Title:
PREPARATION OF MILLER WAFER
Document Type and Number:
Japanese Patent JPS6055629
Kind Code:
A
Abstract:
PURPOSE:To sufficiently reduce the concentration of impurities in a wafer with minimum change of conventional processes, by thermally oxidizing the surface of a silicon wafer obtained by slicing an ingot before polishing the wafer. CONSTITUTION:A silicon wafer is heat-treated at an elevated temperature under oxidizing atmosphere, whereby an oxide layer (SiO2 layer) is formed on the surface of the silicon wafer. Mechanical distortion occurs on the interface between this oxide layer and the silicon crystals, and this distortion getters impurities such as heavy metals. Subsequently, the oxide layer is removed, for example by treating with fluohydric acid (HF), whereby undesirable impurities gathered on the interface of the wafer can be removed. In such a manner, the concentration of undesirable impurities such as copper, iron, nickel, chromium, sodium or the like can be reduced, in the stage of a wafer, by one tenth or more, so that a miller wafer with high purity can be obtained.
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Inventors:
OOSAWA AKIRA
HONDA KOUICHIROU
TAKIZAWA RITSUO
HONDA KOUICHIROU
TAKIZAWA RITSUO
Application Number:
JP16319383A
Publication Date:
March 30, 1985
Filing Date:
September 07, 1983
Export Citation:
Assignee:
FUJITSU LTD
International Classes:
H01L21/304; H01L21/322; (IPC1-7): H01L21/304
Attorney, Agent or Firm:
Aoki Akira