High throughput wafer notch aligner

• US 20080138175A1
• Filed: 12/06/2006
• Published: 06/12/2008
• Est. Priority Date: 12/06/2006
• Status: Active Grant

• Current Assignee: Axcelis Technologies Incorporated
• Original Assignee: Axcelis Technologies Incorporated
• Inventors: Mitchell, Robert J., Ferrara, Joseph
• Granted Patent: US 7,949,425 B2
• Time in Patent Office: Days
• US Class Current: 414/217
• CPC Class Codes: H01L 21/67265 of substrates stored in a container, a magazine, a carrier, a boat or the like
• CPC Class Codes: H01L 21/67745 characterized by movements or sequence of movements of transfer devices
• CPC Class Codes: H01L 21/681 using optical controlling means

Abstract

An ion implantation apparatus, system, and method are provided for a transferring a plurality of workpieces between vacuum and atmospheric pressures, wherein an alignment mechanism is operable to align a plurality of workpieces for generally simultaneous transportation to a dual-workpiece load lock chamber. The alignment mechanism comprises a characterization device, an elevator, and two vertically-aligned workpiece supports for supporting two workpieces. First and second atmospheric robots are configured to generally simultaneously transfer two workpieces at a time between load lock modules, the alignment mechanism, and a FOUP. Third and fourth vacuum robots are configured to transfer one workpiece at a time between the load lock modules and a process module.

Claims

1. An alignment and buffering apparatus for determining an orientation of a plurality of workpieces, the alignment mechanism comprising:

a base;

a workpiece buffering device comprising a plurality of workpiece tray stations aligned generally vertically with respect to one another, wherein each workpiece tray station is operable to selectively support a respective one of the plurality of workpieces in a respective buffer position;

an elevator device operably coupled to the base, wherein the elevator device is operable to individually vertically translate each of the plurality of workpieces from the respective buffer position to a characterization position and to rotate each respective workpiece about an axis associated therewith; and

a characterization device associated with the characterization position, wherein the characterization device is operable to detect one or more characteristics associated with each of the plurality of workpieces when each respective workpiece is at the characterization position.

2. The alignment and buffering apparatus of claim 1, wherein each workpiece tray station comprises:

a plurality of workpiece supports associated with a circumference of the plurality of workpieces; and

a horizontal translation device operably coupled to the plurality of workpiece supports, wherein the horizontal translation device is operable to selectively radially translate the plurality of workpiece supports between a retracted position and an extended position, wherein the plurality of workpiece supports are operable to support the respective workpiece in the retracted position, and wherein the respective workpiece is free to vertically translate with respect to the plurality of workpiece supports in the extended position.

3. The alignment and buffering apparatus of claim 2, wherein the plurality of workpiece supports comprise two or more arcuate support members.

4. The alignment and buffering apparatus of claim 3, wherein the two or more arcuate support members each comprise an arcuate recess having a radius associated with the circumference of the plurality of workpieces, wherein at least a portion of the circumference of the respective workpiece generally rests on the arcuate recess when the plurality of workpiece supports are in the retracted position, and wherein the two or more arcuate support members are generally positioned beyond the circumference of the workpiece when the plurality of workpiece supports are in the extended position, therein generally permitting the elevator device to vertically translate the workpiece to the characterization position when the plurality of workpiece supports are in the extended position.

5. The alignment and buffering apparatus of claim 2, wherein for each workpiece tray station, the elevator device is operable to generally lift the respective workpiece from the plurality of workpiece supports when the plurality of workpiece supports are in the retracted position, and wherein the elevator device is operable to vertically translate the workpiece beyond a plane of the plurality of workpiece supports when the plurality of workpiece supports are in the extended position.

6. The alignment and buffering apparatus of claim 1, further comprising a controller configured to control the workpiece tray stations, elevator device, and characterization device.

7. The alignment and buffering apparatus of claim 1, wherein the characterization position is generally below at least one of the buffer positions.

8. The alignment and buffering apparatus of claim 1, wherein the elevator device comprises an elevator shaft operably coupled to an elevator workpiece support, wherein the elevator shaft is in linear sliding engagement with the base, and wherein the elevator workpiece support is configured to selectively support each of the plurality of workpieces.

9. The alignment and buffering apparatus of claim 8, wherein the elevator shaft is further rotationally coupled to the base.

