Ion implantation system for implanting workpieces

• US 5,793,050 A
• Filed: 11/26/1996
• Issued: 08/11/1998
• Est. Priority Date: 02/16/1996
• Status: Expired due to Fees

• Current Assignee: Axcelis Technologies Incorporated
• Original Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Inventors: Rose, Peter H., Blake, Julian G., McRay, Richard F., Hughey, Barbara J., Brailove, Adam A., Yang, Zhongmin
• Primary Examiner(s): NGUYEN, KIET TUAN
• Application Number:
  US08/756,133
• Time in Patent Office: 623 Days
• Field of Search: 250/492.21, 250/492.2, 250/492.1, 250/441.11, 250/442.11, 414/217, 414/222, 414/225, 414/220, 414/221
• US Class Current: 250/492.21
• CPC Class Codes: H01J 2237/022 Avoiding or removing foreign or contaminating particles, debris or deposits on sample or tube
• CPC Class Codes: H01J 2237/083 Beam forming
• CPC Class Codes: H01J 2237/184 Vacuum locks
• CPC Class Codes: H01J 2237/2001 Maintaining constant desired temperature
• CPC Class Codes: H01J 2237/2007 Holding mechanisms
• CPC Class Codes: H01J 2237/20228 Mechanical X-Y scanning
• CPC Class Codes: H01J 2237/204 Means for introducing and/or outputting objects
• CPC Class Codes: H01J 2237/31701 Ion implantation
• CPC Class Codes: H01J 2237/31705 Impurity or contaminant control
• CPC Class Codes: H01J 27/14 Other arc discharge ion sources using an applied magnetic field
• CPC Class Codes: H01J 37/08 Ion sources; Ion guns
• CPC Class Codes: H01J 37/18 Vacuum locks ; Means for obtaining or maintaining the desired pressure within the vessel
• CPC Class Codes: H01J 37/3002 Details
• CPC Class Codes: H01J 37/3007 Electron or ion-optical systems
• CPC Class Codes: H01J 37/304 Controlling tubes by information coming from the objects or from the beam, e.g. correction signals
• CPC Class Codes: H01J 37/3171 for ion implantation
• CPC Class Codes: H01L 21/67069 for drying etching
• CPC Class Codes: H01L 21/67109 mainly by convection
• CPC Class Codes: H01L 21/67745 characterized by movements or sequence of movements of transfer devices
• CPC Class Codes: H01L 21/67748 horizontal transfer of a single workpiece
• CPC Class Codes: H01L 21/67751 : vertical transfer of a single workpiece
• CPC Class Codes: H01L 21/67778 : involving loading and unloading of wafers
• CPC Class Codes: H01L 21/6838 : with gripping and holding devices using a vacuum; Bernoulli devices

Abstract

An ion implantation system that rapidly and efficiently processes large quantities of workpieces, such as flat panel displays. The ion implantation system includes a high vacuum process chamber that mounts an ion source, a single workpiece translating stage, and a loadlock. The single workpiece handling assembly mounted within the process chamber both removes the workpiece from the loadlock and supports the workpiece during implantation by the ion beam generated by the ion source. The process chamber is in selective fluid communication with a loadlock assembly, which in turn is mechanically integrated with a workpiece loading or end station. Additionally, the workpiece handling assembly includes a translation stage or element for translating the workpiece in a linear scanning direction during implantation. This linear scanning direction extends along a path transverse or orthogonal to the horizontal longitudinal axis of the implantation system. According to one practice, the scanning direction and the longitudinal axis form an angle therebetween that is less than or equal to about 85 degrees.

Claims

1. An ion implantation system for processing a workpiece, comprising

an ion source for ionizing selected matter to generate an ion beam,

a housing defining a process chamber that is fluidly coupled to the ion source,

a loadlock chamber coupled to the housing and separately pressurizable relative to the process chamber, and

a single workpiece handling assembly mounted within the process chamber for removing the workpiece from the loadlock chamber and for supporting the workpiece during implantation by the ion beam generated by the ion source.

2. The ion implantation system of claim 1, wherein the workpiece handling assembly includes translation means for translating the workpiece in a linear translating direction during implantation.

3. The ion implantation system of claim 2, wherein the ion implantation system extends along a longitudinal axis, and wherein the ion beam generated by the ion source is directed transverse to the longitudinal axis.

4. The ion implantation system of claim 3, wherein the translation means translates the workpiece through the ion beam in the translating direction which is disposed generally orthogonal to the ion beam.

5. The ion implantation system of claim 3, wherein the ion beam generated by the ion source and the longitudinal axis form an angle therebetween that is greater than or equal to about 85 degrees.

6. The ion implantation system of claim 1, wherein the system extends along a longitudinal axis, and wherein the ion beam generated by the ion source and the longitudinal axis form an angle therebetween of equal to or greater than about 5 degrees.

