Processing thin wafers

• US 7,611,322 B2
• Filed: 08/31/2005
• Issued: 11/03/2009
• Est. Priority Date: 11/18/2004
• Status: Active Grant

• Current Assignee: Intevac
• Original Assignee: Intevac
• Inventors: Scollay, Stuart, Tong, Edric, Bluck, Terry
• Primary Examiner(s): MOORE, KARLA A
• Application Number:
  US11/218,085
• Publication Number:
  US 20060102285A1
• Time in Patent Office: 1,525 Days
• Field of Search: 414217-2265, 414/589, 414/781, 414805-806, 414935-941, 15634531-34532, 118/719, 118/733
• US Class Current: 414/805
• CPC Class Codes: H01L 21/67161 characterized by the layout of the process chambers
• CPC Class Codes: H01L 21/67173 in-line arrangement
• CPC Class Codes: H01L 21/6719 characterized by the construction of the processing chambers, e.g. modular processing chambers
• CPC Class Codes: H01L 21/67201 characterized by the construction of the load-lock chamber
• CPC Class Codes: H01L 21/67745 characterized by movements or sequence of movements of transfer devices
• CPC Class Codes: H01L 21/67751 vertical transfer of a single workpiece
• CPC Class Codes: H01L 21/6831 using electrostatic chucks
• CPC Class Codes: Y10S 414/135 Associated with semiconductor wafer handling
• CPC Class Codes: Y10S 414/136 including wafer orienting means
• CPC Class Codes: Y10S 414/139 including wafer charging or discharging means for vacuum chamber
• CPC Class Codes: Y10S 414/141 includes means for gripping wafer

Abstract

There is described a wafer processing system for thinned wafers that are easily broken during handling. The system protects against breakage during handling and provides for temperature controls during processing.

Claims

1. The method of transferring a silicon wafer with a thinned back surface from a robotic arm into processing stations comprising moving said thinned back surface wafer on the robotic arm into a load lock chamber, elevating said wafer from said arm to a non-contact chuck within said load lock chamber using negative and positive pressure gas applied through said non-contact chuck, said wafer being raised close to but maintained out of contact with said non-contact chuck, removing said robotic arm from said load lock chamber, lowering said wafer to an electrostatic chuck positioned in said load lock chamber below said non-contact chuck using gas flow through said non-contact chuck and through said electrostatic chuck to bring said wafer close to but not into contact with said electrostatic chuck, sealing and drawing a vacuum in said load lock chamber, striking a plasma in said load lock chamber as to bind said wafer to said electrostatic chuck, and then under vacuum conditions moving said electrostatic chuck carrying said wafer out of said load lock chamber for processing of said wafer in follow-on semiconductor processing chambers.

2. The method of claim 1 including preventing said wafer from skating along a surface of said non-contact chuck when said wafer is close to but out of contact with said non-contact chuck by positioning arms along the circumference of said non-contact chuck to maintain said wafer centrally positioned over said non-contact chuck.

3. The method of claim 2 including placing said electrostatic chuck into a carrier in said load lock prior to the application of a plasma to bind said wafer to said electrostatic chuck.

4. The method of claim 3 including moving said wafer in said carrier from said load lock into said follow-on semiconductor processing chambers.

5. The method of claim 3 including cooling said wafer while in said load lock chamber by applying a cooling gas to said wafer while in position along a face of said electrostatic chuck.

6. The method of claim 5 including performing said cooling after said wafer is bound to said electrostatic chuck.

7. The method of claim 6 including cooling said wafer during processing in said follow-on processing chambers during semiconductor processing of said wafer.

8. The method of claim 1 including moving said wafer into said load lock on said electrostatic chuck following processing of said wafer in said follow-on processing chambers and moving said wafer from said electrostatic chuck by transferring to an area of said non-contact chuck without contacting the facing surface of said wafer with said non-contact chuck and then moving said wafer out of said load lock and into atmosphere.