Method and apparatus for inverting samples in a process

• US 5,421,889 A
• Filed: 06/29/1993
• Issued: 06/06/1995
• Est. Priority Date: 06/29/1993
• Status: Expired due to Fees

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Barriss, Louise S., Pollock, John D.
• Primary Examiner(s): Breneman, R. Bruce
• Assistant Examiner(s): LUND, JEFFRIE ROBERT
• Application Number:
  US08/084,415
• Time in Patent Office: 707 Days
• Field of Search: 414/935-941, 118/731, 118/728, 118/723 R, 118/723 VE, 118/723 E, 118/719, 198/400, 198/402, 198/403, 204/298.15
• US Class Current: 118/719
• CPC Class Codes: C23C 16/54 Apparatus specially adapted for continuous coating
• CPC Class Codes: H01L 21/68707 the wafers being placed on a robot blade, or gripped by a gripper for conveyance
• CPC Class Codes: Y10S 414/135 Associated with semiconductor wafer handling
• CPC Class Codes: Y10S 414/14 Wafer cassette transporting
• CPC Class Codes: Y10S 414/141 includes means for gripping wafer

Abstract

The invention provides apparatus and methods for improving systems which expose samples to reactive plasmas, and more particularly for inverting the sample within these systems. The systems are of the type which have one or more process chambers, at least one intermediate chamber, and a robot transport mechanism to transport the sample between the several chambers. The invention includes flipping and gripping assemblies which mount within the intermediate chamber. These assemblies grasp and remove the sample as transported by the robot mechanism, and invert the sample within the intermediate chamber. The inverted sample is re-positioned at the robot mechanism so that the sample can be transported to one or more process chambers for deposition in a "face down" orientation, which reduces contamination.

Claims

1. In a processing system for exposing a sample to reactive plasma, said system having mechanized robot transport means to transport the sample between one or more process chambers and at least one intermediate chamber which provides access to said process chambers, the improvement comprising

A. lifter means having an arm member extending within said intermediate chamber proximal to said robot means,

B. a master clamp for selectively engaging and alternatively releasing the sample being transported by said robot means,

C. a second clamp opposed to the master clamp and coupled with said arm member for selectively engaging and alternatively releasing the sample, and

D. flipper means coupled with said arm member and with said master clamp for selectively rotating said master clamp about a first axis, thereby for inverting and re-inverting the sample.

2. In a processing system of claim 1, the further improvement wherein said arm member is selectively moveable within said intermediate chamber between a first location proximal to said robot means and a second location distal from said robot means.

3. In a processing system of claim 2, the improvement further comprising first drive means coupled with said lifter means for powering said arm member between said first and second locations.

4. In a processing system of claim 1, the further improvement comprising second drive means coupled with said master clamp for powering said master clamp between a sample-engaging position and a sample-releasing position.

5. In a processing system of claim 1, the further improvement comprising third drive means coupled with said flipper means for powering the rotation of said master clamp about said first axis between inverted and re-inverted positions.

6. In a processing system for exposing a sample to reactive plasma, said system having mechanized robot transport means to transport the sample between one or more process chambers and at least one intermediate chamber which provides access to said process chambers, the improvement comprising

A. lifter means having an arm member extending within said intermediate chamber proximal to said robot means,

B. gripper means coupled with said arm member for selectively engaging and alternatively releasing the sample being transported by said robot means,

C. flipper means coupled with said arm member for selectively rotating said gripper means about a first axis, thereby for inverting and re-inverting said transported sample, and

wherein said chamber includes a wall and said arm member is hingedly mounted to said wall, whereby said lifter means rotates said arm member about a second axis which is substantially parallel to said first axis.

7. In a processing system of claim 6, the further improvement wherein said arm member comprises yoke means rigidly attached to said arm member and having a pair of parallel spaced members extending transverse to said second axis and spaced apart to accommodate the sample with engagements at opposed surfaces of the sample.

