows a side view of the loading station 10 when the platform 11A is in position 612.

Referring to FIG. 2B, the belt 11 is positioned so that the opening 601 of the wafer carrier 13 into which the wafer is inserted faces the robot 21 as the platform 11A rotates around the pole 208 (FIGS. 6A-6E). 202 is wound through a fixed center pulley 204, a fixed platform pulley 201 and an idler 203. The tension of the belt 20 is set by adjusting the idler 203.

Referring to FIG. 9, the position of the platform 11A in the loading station 10 is tracked using the sensor 901 and the flag 905. The flag 905 is attached at a designated position on the triangular block 207. The position at which the flag 905 passes through the sensor 901 is known as the "home" position. In one embodiment, the output of sensor 901 is coupled to motor controller 902 via line 903. The output of the motor 205, which may also be an encoder output, is also coupled to the motor controller 902 via line 904. When the flag 905 passes through the sensor 901, the sensor 901 outputs a "home signal" to the motor controller 902 indicating that the triangular block 207 is in the home position. Motor controller 902 determines the number of revolutions of motor 205 after receiving the home signal by monitoring line 904. Since the position of the platform 11A in relation to the home position is specified, the position of the platform 11A can be tracked by the motor controller 902 as the platform 11A rotates around the pole 208.

As shown in FIG. 7B, the cam 212 engages the slotted disk 213 when the platform 11A is in position 612. The cam 212 is attached to the drive bar 209 and the drive bar is now attached to the platform 11A. Once motor controller 902 indicates that platform 11A is in position 612, atmospheric pressure is provided to pneumatic cylinder 210 to push piston 211 upwards. As a result, the slotted disk 213 engages the cam 212 to push the platform 11A into the load lock 12 as shown in FIG. 2A. Bar 209 has a cross section as shown in FIG. 3 taken along section III-III of FIG. 2A to prevent platform 11A from rotating during vertical movement. The atmospheric pressure provided to the pneumatic cylinder 210 to prevent the wafer carrier 13 from hitting the platform 11A is initially provided with a high pressure and gradually reduced as the platform 11A approaches the load lock 12. Adjusted.

Rotational movement of platform 11A, 11B to position 612 minimizes floor space occupied by loading station 10. As will be apparent from FIG. 2B, the loading station 10 occupies just the right area to accommodate the number of platforms used, and the number of platforms used in the particular embodiment shown in FIG. 2B is three.

In one embodiment, the platform of the loading station 10A shown in FIG. 10A is not lifted into the load lock 1012. In the loading station 10A, the motor 205A, the flexible coupler 206A, the adapter block 219A and the triangular block 207A are functionally and structurally identical (ie, to the corresponding portions of the loading station 10). Motor 205A is identical to motor 205, and so forth). The platform 1010A is identical to the platform 11A except that it does not have a long drive bar such as the drive bar 209 of the platform 11A. Contrary to the operation of platform 11A at loading station 10, platform 1010A is not lifted into load lock 1012. Instead, platform 1010A is rotated to a position at which platform 1010A is inserted into load lock 1012 ("load lock position"). In FIG. 10A, the load lock position is just below the load lock 1012. Once the platform 1010A is in the load lock position, the load lock 1012 is lowered to put the platform 1010A therein as shown in FIG. 10B. Therefore, a robot (not shown) of the transmission chamber 1020 may access the wafer of the wafer carrier 1013. The load lock 1012 is raised and lowered using a conventional structure. For example, the load lock 1012 may be fitted to the ball screw and raised by rotating the ball screw using a motor. As in the loading station 10, the rotational movement of the platform 1010A minimizes the floor space requirements of the loading station 10A.

