Substrate transport apparatus with automated alignment

• US 20070065144A1
• Filed: 07/11/2006
• Published: 03/22/2007
• Est. Priority Date: 07/11/2005
• Status: Active Grant

• Current Assignee: Brooks Automation Ltd. (United Kingdom) (Azenta, Inc.)
• Original Assignee: Brooks Automation Incorporated (Azenta, Inc.)
• Inventors: Beale, Stuart, Hofmeister, Christopher, Hosek, Martin
• Granted Patent: US 7,522,267 B2
• Time in Patent Office: Days
• US Class Current: 396/611
• CPC Class Codes: H01L 21/67259 Position monitoring, e.g. misposition detection or presence detection
• CPC Class Codes: H01L 21/68 for positioning, orientation or alignment
• CPC Class Codes: H01L 21/681 using optical controlling means
• CPC Class Codes: H01L 21/68707 the wafers being placed on a robot blade, or gripped by a gripper for conveyance

Abstract

A substrate processing apparatus is provided with a substrate transport apparatus. The transport apparatus is used for automating alignment of the processing apparatus. In one aspect, a through-beam sensor on the transport apparatus is used to level parts of the processing apparatus. In another aspect, a through-beam sensor on the transport apparatus is used to determine the locations and angular orientations of substrate stations within a plane. In another aspect, the transport apparatus teaches itself the accurate location of a substrate aligner by repeatedly placing the substrate on the aligner, recording positional data, constructing a cost function, and determining the location of the aligner by minimizing the cost function using a numerical technique.

Claims

1. A substrate processing apparatus comprising:

a frame forming a substrate station surface on which a substrate can be seated; and

a leveling device connected to the frame for leveling the substrate station surface relative to a predetermined reference frame;

wherein the leveling device comprises a drive system connected to the frame, a movable arm connected to the drive system and having a movable through-beam sensor thereon, and a control system connected to the drive system for moving the through-beam sensor and positioning the through-beam sensor relative to the substrate station surface; and

wherein the control system is programmed to position the through-beam sensor for detecting at least one predetermined geometric feature connected to the substrate station surface so that detection of the predetermined geometric feature with the through-beam sensor is capable of defining, in the control system, an inclination of the substrate station surface relative to the reference frame.

2. The apparatus of claim 1, wherein the control system is further programmed to determine a vertical position of the substrate station surface.

3. The apparatus of claim 1 wherein the substrate processing apparatus further comprises a leveling system connected to the frame for changing an orientation of the substrate station surface relative to the predetermined reference frame, and wherein the control system is further programmed to generate a leveling input for adjusting the leveling system to change the orientation of the substrate station surface relative to the predetermined reference frame.

4. The apparatus of claim 3 wherein the leveling input is optimized to minimize the total required adjustment.

5. The apparatus of claim 3 wherein the leveling input is generated to place the substrate station surface at a desired height.

6. The apparatus of claim 1 wherein the control system is further programmed to determine the position of the substrate station along a direction that is perpendicular to a plane within which the movable arm is operable to rotate.

7. The apparatus of claim 1 wherein the leveling device is operable to transport a substrate.

8. An apparatus for determining the inclination of a substrate station relative to a reference plane, the apparatus comprising:

a drive system;

a movable arm connected to the drive system and having a positionable through-beam sensor; and

a control system controllably connected to the drive system for moving the movable arm and positioning the through-beam sensor at predetermined positions;

wherein the control system is adapted for positioning the through-beam sensor with the drive system to serially approach and detect at least three reference features, the reference features having a predetermined geometrical relationship to the substrate station; and

wherein the control system is further adapted to record a position of the sensor when each reference feature is detected; and

wherein the control system is programmed to calculate an inclination of the substrate station relative to the reference plane along at least two directions within the reference plane.

9. The apparatus of claim 8, wherein the control system is further programmed to determine the position of the substrate station along a direction that is perpendicular to the reference plane.

10. The apparatus of claim 8 wherein the movable arm comprises at least two rigid members and a joint, the joint being disposed between the two members for rotation of at least one of the two members about a single axis that is perpendicular to the reference plane.

11. The apparatus of claim 10 wherein the control system is further programmed to determine the position of the substrate station along the direction of the single axis.

12. The apparatus of claim 8 wherein the apparatus is operable to transport a substrate.

13. The apparatus of claim 8 wherein the control system is further programmed for determining adjustments to adjustment features for leveling a substrate holder, the substrate holder being adapted to hold a substrate at the substrate station.

14. The apparatus of claim 13 wherein the adjustments are optimized to minimize the total required adjustment.

15. The apparatus of claim 13 wherein the adjustments are also determined so as to place the substrate holder at a desired height.

16. The apparatus of claim 8 wherein the control system is adapted for moving the through-beam sensor, when positioning the through-beam sensor to detect a reference feature, in a predetermined direction having a predetermined orientation relative to the reference plane.

17. The apparatus of claim 16 wherein the predetermined orientation is substantially horizontal.

18. The apparatus of claim 8 wherein the recorded position has a predetermined relationship to the reference plane.

19. A substrate transport apparatus auto-teach system comprising:

a frame forming a substrate station surface on which a substrate can be seated;

a drive system connected to the frame and associated with a transport apparatus coordinate system;

a movable arm connected to the drive system and having a positionable through-beam sensor; and

a control system controllably connected to the drive system for moving the movable arm and positioning the through-beam sensor;

wherein the control system is programmed for positioning the through-beam sensor for detecting at least one reference feature connected to the substrate station surface along at least three different substantially co-planar paths of approach, the at least one reference feature having a predetermined geometric relationship to the substrate station surface;

wherein the control system is further programmed to record the position of the sensor when the at least one reference feature is detected on each path of approach, and to determine therefrom the location of the substrate station surface in the transport apparatus coordinate system and an angular orientation of the substrate station surface.

