| 摘要 |
PURPOSE:To decrease the concentration of oxygen within a wafer substantially and to improve the yield of circuit elements, by diffusing a highly oxidizable metal on the opposite face of a semiconductor wafer to that on which the circuit elements are provided. CONSTITUTION:Circuit elements are arranged on the surface 2 of an Si wafer 1 or on the surface 2 of an epitaxial layer deposited on the wafer 1 while, on the rear face, a highly oxidizable metal 5 such as Al, Ti or B is predeposited to a thickness of several mum by means of CVD or the like. Since control of O2 can be performed only very insufficiently during this process, the wafer is heat treated again at 1100-1300 deg.C so as to diffuse the metal 5 into the wafer and to distribute it as shown at 5'. In this manner, the concentration of oxygen within the wafer 1 can be decreased, any metal contaminating an active region can be gettered and slippage of crystals can be decreased.
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