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Title: Micromachined silicon electrostatic chuck

An electrostatic chuck is faced with a patterned silicon plate 11, created y micromachining a silicon wafer, which is attached to a metallic base plate 13. Direct electrical contact between the chuck face 15 (patterned silicon plate's surface) and the silicon wafer 17 it is intended to hold is prevented by a pattern of flat-topped silicon dioxide islands 19 that protrude less than 5 micrometers from the otherwise flat surface of the chuck face 15. The islands 19 may be formed in any shape. Islands may be about 10 micrometers in diameter or width and spaced about 100 micrometers apart. One or more concentric rings formed around the periphery of the area between the chuck face 15 and wafer 17 contain a low-pressure helium thermal-contact gas used to assist heat removal during plasma etching of a silicon wafer held by the chuck. The islands 19 are tall enough and close enough together to prevent silicon-to-silicon electrical contact in the space between the islands, and the islands occupy only a small fraction of the total area of the chuck face 15, typically 0.5 to 5 percent. The pattern of the islands 19, together with at least one hole 12 bored throughmore » the silicon veneer into the base plate, will provide sufficient gas-flow space to allow the distribution of the helium thermal-contact gas.« less
Inventors:
 [1];  [1]
  1. (Albuquerque, NM)
Issue Date:
OSTI Identifier:
870736
Assignee:
United States of America as represented by Department of Energy (Washington, DC) SNL
Patent Number(s):
US 5583736
Contract Number:
AC04-76DP00789
Research Org:
AT & T CORP
Country of Publication:
United States
Language:
English
Subject:
micromachined; silicon; electrostatic; chuck; faced; patterned; plate; 11; created; micromachining; wafer; attached; metallic; base; 13; direct; electrical; contact; 15; surface; 17; intended; hold; prevented; pattern; flat-topped; dioxide; islands; 19; protrude; micrometers; otherwise; flat; formed; shape; 10; diameter; width; spaced; 100; apart; concentric; rings; periphery; contain; low-pressure; helium; thermal-contact; gas; assist; heat; removal; plasma; etching; held; tall; close; prevent; silicon-to-silicon; space; occupy; fraction; total; typically; percent; 12; bored; veneer; provide; sufficient; gas-flow; allow; distribution; pressure helium; electrostatic chuck; concentric rings; plasma etching; direct electrical; base plate; electrical contact; silicon wafer; heat removal; silicon dioxide; provide sufficient; silicon plate; plasma etch; patterned silicon; metallic base; flat surface; /361/279/