Patent ID: 6222991
Filing Date: 2001-04-24
Classification: H01L

Abstract:
A process for degassing a semiconductor substrate and also orienting the substrate in the same vacuum chamber which comprises:a) providing a vacuum chamber;b) supporting a semiconductor substrate on a heated electrostatic clamping structure functioning as a substrate support for retaining said semiconductor substrate in thermal communication therewith in said vacuum chamber;c) heating said electrostatically clamped substrate in said vacuum chamber to a temperature sufficiently to degas said electrostatically clamped substrate by providing a heater within said electrostatic clamping structure;d) rotating said substrate in said vacuum chamber while heating and degassing said semiconductor substrate; ande) while simultaneously rotating said substrate, and heating said semiconductor substrate to degas it, aligning said semiconductor substrate in said vacuum chamber using a water alignment mechanism capable of a detecting the rotational alignment of said substrate in response to said rotating of said substrate, said aligning step further comprising:i) directing a beam of light perpendicular to the plane of said substrate from a light source on one side of said substrate; andii) detecting said beam of light from said light source with a photodetector on an opposite side of said substrate when said beam of light encounters a non-circular portion of said substrate as said substrate rotates.