Apparatus for alignment of automated workpiece handling systems

• US 6,763,281 B2
• Filed: 06/13/2001
• Issued: 07/13/2004
• Est. Priority Date: 04/19/1999
• Status: Expired due to Term

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Schauer, Ronald Vern, Lappen, Alan Rick
• Primary Examiner(s): Tran, Khoi H.
• Application Number:
  US09/881,854
• Publication Number:
  US 20020021959A1
• Time in Patent Office: 1,126 Days
• Field of Search: 700/213, 700/214, 700/218, 414/217, 414/222.01, 414/222.02, 414/222.13, 414/226.05, 414/935, 414/936, 414/937, 414/938, 414/939, 414/940, 206/454, 206/711, 206/710, 356/400
• US Class Current: 700/218
• CPC Class Codes: B23Q 17/24 using optics or electromagnetic waves
• CPC Class Codes: B23Q 3/186 Aligning devices
• CPC Class Codes: H01L 21/67259 Position monitoring, e.g. misposition detection or presence detection
• 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 21/6732 Vertical carrier comprising wall type elements whereby the substrates are horizontally supported, e.g. comprising sidewalls
• CPC Class Codes: H01L 21/67775 Docking arrangements
• CPC Class Codes: H01L 21/681 using optical controlling means
• CPC Class Codes: Y10S 414/137 including means for charging or discharging wafer cassette

Abstract

An alignment tool, method and system are provided for aligning a robot blade in a workpiece handling system, in which the tool comprises a frame or fixture adapted to be supported by a transfer chamber support surface or other support surface in the system, in which the frame has one or more non-contact distance sensors positioned to measure the distance of a workpiece or robot blade from the sensor or a predetermined reference point or surface. In one embodiment, the frame is used to align a robot blade relative to a robot support alignment surface in a robot chamber. In another embodiment, the frame emulates a workpiece cassette and the distance sensors provide an output to align the robot blade to a cassette support alignment surface. As a consequence, accidental scratching and breakage of workpieces such as semiconductor wafers and display substrates may be reduced or eliminated. In another embodiment, positions of distance sensors may be readily repositioned to accommodate alignment procedures for different sized wafers or other workpieces.

Claims

1. An alignment tool for aligning a robot blade carrying a workpiece in a workpiece handling system, and a base plane defined by a platform of said system, comprising:

a frame having a base adapted to be supported by said platform of said system, said frame further having a plurality of sensor mountings; and

a plurality of non-contact distance sensors mounted to said sensor mountings;

wherein said frame defines an opening positioned between said base and said sensors, said opening being sized sufficiently to admit a target carried by said robot blade between said sensors and said base and wherein said sensors are positioned by said sensor mountings to measure the orientation of said target carried by said robot blade relative to said base plane.

2. The alignment tool of claim 1 wherein said system includes a chamber having a floor and a robot carrying said robot blade, and wherein said platform includes said floor of said chamber and said floor defines said base plane.

3. The alignment tool of claim 2 wherein said base includes a plurality of legs adapted to engage said floor.

4. The alignment tool of claim 3 wherein said base includes a base plate carried by said plurality of legs, said frame further including a top plate carrying said sensor mountings, and a plurality of brackets spacing said top plate above said base plate.

5. The alignment tool of claim 1 wherein said target defines a plane and said plurality of non-contact distance sensors includes three sensors, each sensor being positioned to measure the distance between that sensor and a separate location on said target plane to determine the spatial orientation of said target plane relative to said base plane.

6. The alignment tool of claim 5 wherein each sensor includes an optical sensor.

7. The alignment tool of claim 6 wherein each sensor includes a laser adapted to emit a laser beam onto said target.

8. An alignment tool for aligning a robot blade carrying a workpiece in a workpiece handling system, and a base plane defined by a platform of said system, said platform having a support surface, comprising:

a frame adapted to be supported by said platform support surface, said frame having a reference surface and a first support surface positioned to engage said platform support surface and to support said reference surface a first predetermined distance from said platform support surface; and

a first distance sensor positioned to measure the distance of said reference surface from said sensor and to measure the distance of a target from said sensor, wherein said target is adapted to be carried by said robot blade.

9. The alignment tool of claim 8 wherein said distance sensor is carried within said frame.

10. The alignment tool of claim 8 wherein said distance sensor includes a laser head.

11. The alignment tool of claim 8 wherein said first distance sensor is positioned to measure the distance of a first location of said reference surface from said sensor and to measure the distance of a first location of said target from said sensor, said tool further comprising a second distance sensor positioned to measure the distance of a second location of said reference surface from said second sensor and to measure the distance of a second location of said target from said second sensor.

12. The alignment tool of claim 11 wherein said system has a mechanism for adjusting the orientation of said robot blade along a first direction, wherein said first and second sensors are disposed along a line parallel to said first direction.

13. The alignment tool of claim 12 further comprising a third distance sensor positioned to measure the distance of a third location of said reference surface from said third sensor and to measure the distance of a third location of said target from said third sensor.

14. The alignment tool of claim 13 wherein said system has a mechanism for adjusting the orientation of said robot blade along a second direction, wherein said second and third sensors are disposed along a line parallel to said second direction.

15. An alignment tool for aligning a robot blade carrying a workpiece in a robot chamber of a workpiece handling system, and a base plane defined by a floor surface of said chamber of said system, comprising:

a frame adapted to be supported by said floor surface, said frame having a plurality of legs adapted to engage said floor surface to support said frame above said floor surface; and

a distance sensor attached to said frame and positioned to measure the distance of a target carried by said robot blade in said chamber, from said sensor.