20. The substrate transport apparatus auto-teach system of claim 19 wherein each of the at least three paths of approach is defined by a segment of a different line, and wherein at least three of the lines intersect at a common point.

21. The substrate transport apparatus auto-teach system of claim 19 wherein the control system is programmed to approach one of the reference features along at least two different paths of approach.

22. The substrate transport apparatus auto-teach system of claim 19 wherein the determined angular orientation of the substrate station surface is an angular orientation within a plane defined by the surface.

23. The substrate transport apparatus auto-teach system of claim 19 wherein the paths of approach are each substantially horizontal.

24. The substrate transport apparatus auto-teach system of claim 19 wherein the movable arm is a scara arm.

25. The substrate transport apparatus auto-teach system of claim 19 wherein the substrate station surface is located on or within at least one of a transport container, an aligner, a buffer station, a load lock, a load port, a processing station, or a metrology station.

26. A substrate processing apparatus comprising the substrate transport apparatus auto-teach system of claim 19.

27. A substrate transport apparatus auto-teach system comprising:

a frame defining a substrate station surface capable of supporting a substrate;

a substrate transport apparatus that is movably connected to the frame, the substrate transport apparatus having an associated transport apparatus coordinate system;

an aligner connected to the frame; and

a control system operably connected to the substrate transport apparatus and programmed to position with the substrate transport apparatus, an object on the aligner, and to measure with the aligner a spatial relationship between the object and the aligner;

wherein the control system is programmed to determine coordinates for a the substrate station surface, in the transport apparatus coordinate system, based on the measured spatial relationship.

28. The system in claim 27, wherein the object has a predetermined positional relationship with respect to the substrate station surface.

29. The system in claim 27, wherein the object is a substrate.

30. The system in claim 27, wherein the control system is further programmed to pick the substrate from the substrate station surface prior to positioning the object on the aligner.

31. The system in claim 30, wherein the control system has a model representation of the substrate station surface locating the substrate station with respect to a reference frame of the model representation.

32. The system of claim 27 wherein the control system is further programmed to determine an angular orientation of the substrate station.

33. A substrate transport apparatus auto-teach system for auto-teaching a location to a substrate transport apparatus, the system comprising:

a frame, the substrate transport apparatus being movably connected to the frame and having an associated transport apparatus coordinate system;

a substrate aligner connected to the frame; and

a control system operably connected to the substrate transport apparatus and to the substrate aligner, the control system being programmed to position with the substrate transport apparatus, an object on the substrate aligner, and to measure with the substrate aligner a spatial relationship between the object and the substrate aligner; and

wherein the control system is programmed to determine coordinates of the substrate aligner in the transport apparatus coordinate system based on the measured spatial relationship.

34. The system in claim 33, wherein the control system determines the coordinates of the substrate aligner by generating a cost function and analyzing the cost function using a numerical method.

35. A method of leveling an object relative to a predetermined reference frame, which comprises:

approaching and detecting the at least one feature at least twice with a through-beam sensor mounted on a robotic arm, the at least one feature having a predetermined geometric relationship to the object, and the object having a substrate support surface capable of supporting a substrate; and

determining, with a control system connected to the robotic arm, an inclination of the object relative to the predetermined reference frame.

36. The method of claim 35 further comprising generating, with the control system, a leveling input for changing an inclination of the object relative to the predetermined reference frame and leveling the substrate support surface relative to the predetermined reference frame by using the leveling input.

37. The method of claim 35 wherein the robotic arm is a scara arm.

38. The method of claim 35 wherein the at least one feature comprises three features, and wherein each of the three features is approached at least once with the through-beam sensor.

39. A method comprising:

approaching and detecting at least one reference feature having a predetermined geometric relationship with an object at least three times with a through-beam sensor mounted on a robotic arm, the robotic arm being controlled by a control system; and

determining, with the control system, a location of the object in at least two degrees of freedom relative to a predetermined reference frame, and determining an angular orientation of the of the object, the location and angular orientation being determined from the detection of the reference features.

40. The method of claim 39 wherein the at least one reference feature comprises at least two reference features.

41. The method of claim 39 wherein the object comprises a substrate support for removably supporting a substrate.

42. The method of claim 39 wherein the robotic arm is a scara arm.

43. A method of determining a location of a substrate aligner relative to a predetermined reference frame, which comprises:

providing a control system;

providing a substrate transport apparatus communicably connected to the control system;

providing a substrate aligner communicably connected to the control system;

placing an object on the substrate aligner with the substrate transport apparatus, to generate positional data relating a substrate aligner location to one or more locations of placement of the object on the substrate aligner; and

analyzing the positional data with the control system to determine the location of the substrate aligner relative to a predetermined reference frame.

44. The method of claim 43 wherein the object is placed on the substrate aligner more than once, and wherein no pair of the locations of placement of the object are located more than about five millimeters apart.

45. The method of claim 43 wherein analyzing the positional data comprises generating a cost function with the control system and using the control system to find an extreme of the cost function with a numerical technique.