| 摘要 |
PROBLEM TO BE SOLVED: To simply reduce a concentration of a wafer carrier in a relative short time to the extent that a Schottky barrier diode can be prepared in a p-type silicon wafer of low resistance. SOLUTION: The p-type silicon wafer is boiled as-immersed in boiled pure water for 20-40 min, the wafer is then taken out from the boiling pure water and is immersed in an aqueous hydrofluoric solution of a concentration of 1-10 wt.% at a temperature of 15-35 deg.C for 1-5 min. Thereafter, the wafer is taken out and rinsed with pure water. After the above operation is repeated 20 times, the wafer is immersed in pure water at a temperature of 40-80 deg.C for 20-40 min. Then, the wafer is taken out from the pure water and is immersed in an aqueous hydrofluoric solution of a concentration of 1-10 wt.% at a temperature of 15-35 deg.C for 1-5 min, then, the wafer is rinsed with pure water.
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