Patent ID: 6815352
Filing Date: 2004-11-09
Classification: C30B,H01J

Abstract:
A silicon focus ring comprising silicon single crystal used as a focus ring in a plasma apparatus, wherein, in order to produce an intrinsic heavy metal gettering effect of the focus ring, a concentration of interstitial oxygen contained in the silicon focus ring is not less than 5Ã—1017 atoms/cm3 and not more than 1.5Ã—1018 atoms/cm3, and a nitrogen concentration in the silicon focus ring is not less than 5Ã—1013 number/cm3 and not more than 5Ã—1015 number/cm3, the intrinsic gettering effect exceeding a corresponding effect for silicon not doped with interstitial oxygen and nitrogen, and the surface of the silicon focus ring is subjected to etching treatment to remove a mechanical damage layer.