16. An alignment tool for aligning a robot blade carrying a workpiece in a chamber of a workpiece handling system, and a base plane defined by a support surface of said system, comprising:

a frame adapted to be supported by said system support surface; and

a plurality of non-contact distance sensors positioned within said frame to measure the tilt orientation of a target carried by said robot blade relative to a reference plane within said frame.

20. The tool of claim 16 wherein said plurality of distance sensors are positioned to measure the distances of a plurality of locations on a target carried by said robot blade relative to said reference plane.

21. The tool of claim 20 wherein each of said sensors comprises a laser distance sensor carried by said frame and positioned to measure one of said distances of said plurality of locations on said target carried by said robot blade relative to said reference plane.

22. The tool of claim 20 further comprising a display for displaying a numerical representation of each of said measured distances of said plurality of locations on said target carried by said robot blade relative to said reference plane.

23. The tool of claim 16 further comprising a display for displaying at least one of a numerical representation and a graphical representation of said measured orientation of said reference plane relative to said target carried by said robot blade.

24. The tool of claim 20 further comprising a calculator for calculating a difference between selected measured distances of selected locations of said plurality of locations on said target carried by said robot blade relative to said reference plane.

25. The tool of claim 24 further comprising a display for displaying a numerical representation of said calculated difference between selected measured distances of selected locations of said plurality of locations on said target carried by said robot blade relative to said reference plane.

27. The alignment tool of claim 25 wherein said system platform includes a chamber having a floor and wherein said frame means base has means for positioning said base on said floor of said chamber.

28. The alignment tool of claim 22 wherein said base plane is defined by said chamber floor.

29. The alignment tool of claim 27 wherein said base positioning means includes a plurality of legs adapted to rest on said floor.

17. An alignment tool for aligning a robot blade carrying a workpiece in a chamber of a workpiece handling system, and a base plane defined by a support surface of said system, comprising:

a frame adapted to be supported by said system support surface; and

a plurality of non-contact distance sensors positioned within said frame to measure the orientation of a target carried by said robot blade relative to a reference plane within said frame wherein said system has a chamber which has a floor which defines a base plane and said frame has a reference surface which defines said reference plane at a predetermined height above said base plane.

18. The tool of claim 17 wherein said reference plane is substantially parallel to said base plane.

19. The tool of claim 18 wherein said reference surface includes three separate and coplanar subsurfaces.

26. An alignment tool for aligning a robot blade carrying a workpiece in a workpiece handling system, with respect to a base plane defined by a platform of said system, comprising:

means for measuring the orientation of a target carried by said robot blade relative to said base plane, said measuring means including a plurality of distance sensor means for measuring the distances between said target and each of said sensor means, and frame means having a base, for mounting said sensor means and supporting said sensor means above said platform of said system, said frame means having opening means for admitting a target carried by said robot blade between said sensor means and said base.

30. The alignment tool of claim 26 herein said frame means includes reference surface means for providing a reference plane parallel to and a predetermined distance above said base plane;

and said measuring means includes means for measuring the orientation of said target carried by said robot blade relative to said reference plane.

31. The alignment tool of claim 26 herein said sensor means includes laser means for emitting a laser beam and detector means for detecting a laser beam.

32. The alignment tool of claim 30 wherein a first sensor means includes means for measuring the distance of a first location of said reference surface from said first sensor means and measuring the distance of a first location of said target from said first sensor means;

a second sensor means includes means for measuring the distance of a second location of said reference surface from said second sensor means and measuring the distance of a second location of said target from said second sensor means; and

a third sensor means includes means for measuring the distance of a third location of said reference surface from said third sensor means and measuring the distance of a third location of said target from said third sensor means.

33. The alignment tool of claim 32 further comprising display means for displaying a numerical representation of each of said measured distances of said plurality of locations on said target carried by said robot blade relative to said reference surface.

34. The alignment tool of claim 26 further comprising display means for displaying at least one of a numerical representation and a graphical representation of said measured orientation of said target carried by said robot blade relative to said base plane.

35. The alignment tool of claim 32 further comprising calculating means for calculating a difference between selected measured distances of selected locations of said plurality of locations on said target carried by aid robot blade relative to said reference surface.

36. The alignment tool of claim 35 further comprising display means for displaying a numerical representation of said calculated difference between selected measured distances of selected locations of said plurality of locations on said target carried by said robot blade relative to said reference surface.

37. An alignment tool for aligning a robot blade carrying a target wafer in a transfer chamber, and a base plane defined by a floor of said transfer chamber, comprising:

a frame having a plurality of legs adapted to be supported by said floor of said transfer chamber, said frame further having a first plate which defines at least three triangularly spaced, coplanar reference surfaces, said frame further having at least three triangularly spaced sensor mountings, a second plate carrying said sensor mountings, and a plurality of brackets spacing said first plate and said second plate; and

at least three laser distance measuring sensors, each sensor being mounted to a sensor mounting and positioned facing a reference surface on said first plate;

wherein said frame defines an opening positioned between said reference surfaces and said sensors, said opening being sized sufficiently to admit a target wafer carried by said robot blade between said sensors and said reference surfaces and wherein said sensors are positioned by said sensor mountings to measure the orientation of said target wafer carried by said robot blade relative to said coplanar reference surfaces.