10. The alignment and buffering apparatus of claim 9, further comprising a motor operably coupled to the elevator shaft, wherein the motor is operable to rotate the elevator shaft about the axis.

11. The alignment and buffering apparatus of claim 10, wherein the motor comprises a servo motor, and wherein the servo motor is configured to determine a rotational position of the elevator shaft with respect to the base.

12. The alignment and buffering apparatus of claim 1, wherein the characterization device comprises an optical sensor, wherein the optical sensor is operable to detect the one or more characteristics of the plurality of workpieces when each workpiece is at the characterization position.

13. The alignment and buffering apparatus of claim 1, wherein the one or more characteristics comprise one or more of a notch in the workpiece, a position of the workpiece, and an indicia associated with the workpiece.

14. An alignment and buffering apparatus, comprising:

a base;

a first workpiece tray station configured to selectively support a first workpiece, therein defining a first buffer position;

a second workpiece tray station configured to selectively support a second workpiece, therein defining a second buffer position, wherein the first buffer position and second buffer position are generally aligned vertically; and

an elevator device operably coupled to the base, wherein the elevator device is configured to selectively translate each of the first workpiece and second workpiece along an axis between the respective first buffer position and second buffer position and a characterization position.

15. The alignment and buffering apparatus of claim 14, wherein the elevator device comprises an elevator shaft coupled to an elevator workpiece support, wherein the elevator shaft is in linear sliding engagement with the base along the axis, and wherein the elevator workpiece support is configured to selectively individually support each of the first workpiece and second workpiece.

16. The alignment and buffering apparatus of claim 15, wherein the elevator shaft is further rotationally coupled to the base.

17. The alignment and buffering apparatus of claim 16, further comprising a motor operably coupled to the elevator shaft, wherein the motor is operable to rotate the elevator shaft about the axis.

18. The alignment and buffering apparatus of claim 17, wherein the motor comprises a servo motor.

19. The alignment and buffering apparatus of claim 16, wherein the characterization device is operable to detect one or more characteristics associated with the first and second workpieces when each respective first and second workpiece is at the characterization position.

20. The alignment and buffering apparatus of claim 19, wherein the characterization device comprises an optical sensor, wherein the optical sensor is operable to detect the one or more visual characteristics of the first and second workpieces when the respective first and second workpiece is at the characterization position.

21. The alignment and buffering apparatus of claim 20, wherein the one or more visual characteristics comprise one or more of a notch in a circumference of the respective first and second workpiece, a position of the respective first and second workpiece, and an indicia associated with the respective first and second workpiece.

22. The alignment and buffering apparatus of claim 21, wherein the position of the respective first and second workpiece comprises one or more of a rotational position of the respective first and second workpiece with respect to the base and a center of the respective first and second workpiece with respect to the elevator workpiece support.

23. The alignment and buffering apparatus of claim 15, wherein the elevator workpiece support comprises a vacuum chuck operable to selectively grip each of the respective first and second workpieces.

24. The alignment and buffering apparatus of claim 14, further comprising a controller operable to control the first and second tray stations, the elevator device, and the characterization device.

25. The alignment and buffering apparatus of claim 14, wherein each of the first and second workpiece tray stations respectively comprise:

a plurality of workpiece supports each having an arcuate recess defined therein, wherein a radius of the arcuate recess is associated with a circumference of the first and second workpieces; and

a horizontal translation device operably coupled to the plurality of workpiece supports and the base, wherein the horizontal translation device is configured to selectively radially translate the plurality of workpiece supports with respect to the axis between a retracted position and an extended position.

26. The alignment and buffering apparatus of claim 25, wherein the arcuate recesses of the respective plurality of workpiece supports are configured to selectively engage at least a portion of the circumference of the respective first or second workpiece when the plurality of workpiece supports are in the retracted position, and wherein a distance between the arcuate recesses of the plurality of workpiece supports is greater than a diameter of the first and second workpieces when the plurality of workpiece supports are in the extended position, wherein the respective first or second workpiece is free to vertically translate with respect to the plurality of workpiece supports when the plurality of workpiece supports are in the extended position.

27. The alignment and buffering apparatus of claim 26, wherein the elevator device is configured to selectively lift the respective first or second workpiece from the respective first or second workpiece tray station when the respective plurality of workpiece supports are in the retracted position, and wherein the elevator device is further configured to selectively translate the respective first or second workpiece along the axis to the characterization position when the plurality of workpiece supports are in the extended position.

