| 摘要 |
PROBLEM TO BE SOLVED: To drive away metal contaminants attendant on a silicon oxide layer into a bulk silicon and to prevent minority carriers from decreasing in life by a method, wherein a wafer processed with hydrofluoric acid is bought into contact with ozonated water, and a hydrophilic oxide layer is grown on the surface of a silicon wafer and heated at a prescribed temperature. SOLUTION: A water solution which contains hydrofluoric acid is brought into contact with the surface of a silicon wafer to remove metal particles from it. Then, the wafer processed with hydrofluoric acid is brought into contact with ozonated water, and a hydrophilic oxide layer is grown on the surface of the silicon wafer. Then, the wafer subjected to an ozoneated water treatment is heated at a temperature of 300 deg.C or so for about one second. By this setup, iron, chromium, calcium, titanium, cobalt, maganese, zinc and vanadium on the surface of a silicon wafer become smaller than 1×10<9> atom/cm<2> in concentration at a heating initial stage. Minority carriers in the silicon wafer are prevented from decreasing in life, when the silicon wafer is subjected to a heat treatment.
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