8. In a processing system of claim 6, the improvement wherein said lifter means further comprises pillow blocks and self-aligning ball bearings for mounting said arm member to said wall and between said ball bearings.

9. In a processing system for exposing a sample to reactive plasma, said system having mechanized robot transport means to transport the sample between one or more process chambers and at least one intermediate chamber which provides access to said process chambers, the improvement comprising

A. lifter means having an arm member extending within said intermediate chamber proximal to said robot means,

B. gripper means coupled with said arm member for selectively engaging and alternatively releasing the sample being transported by said robot means,

C. flipper means coupled with said arm member for selectively rotating said gripper means about a first axis, thereby for inverting and re-inverting said transported sample,

D. end effector means mechanically coupled to said robot means for securing the sample during transportation in said intermediate chamber, said end effector means forming a stop for centering said transported sample and having a spring-loaded clamp to bias the transported sample against said stop, and

E. release actuator means for selectively limiting the bias applied to the sample by said spring-loaded clamp.

10. In a processing system of claim 9, the further improvement wherein said release actuator means comprises a selectively controlled pneumatic push rod and a first linkage assembly responsive to said push rod, for alternatively positioning said linkage assembly between a first position spaced away from said clamp, and a second position abuttingly coupled to said clamp, said end effector means moving in conjunction with said robot means whereby a movement of said robot means decouples said clamp from the sample.

11. In a processing system of claim 9 wherein the sample has an exclusion zone, said exclusion zone being a portion of the sample which may come into physical contact with said system, the further improvement wherein said end effector means secures the sample exclusively within said exclusion zone.

12. In a processing system for exposing a sample to reactive plasma, said system having mechanized robot transport means to transport the sample between one or more process chambers and at least one intermediate chamber which provides access to said process chambers, the improvement comprising

A. lifter means having an arm member extending within said intermediate chamber proximal to said robot means,

B. gripper means coupled with said arm member for selectively engaging and alternatively releasing the sample being transported by said robot means,

C. flipper means coupled with said arm member for selectively rotating said gripper means about a first axis, thereby for inverting and re-inverting said transported sample, and wherein said gripper means comprises actuated pins and clamp means suspended from said arm member by said actuated pins, said actuated pins being slideably connected to said arm along said first axis, said clamp means having opposed jaws which respond to the axial motion of said pins along said first axis, said jaws engaging the sample in response to a first axial motion of said pins and releasing the sample in response to a reverse axial motion of said pins.

13. In a processing system of claim 12, the further improvement comprising second drive means coupled with said gripper means for actuating said pins in said first and said reverse axial motions, and, thereby, for moving said jaws between engage and release conditions.

14. In a processing system of claim 12, the further improvement comprising rotatable bearings coupled to said arm member, said actuated pins being slideably connected to said rotatable bearings.

15. In a processing system for exposing a sample to reactive plasma, said system having mechanized robot transport means to transport the sample between one or more process chambers and at least one intermediate chamber which provides access to said process chambers, the improvement comprising

A. lifter means having an arm member extending within said intermediate chamber proximal 19 said robot means,

B. gripper means coupled with said arm member for selectively engaging and alternatively releasing the sample being transported by said robot means.

C. flipper means coupled with said arm member for selectively rotating said gripper means about a first axis, thereby for inverting and re-inverting said transported sample, and wherein said lifter means comprises yoke means rigidly attached to said arm member and having bifurcated spaced members extending transverse to said first axis, said gripper means further comprising a pair of opposed clamps, each of said clamps being respectively suspended from and rotatably fixed on one of said spaced members by an associated actuated pin that is slideably attached to said one of said spaced members and along said first axis, and each clamp having associated opposed and coacting jaw members which respond to the axial motion of said associated actuated pin along said first axis, said jaw members engaging the sample in a first axial motion of said pin and releasing the sample in a second reverse axial motion of said pin, said opposed clamps of each pair being spaced apart parallel to said first axis to accommodate the dimension of the sample therebetween, with each of said associated opposed jaw members arranged to engage and release the thickness of the sample therebetween.