28. The alignment and buffering apparatus of claim 24, wherein characterization position is positioned generally vertically below one or more of the first and second buffer positions.

29. A method for aligning and buffering workpieces, the method comprising:

providing an alignment mechanism having first workpiece tray station, a second workpiece tray station, and a vertically-translating elevator device, wherein the first workpiece tray station is aligned generally vertically beneath the second workpiece tray station, and wherein each of the first and second workpiece tray stations comprise a plurality of workpiece supports;

generally concurrently placing first and second workpieces on the plurality of workpiece supports associated with the respective first and second workpiece tray stations;

raising the first workpiece from the plurality of workpiece supports of the first workpiece tray station via the elevator device;

vertically translating the first workpiece to a characterization position via the elevator device;

characterizing the first workpiece;

removing the first workpiece from the alignment mechanism;

raising the second workpiece from the plurality of workpiece supports of the second workpiece tray station via the elevator device;

vertically translating the second workpiece to the characterization position;

characterizing the second workpiece; and

removing the second workpiece from the alignment mechanism.

30. The method of claim 29, wherein generally concurrently placing first and second workpieces on the plurality of workpiece supports comprises lowering the first and second workpieces onto the plurality of workpiece supports when the plurality of workpiece supports associated with both the first and second workpiece tray stations are in a retracted position.

31. The method of claim 30, wherein the first workpiece is raised from the plurality of workpiece supports of the first workpiece tray station when the plurality of workpiece supports of the first workpiece tray station are in the retracted position.

32. The method of claim 31, wherein the characterization position is generally below the first workpiece tray station, wherein vertically translating the first workpiece to the characterization position comprises radially translating the plurality of workpiece supports of the first workpiece tray station from the retracted position to an extended position, and translating the first workpiece between the plurality of workpiece supports of the first workpiece tray station to the characterization position.

33. The method of claim 30, wherein the second workpiece is raised from the plurality of workpiece supports of the second workpiece tray station when the plurality of workpiece supports of the second workpiece tray station are in the retracted position.

34. The method of claim 33, wherein the characterization position is generally below the first workpiece tray station, wherein vertically translating the second workpiece to the characterization position comprises radially translating the plurality of workpiece supports of the first workpiece tray station and second workpiece tray station from the retracted position to an extended position, and translating the second workpiece between the plurality of workpiece supports of the first workpiece tray station and second workpiece tray station to the characterization position.

35. The method of claim 33, wherein the characterization position is generally between the first workpiece tray station and the second workpiece tray station, wherein vertically translating the second workpiece to the characterization position comprises radially translating the plurality of workpiece supports of the second workpiece tray station from the retracted position to an extended position, and translating the second workpiece between the plurality of workpiece supports of the second workpiece tray station to the characterization position.

36. The method of claim 29, wherein characterizing the first and second workpieces comprises:

respectively rotating the first and second workpieces about an axis of the elevator device; and

determining one or more characteristics associated with the respective first and second workpieces during the respective rotation.

37. The method of claim 36, wherein determining the one or more characteristics comprises determining a rotational orientation of the respective first and second workpieces with respect to the alignment mechanism, an offset position of the respective first and second workpiece with respect to the axis, and an indicia associated with the respective first and second workpieces.

38. The method of claim 37, wherein determining the rotational orientation of the respective first and second workpieces comprises:

providing an optical sensor having a beamline directed toward a circumference of the first and second workpieces when the first and second workpieces are at the characterization position;

obtaining a signal from the optical sensor as the circumference of the respective first and second workpiece passes through the beamline of the optical sensor during the respective rotation thereof; and

determining a position of a notch in the circumference of the respective first and second workpiece based on the signal obtained from the optical sensor and a knowledge of dimensional information associated with the notch.

39. The method of claim 38, further comprising:

rotating the respective first and second workpieces to a predetermined rotational position via the elevator device based on the determined position of the notch.

40. The method of claim 38, wherein determining the offset position of the respective first and second workpiece with respect to the axis comprises:

determining a rotational position of the elevator device; and

analyzing the signal obtained from the optical sensor as the circumference of the respective first and second workpiece passes through the beamline of the optical sensor during the respective rotation thereof, and extrapolating an offset vector based on a linearity of the obtained signal and rotational position of the elevator device.