Low-inertia multi-axis multi-directional mechanically scanned ion implantation system

• US 8,227,768 B2
• Filed: 06/18/2009
• Issued: 07/24/2012
• Est. Priority Date: 06/25/2008
• Status: Expired due to Fees

• Current Assignee: Axcelis Technologies Incorporated
• Original Assignee: Axcelis Technologies Incorporated
• Inventors: Smick, Theodore, Ryding, Geoffrey, Horner, Ronald F., Eide, Paul, Farley, Marvin, Ota, Kan
• Primary Examiner(s): Vanore, David A
• Assistant Examiner(s): IPPOLITO, NICOLE MARIE
• Application Number:
  US12/487,229
• Publication Number:
  US 20090321631A1
• Time in Patent Office: 1,132 Days
• Field of Search: 250/491.1, 250/492.1, 250/492.22, 250/492.3
• US Class Current: 250/491.1
• CPC Class Codes: F16M 11/123 the axis of rotation intersecting in a single point, e.g. by using gimbals
• CPC Class Codes: F16M 11/18 with mechanism for moving the apparatus relatively to the stand
• CPC Class Codes: H01J 2237/20 Positioning, supporting, modifying or maintaining the physical state of objects being observed or treated
• CPC Class Codes: H01J 2237/2007 Holding mechanisms
• CPC Class Codes: H01J 2237/202 Movement
• CPC Class Codes: H01J 2237/20278 Motorised movement
• CPC Class Codes: H01J 37/20 Means for supporting or positioning the objects or the material; Means for adjusting diaphragms or lenses associated with the support introducing the objects H01J37/18
• CPC Class Codes: H01J 37/3171 for ion implantation plasma immersion ion implantation H01J37/32412

Abstract

An ion implantation system configured to produce an ion beam is provided, wherein an end station has a robotic architecture having at least four degrees of freedom. An end effector operatively coupled to the robotic architecture selectively grips and translates a workpiece through the ion beam. The robotic architecture has a plurality of motors operatively coupled to the end station, each having a rotational shaft. At least a portion of each rotational shaft generally resides within the end station, and each of the plurality of motors has a linkage assembly respectively associated therewith, wherein each linkage assembly respectively has a crank arm and a strut. The crank arm of each linkage assembly is fixedly coupled to the respective rotational shaft, and the strut of each linkage assembly is pivotally coupled to the respective crank arm at a first joint, and pivotally coupled to the end effector at a second joint.

Claims

1. An ion implantation system, comprising:

an ion source configured to form an ion beam;

a mass analyzer configured to mass analyze the ion beam;

an end station, wherein the end station comprises a robotic architecture having at least four degrees of freedom;

one or more electrostatic chucks configured to selectively grip a workpiece; and

an end effector operatively coupled to the robotic architecture, wherein the end effector comprises a central structure configured to selectively engage and disengage each of the one or more electrostatic chucks, and wherein the robotic architecture is configured to selectively translate the workpiece through the ion beam.

2. The ion implantation system of claim 1, wherein the robotic architecture comprises a modified Stewart platform.

3. The ion implantation system of claim 1, wherein the robotic architecture comprises a modified delta robot.

4. The ion implantation system of claim 1, wherein the robotic architecture comprises:

a plurality of motors operatively coupled to the end station, wherein each of the plurality of motors has a rotational shaft associated therewith, wherein at least a portion of each rotational shaft generally resides within the end station, and wherein each of the plurality of motors has a linkage assembly respectively associated therewith, wherein each linkage assembly respectively comprises a crank arm and a strut, wherein the crank arm of each linkage assembly is fixedly coupled to the respective rotational shaft, and wherein the strut of each linkage assembly is pivotally coupled to the respective crank arm at a first joint, and pivotally coupled to the end effector at a second joint.

5. The ion implantation system of claim 4, wherein the plurality of motors is comprised of six servo motors operatively coupled to six linkage assemblies, therein providing six degrees of freedom of movement of the end effector.

6. The ion implantation system of claim 5, wherein the end effector comprises three pivot points, wherein two struts are pivotally coupled to each pivot point.

7. The ion implantation system of claim 6, wherein the end effector comprises three spokes emanating from a central structure, and wherein the three pivot points are generally defined at an end of each spoke.

8. The ion implantation system of claim 7, wherein two of the three spokes are generally perpendicular to one another.

9. The ion implantation system of claim 8, further comprising two long-slit faradays, wherein the two long-slit faradays are respectively coupled to the two of the three spokes that are generally perpendicular to one another.

10. The ion implantation system of claim 6, wherein the end effector comprises:

a plurality of spokes emanating from a central structure; and

an arcuate structure generally surrounding the central structure, wherein the three pivot points are generally defined along the arcuate structure, wherein the arcuate structure generally increases a stiffness of the end effector.

11. The ion implantation system of claim 10, wherein the arcuate structure comprises an enclosed ring.

12. The ion implantation system of claim 10, wherein the plurality of spokes is comprised of three spokes, wherein two of the three spokes are generally perpendicular to one another.

13. The ion implantation system of claim 12, further comprising two long-slit faradays, wherein the two long-slit faradays are respectively coupled to the two of the three spokes that are generally perpendicular to one another.

14. The ion implantation system of claim 4, wherein the end station is substantially sealed from an external environment, and wherein the plurality of motors fully reside within the end station.

15. The ion implantation system of claim 14, wherein the plurality of motors comprise high vacuum motors having integral cooling and vacuum seals.