As shown in FIG. 2A, the load lock 12 is hung in the transmission chamber 20 and is also supported by the pole 208 via hinges 215 and 216. The pole 208 rotates freely through the hinge 215, the hinge 216 and the bearing 218 such that vibrations from the motor 205 are not transmitted into the load lock 12. 11A is a perspective view of the load lock 12. In FIG. 11A, the pole 208 and other components of the system 100 are not shown for brevity. The load lock 12 includes a viewing window 1102 on the side 1105 to allow visual inspection of the interior of the load lock 12. Visible window 1102 is composed of a transparent material, such as quartz. Referring to FIG. 11B, which shows a partial side cross-sectional view of the load lock 12, the viewing window 1102 is fastened to the load lock 12 using bolts 1103. A peripheral seal 1106 (eg an O-ring or lip seal) is provided between the sighting window 1102 and the side 1105 to form a vacuum seal. Similarly, the load lock 12 is fastened to the transmission chamber 20 using the bolt 1104. The peripheral seal 1107 between the load lock 12 and the transmission chamber 20 forms a vacuum seal. When the platform 11A is above the load lock 12, the peripheral seal 214 (FIG. 11B) on the platform 11A contacts the bottom opening of the load lock 12. The pneumatic cylinder 210 pushes the platform 11A into the load lock 12 such that the seal 214 presses the load lock 12 to form a vacuum seal during processing requiring a vacuum. In addition, the vacuum in the load lock 12 pulls the platform 11A into the load lock 12 to further improve the vacuum seal. Reduction of floor space is achieved in this particular embodiment by vertically installed load locks 12 above the loading station.

According to the invention, a robot 21 is provided for transferring wafers to or from the modules of system 100, such as reactors 30 and 40, cooling station 60 and load lock 12. do. 4A shows an “X-ray” view of one embodiment of the robot 21. In order to improve the simplicity of the representation by showing all relevant parts of the robot 21 in one figure, FIG. 4A is a functional representation of the robot 21 and does not represent actual partial placement. For example, the actual position of the ball screw 402 relative to the position of the linear guides 405A, 405B is shown in the front view shown in FIG. 4C. Of course, the present invention is not limited to the particular portions, structures and arrangements shown in FIGS. 4A-4C. As shown in FIG. 4A, the z-axis (ie, vertical motion) motor 401 rotates mechanically coupled to the ball screw 402 through the belt 451. Collar 404 is loaded on ball screw 402 and driven by the ball screw. In this embodiment, the z-axis motor 401 is model part number SGM-04A314B of Yaskawa Electric (telephone number 81-93-645-8800) located in Fukuoka, Japan, and the ball screw 402 is THK Corporation located in Tokyo, Japan. Model part number DIK2005-6RRG0 + 625LC5 from Limited (tel. 81-3-5434-0300). Other conventional ball screws and motors can also be used. A support mechanism 452 (eg THK part number FK15) supports the ball screw 402. Vertical driver 403 mounted on collar 404 may be moved up or down using z-axis motor 401 to drive collar 404 through ball screw 402. The vertical driver 403 slides in the opposite direction to the wear ring 453. In general, the wear ring prevents the metal from contacting the metal and absorbs the transverse rod. In one embodiment, wear ring 453 is type part number GR7300800-T51 of Busak + Shamban (Internet website “www.busakshamban.com”). The robot 21 also has a harmonic gear that can take the form of part number SHF-25-100-2UH of Harmonic Drive Systems Inc. (telephone number 81-3-5471-7800) located in Tokyo, Japan ( 461).

As shown in FIG. 4B, which is an enlarged view of a portion of the robot 21 defined by dashed lines IV-IV shown in FIG. 4A, the seal 418 is rotated with the vertical driver 403 to form a vacuum seal. Surround (415). Seal 418 may have a seal form that does not expand or compress into a vacuum sealed moving portion. For example, the seal 418 may be an o-ring, lip seal or t-seal (opposite to bellows). In one embodiment, the seals 418 are type part numbers TVM300800-T01S, TVM200350-T01S of Busak + Shamban. In the prior art, bellows has been used in wafer processing robots to form a vacuum seal around a moving portion, such as a vertical driver 403. Since the bellows expands and compresses into the moving part, the bellows must be made larger when used with the moving part having a long range of motion. For this reason, the bellows becomes impractical in the semiconductor processing robot having a motion range larger than 200 mm. In one embodiment of the robot 21, using the seal 418 instead of the bellows, the vertical driver 403 may rise to 350 mm. Therefore, the robot 21 can access a plurality of modules installed vertically. The vertical driver is stabilized using linear guides 405A (FIGS. 4A and 4C), 405B (FIG. 4C) to hold the seal 418 in place when the vertical driver 403 is moved up and down (eg THK part number HSR25LBUUC0FS + 520LF-II).