16. In a processing system of claim 15, the further improvement wherein said gripper means comprises opposed linkage members and opposed motor members, each of said linkage members being pivotably attached to a respective one of said spaced members and having a first end hingedly affixed to said associated actuated pin and a second end hingedly affixed to a respective one of said motor members, said gripper means further having common drive means hingedly affixed to said motor members to provide concerted engage and release movements of said pair of opposed clamps.

17. In a processing system of claim 16, the further improvement wherein said common drive means comprises a rigid disc and a gripper drive for selectively rotating said disc about a third axis, said motor members being affixed to said disc on respective opposed sides relative to said third axis whereby said motor members and said linkage members move substantially symmetrically about said third axis.

18. In a processing system of claim 15, the further improvement wherein said flipper means comprises

A. slave linkage rigidly coupling said pair of opposed clamps for concerted motion about said first axis,

B. a flipper belt coupled to one of said associated pins, and

C. flipper drive means for selectively rotating said flipper belt and, thereby, rotating said associated pin and said pair of opposed clamps about said first axis.

19. In a processing system of claim 18, the further improvement wherein said flipper means comprises flipper drive means for selectively rotating said flipper belt, thereby rotating said pair of opposed clamps about said flipper axis.

20. In a processing system of claim 15, the further improvement wherein said chamber includes a wall and said arm member is hingedly mounted to said wall for rotating said arm member within said intermediate chamber.

21. In a processing system of claim 15, the further improvement wherein the sample has an exclusion zone, said exclusion zone being a portion of the sample which may come into physical contact with said system, the further improvement wherein said jaw members engage the sample exclusively within said exclusion zone.

22. In a processing system for exposing a sample to reactive plasma, said system having mechanized robot transport means to transport the sample between one or more process chambers and at least one intermediate chamber which provides access to said process chambers, the improvement comprising

A. lifter means having an arm member extending within said intermediate chamber proximal to said robot means:

B. gripper means .coupled with said arm member for selectively engaging and alternatively releasing the sample being transported by said robot means

C. flipper means coupled with said arm member for selectively rotating said gripper means about a first axis, thereby for inverting and re-inverting said transported sample, and wherein the sample has a primary axis dividing the sample into first and second portions, the further improvement wherein said gripper means engages the sample such that said first axis is offset from said primary axis by a preselected dimension, and whereby said inverted sample is spaced at a position of approximately two times the preselected dimension.

23. In a processing system for exposing a sample to reactive plasma, said system having a mechanized robot transport means to transport the sample between one or more process chambers, and having at least one intermediate chamber which includes a wall and provides access to said process chambers, the improvement comprising

A. lifter means having a rigid yoke hingedly attached to said wall, and further having a lifter drive to selectively rotate said yoke about a rotation axis, said yoke forming bifurcated first and second opposed arms which extend transverse to said rotation axis, the ends of said arms forming a second axis that is substantially parallel to said rotation axis,

B. gripper means supported by said yoke and having first and second opposed clamps suspended, respectively, by first and second actuated pins, each of said pins being slideably connected axially to a respective one of said arms and along said second axis, and further being rotatable about said second axis, said clamps having jaws which respond to the axial motion of said pins wherein said jaws grasp the sample in a first axial motion and release the sample in a reverse second axial motion, said gripper assembly further having a gripper drive to selectively move said pins in said first and second axial motions, and

C. flipper means having a support rigidly connecting said clamps and a flipper drive to selectively rotate at least one of said clamps about said second axis, said lifter means being selectively rotatable between a first position in which said clamps grasp and alternatively release the sample as transported by said robot means, and a second position in which the sample is suspended away from said robot means and said flipper drive inverts and alternatively re-invert the sample.

24. In a processing system of claim 23 further comprising bearing means coupled to each of said opposed arms, each of said pins being slideably connected to said bearing means along said second axis, each of said pins further being connected to a respective one of said clamps and rotatable about said second axis in concert with said clamps.