16. The ion implantation system of claim 4, wherein the plurality of motors comprise a respective plurality of encoders, wherein a control of the plurality of motors is based on feedback from the plurality of encoders.

17. The ion implantation system of claim 1, further comprising an electrostatic chuck base station, wherein the one more electrostatic chucks are configured to be heated and/or cooled at the electrostatic chuck base station, and wherein the central structure is configured to selectively engage and disengage each of the electrostatic chucks at the electrostatic chuck base station.

18. The ion implantation system of claim 1, wherein the central structure further comprises a pivot apparatus, wherein the pivot apparatus is configured to selectively rotate the one or more electrostatic chucks in one or more axes.

19. The ion implantation system of claim 18, wherein the three pivot points generally defines a plane of the central structure, and wherein the pivot apparatus is configured to rotate the one or more electrostatic chucks along an axis that is generally parallel to the plane of the central structure.

20. The ion implantation system of claim 18, wherein the three pivot points generally defines a plane of the central structure, and wherein the pivot apparatus is configured to rotate the one or more electrostatic chucks along an axis that is generally perpendicular to the plane of the central structure.

21. The ion implantation system of claim 18, wherein the pivot apparatus is configured to rotate the one or more electrostatic chucks along one or more axes with respect to the central structure.

22. The ion implantation system of claim 1, wherein the end station further comprises a generally hollow cylindrical beam dump positioned along a path of the ion beam generally downstream of the workpiece, wherein the beam dump is configured to generally confine particulate contamination to within the beam dump.

23. The ion implantation system of claim 22, wherein the beam dump comprises a cylindrical faraday.

24. The ion implantation system of claim 22, wherein an interior surface of the beam dump is comprised of graphite.

25. The ion implantation system of claim 1, further comprising a controller configured to control the robotic architecture, wherein the workpiece is scanned through the ion beam in a predetermined manner.

26. A workpiece scanning system for scanning a workpiece through an ion beam, the workpiece scanning system comprising:

a process chamber associated with the ion beam;

a plurality of motors operably coupled to the process chamber, wherein each of the plurality of motors has a rotational shaft associated therewith, wherein at least a portion of each rotational shaft generally resides within the process chamber;

a linkage assembly associated with each of the plurality of motors, wherein each linkage assembly respectively comprises a crank arm fixedly coupled to the at least a portion of the rotational shaft and a strut pivotally coupled to the crank arm;

an end effector operably coupled to the strut of each linkage assembly;

a plurality of electrostatic chucks, wherein each of the plurality of electrostatic chucks is operable to support the workpiece thereon;

an electrostatic chuck base station, wherein the end effector comprises a central structure configured to selectively engage and disengage each of the plurality of electrostatic chucks from the electrostatic chuck base station, and

a controller operable to control the position of the workpiece with respect to the ion beam via a control of the plurality of motors.

27. The workpiece scanning system of claim 26, wherein the plurality of electrostatic chucks are configured to be heated and/or cooled at the electrostatic chuck base station.

28. The workpiece scanning system of claim 26, wherein the electrostatic chuck base station is configured to selectively heat or cool each of the plurality of electrostatic chucks.

29. A method for implanting ions into a workpiece, the method comprising:

providing an ion beam;

providing a workpiece scanning system comprising a plurality of motors operatively coupled to an end station, wherein each of the plurality of motors has a rotational shaft associated therewith, wherein at least a portion of each rotational shaft generally resides within the end station, and wherein each of the plurality of motors has a linkage assembly respectively associated therewith, wherein each linkage assembly respectively comprises a crank arm and a strut, wherein the crank arm of each linkage assembly is fixedly coupled to the respective rotational shaft, and wherein the strut of each linkage assembly is pivotally coupled to the respective crank arm at a first joint, and wherein each strut is further pivotally coupled to an end effector at a second joint;

providing a plurality of electrostatic chucks, wherein each of the plurality of electrostatic chucks are operable to selectively grip the workpiece, and wherein the end effector comprises a central structure associated with the plurality of electrostatic chucks;

selectively engaging one of the plurality electrostatic chucks via the central structure;

selectively engaging the workpiece via the one of the plurality of electrostatic chucks;

gripping the workpiece via the end effector; and

controlling a spatial position and orientation of the end effector and workpiece with respect to the ion beam via a control of the plurality of motors, wherein the workpiece is scanned through the ion beam along a predetermined scan path.

30. The method of claim 29, wherein the predetermined scan path comprises a plurality of generally polygonal scans of the ion beam when viewed from the plane of the workpiece.

31. The method of claim 29, wherein the predetermined scan path comprises a plurality of generally octagonal scans of the ion beam when viewed from the plane of the workpiece.

32. The method of claim 29, wherein the predetermined scan path comprises one or more of a plurality of vector, raster, arcuate, and circular scans of the ion beam when viewed from the plane of the workpiece.

33. The method of claim 29, wherein the plurality of motors comprise a respective plurality of encoders, wherein the control of the plurality of motors is based on feedback from the plurality of encoders.

34. The method of claim 29, further comprising heating and/or cooling the plurality of electrostatic chucks at an electrostatic chuck base station, wherein the central structure is configured to selectively engage and disengage one of the plurality of electrostatic chucks at the electrostatic chuck base station based on one or more of a desired processing temperature and a condition of each of the plurality of electrostatic chucks.

35. The method of claim 34, wherein the condition of each of the plurality of electrostatic chucks comprises a temperature of each of the plurality of electrostatic chucks.