Referring to FIG. 4A, the robot 21 includes an end effector 406 for picking up and placing a wafer, which is made of a heat resistant material such as quartz. End effector 406 is fixedly attached to attachment block 407 to accommodate various end effectors. Block 407 is attached to arm 418 and rotates about axis 410. Arm 408 rotates about axis 411 and is attached to arm 409. As shown in FIG. 4D, conventional belt and pulley configurations that include pulleys 455-458 and belts 459-460 include arm 409, arm 408, and block 407 (which are pulleys 458). Mechanically join together). End effector 406 attached to block 407 may be extended or retracted along a straight line by rotating the pulley using extension motor 413 (FIG. 4A) (e.g., Yaskawa Electric's part number SGM-02AW12). Can be. The entire arm assembly, consisting of arm 409, arm 408, block 412 and end effector 406, rotates rotation motor 414 (FIG. 4A) to rotate rotation driver 415 through belt 454. (Eg, Yaskawa Electric's part number SGM-02AW12) can be used to rotate around the axis 412. 4C is a front view showing the arrangement of the z-axis motor 402, linear guides 405A, 405B, extension motor 413, rotation motor 414, and ball screw 402 in one embodiment of the robot 21. to be.

Referring to FIG. 4A, an inlet 416 is provided for the coolant to flow through the cooling channel 417 (also shown in FIG. 4B) and cool the robot 21 during high heat treatments such as RTP. Conventional coolants including water, alcohols and cooled gases can be used. The use of internal cooling and heat resistant end effectors in the robot 21 reduces the processing time of the system 100 because the robot 21 can transfer wafers into and out of the reactor without waiting for the reactor or wafer to cool.

8A-8F show side views of the system 100 showing the movement of the wafer 22 from the carrier 13 inside the load lock 12 to the reactor 30 (or 40). Once the carrier 13 is inside the load lock 12, the robot 21 of the transmission chamber 20 rotates and descends toward the load lock 12 (FIG. 8A). The robot 21 extends the end effector 406 to pick up the wafer 22 from the wafer carrier 13 (FIG. 8B). The robot 21 then contracts (FIG. 8C), rotates towards reactor 30 (FIG. 8D), raises to position the wafer 22 in alignment with the reactor 30 (FIG. 8E), and gates. The wafer 22 is positioned in the reactor 30 through the valve 31 (FIG. 8F). The robot 21 then contracts, and then the gate valve 31 is closed to start processing the wafer 22.

Referring to FIG. 1A, reactors 30 and 40 in this particular embodiment are quenched ("RTP") reactors. However, the present invention is not limited to a particular type of reactor, and semiconductor processing reactors such as those used for physical vapor deposition, etching, chemical vapor deposition, and ashing can be used. Reactors 30 and 40 may also have the form disclosed in co-owned U.S. Patent Application No. [Representative Case No. M-7773], "Heat Resistant Single Furnace", filed on the same date as this specification; The contents of this patent application are incorporated herein by reference in their entirety. Reactors 30 and 40 are installed vertically to save floor space. The reactors 30 and 40 are caught by the transmission chamber 20 and supported by the support frame 32. Process gas, coolant and electrical connections are provided through the rear end of reactors 30 and 40 using interface 33.

