Patent ID: 6273992
Filing Date: 2001-08-14
Classification: G01N,Y10S

Abstract:
An apparatus for rapid decomposition of a silicon oxide layer on a silicon wafer by the controlled application of a mist containing HF comprising:(a) a table for supporting a silicon wafer;(b) a cylindrical dome assembly positioned over said table comprising:(i) a first portion which is dome shaped having an opening at its apex and a lower lip with a diameter greater than the diameter of said wafer and a spacing which is formed between the plane of said wafer and said lip when said dome assembly is lowered concentrically over said wafer; and(ii) a second portion comprising a tube disposed axially to said first portion and having a lower section extending through and sealed to said opening terminating within said first portion and an upper section fitted with at least one sidearm and a gas inlet comprising a vortex tube;(c) means for providing a first gas flow to said vortex tube;(d) means for raising and lowering said dome assembly;(e) means for recovery and disposition of exhaust gases; and(f) a mist generator having a discharge tube connected to said at least one sidearm, said mist generator comprising:(i) A body having a lower portion which forms a reservoir for a liquid and an upper portion containing baffles;(ii) means for heating said reservoir;(iii) a bubbler located in said reservoir;(iv) means for providing a second gas flow to said bubbler; and(v) means for heating a mist flow in said discharge tube.