7. The ion implantation system of claim 1, wherein the workpiece handling assembly includes a platen for supporting the workpiece during processing, and means for moving the position of the platen relative to the loadlock chamber.

8. The ion implantation system of claim 1, further comprising an end station assembly having a workpiece cassette for storing a plurality of workpieces, and an end effector for transporting the workpieces between the cassette and the loadlock chamber.

9. The ion implantation system of claim 1, further including a controller for controlling automatically movement of the workpiece handling assembly.

10. The ion implantation system of claim 1, wherein the ion source includes means for generating a ribbon beam.

11. The ion implantation system of claim 1, further comprising pressure means coupled to the loadlock chamber for disposing the loadlock chamber at a selected pressure.

12. The ion implantation system of claim 1, further comprising temperature control means coupled to the loadlock chamber for disposing at least a portion thereof at a selected temperature.

13. The ion implantation system of claim 1, further including cooling structure for disposing a floor of the loadlock chamber at a selected temperature to form a cold deck.

14. The ion implantation system of claim 1, further including vacuum means coupled to a cooling surface of the loadlock for drawing the workpiece into contact therewith when the workpiece is disposed within the chamber, thereby effecting heat transfer from the workpiece to the cooling surface.

15. The ion implantation system of claim 14, wherein the cooling surface has a plurality of vacuum-applying openings formed therein, the openings being in fluid communication with the vacuum means for disposing a substantial portion of the backside of the workpiece in contact with the cooling surface.

16. The ion implantation system of claim 14, further comprising means for circulating a cooling fluid through the chamber floor to form a cooling surface.

17. The ion implantation system of claim 14, wherein the vacuum means includes a fluid network formed in the cooling surface for applying a pressure to the backside of the workpiece.

18. The ion implantation system of claim 1, further comprising a plurality of loadlock stack elements each having a top surface and a bottom surface, the loadlock elements being axially positioned relative to each other to form a stacked array of loadlocks.

19. The ion implantation system of claim 18, wherein each loadlock stack element includes nesting means for nesting one of the loadlock elements with an adjacent loadlock element when stacked together.

20. The ion implantation system of claim 19, wherein the nesting means further comprises a configured bottom surface having a first geometric shape that nests with a configured top surface of an adjacent loadlock having a complementary geometric shape such that the loadlocks nest together when stacked.

21. The ion implantation system of claim 20, wherein the bottom surface of each loadlock has a first bottom-most side, an outwardly stepped second bottom side, and a further outwardly stepped third bottom side.

22. The ion implantation system of claim 20, wherein the top surface of each loadlock has a first topmost face, a recessed second face which is separated from the first face by a first wall portion, and a further recessed third top face.

23. The ion implantation system of claim 18, wherein the stacked array of loadlocks are configured to facilitate processing of multiple workpieces by the ion implantation system.

24. The ion implantation system of claim 1, further comprising a gate valve operatively coupled with a front slot formed in a front portion of the loadlock, and a second gate valve operatively coupled with a rear slot formed opposite the front opening in a rear portion of the loadlock and being disposed in registration with the front slot to allow passage of the workpiece therethrough.

25. An ion implantation system extending along a horizontal axis for processing a workpiece, comprising

an ion source for ionizing selected matter to generate an ion beam,

a housing defining a process chamber that is fluidly coupled to the ion source,

a loadlock coupled to the housing and separately pressurizable relative to the process chamber, and

a workpiece handling assembly mounted within the process chamber for holding the workpiece during implantation by the ion beam generated by the ion source, wherein the handling assembly translates the workpiece in a linear translating direction transverse to the horizontal axis during processing.

26. The ion implantation system of claim 25, wherein the linear translation direction and the horizontal axis define an angle therebetween equal to or less than about 85 degrees.

27. The ion implantation system of claim 25, wherein the ion beam generated by the ion source is directed in a direction transverse to the horizontal axis to form an angle therebetween greater than or equal to about 5 degrees.

28. The ion implantation system of claim 25, wherein said workpiece handling assembly further comprises a single workpiece transfer assembly for moving a workpiece between the loadlock and the process chamber and for holding the workpiece during processing.

29. The ion implantation system of claim 25, wherein the workpiece handling assembly includes a platen for supporting the workpiece during processing, and means for moving the position of the platen.

30. The ion implantation system of claim 25, further comprising an end station assembly having a workpiece cassette for storing a plurality of workpieces, and an end effector for transporting the workpieces between the cassette and the loadlock.

31. The ion implantation system of claim 25, wherein the ion source includes means for generating a ribbon beam.

32. The ion implantation system of claim 25, further comprising a plurality of loadlocks each having a top surface and a bottom surface, the loadlocks being axially positioned relative to each other to form a stacked array of loadlocks.

33. The ion implantation system of claim 32, wherein each loadlock includes means for nesting the loadlocks with an adjacent loadlock when stacked together.

34. The ion implantation system of claim 32, wherein the stacked array of loadlocks are configured to facilitate processing of multiple workpieces by the ion implantation system.