The pump 50 shown in FIG. 1A is provided for use in a process requiring vacuum. If the combined volume of reactors 30, 40 is much less than the combined volume of load lock 12, cooling station 60, and transmission chamber 20, the total volume of system 100 (ie, load lock ( 12), a single pump 50 may be used to evacuate and evacuate the air from the cooling station 60, the transmission chamber 20, the combined volume of the reactor 30 and the reactor 40). If not, additional pumps, such as pump 50, may be required to vent air separately from reactors 30 and 40. In this particular embodiment, the combined volume of the load lock 12, cooling station 60 and transmission chamber 20 is approximately 150 liters, whereas the total volume of reactors 30 and 40 is approximately 2 liters so that The pump 50 is enough. In other words, since the combined volume of reactors 30 and 40 is insignificant relative to the total volume of system 100, reactors 30 and 40 do not significantly affect the pressure in system 100. Thus, no separate pump is required to control the pressure in reactors 30 and 40.

After the wafer 22 has been processed in a well known manner within the reactor 30 (or 40), the gate valve 31 is opened so that the robot 21 moves the wafer into the cooling station 60 (FIG. 1A). . Since the newly processed wafer has a temperature of 200 ° C. or more and can dissolve or damage the conventional wafer carrier, a cooling station 60 is provided to cool the wafer before placing the wafer back into the wafer carrier in the load lock 12. do. In this embodiment, the cooling station 60 is installed vertically above the load lock 12 to minimize the floor space area occupied by the system 100. The cooling station 60 includes a shelf 61 that is cool using liquid to support a plurality of wafers at one time. Of course, two shelves are shown in FIG. 1A, but different numbers of shelves may be used to increase the throughput where appropriate.

The wafer 22 is then picked up from the cooling station 60 and relocated to the first groove of the carrier 13 using the robot 21. The platform 11A is lowered from the load lock 12 so that the other platform rotates from the position to move the next wafer carrier into the load lock.

5 shows a block diagram of a control system 530 used in system 100. Computer 501 communicates with controller 520 using Ethernet link 502 to input / output (“I / O”) controller 521. The I / O controller 521 is a digital I / O such as (a) a serial port 522, (b) a sensor for communicating with a robot, temperature, pressure and motor controller (e.g., the motor controller shown in FIG. 9). Digital I / O 523 for controlling O lines, (c) analog I / O 524 for controlling devices driven by analog signals such as mass flow controllers, throttle valves, and (d) Various I / O boards can be accommodated, including relay boards 525 for configuring or breaking a series of signal lines, such as interlock lines. Components constituting the controller 520 are commercially available from Koyo Electronics Industries Co., Ltd. (telephone number 011-81-42-341-3115) located at 1-171, Tenjin-cho, Tokyo, 187-0004, Kodaira, Japan. Control system 530 uses conventional control software to operate and monitor various components of system 100. The system 100 may also use conventional control hardware and software, such as available from National Instruments Corporation (Internet Web site “www.ni.com”) in Austin, Texas, USA.

The foregoing description of the invention is for the purpose of description and not of limitation. The invention is disclosed in the following claims.

Claims (9)

In a robot used in a wafer processing system, An end effector attached to the arm of the robot and composed of a heat resistant material; A first motor for rotating the robot; A second motor for raising and lowering the robot; A third motor extending the end effector; A cooling mechanism in the robot; A vertical driver coupled to the second motor; And A seal surrounding the vertical driver, And the seal is selected from the group consisting of an o-ring, a lip seal, and a t-seal. The method of claim 1, And the end effector is made of quartz. The method of claim 1, The cooling mechanism is a robot, characterized in that it comprises a cooling channel. delete delete In a wafer processing system, Providing a robot having extension, rotational and vertical movements and having a cooling mechanism, an end effector made of a heat resistant material, and a drive member; Rotating the end effector towards a first position; Using the end effector to pick up a wafer from a wafer carrier on the first location; Rotating the end effector towards a second position; And Positioning the wafer on the second position; The drive member includes a seal surrounding a portion of the drive member to provide the vertical movement of the end effector and to allow the robot to operate in a vacuum, Wherein the seal is selected from the group consisting of an o-ring, a lip seal, and a t-seal. The method of claim 6, And wherein said second position is a reactor selected from the group consisting of a quenching reactor, a deposition reactor and an etching reactor. The method of claim 6, The robot is lifted to position a wafer on the second position. The method of claim 8, The robot is raised 200 mm.