The manner which removes the heavy metal impurity in the semiconductor wafer and production manner null of the semiconductor wafer which possesses this

摘要

PROBLEM TO BE SOLVED: To obtain a high-quality semiconductor wafer, as well as to improve the manufacturing yield, productivity, electrical characteristics, and the like of a semiconductor device which is being manufactured, by having heavy metal impurities aggregated in a wafer on or near a surface and by eliminating a heavy metal aggregation layer. ;SOLUTION: Although a negative electric field applied to a P-type silicon wafer turns a surface layer into accumulating state, a heavy metal with positive charges in bulk is pulled near a surface due to the bending of a band. In a method for applying the electric field to make the heavy metal in the wafer aggregate on or near the surface, the surface of the wafer may not always e negatively charged, by causing negative ions are to exist on the surface of the wafer as in a corona discharge treatment, heavy metal impurities can be aggregated onto the surface. Then, the heavy metal impurities which aggregated on the surface of the wafer may be removed through etching, polishing, grinding, or the like that is normally performed for the semiconductor wafer.;COPYRIGHT: (C)1999,JPO