Patent ID: 7633305

Claim:
A method for evaluating an SOI wafer, the method comprising: contacting a surface of the SOI wafer with a wafer chuck holding surface, the wafer chuck holding surface comprising a mercury electrode, said surface of the SOI wafer being held on the wafer chuck holding surface and in contact with the mercury electrode; and measuring an electric characteristic of the SOI wafer with the mercury electrode while the mercury electrode is in contact with said surface of the SOI wafer; wherein: said surface of the SOI wafer is an outer surface of a MESA part of the SOI wafer, said MESA part is a remaining portion of an SOI layer after a portion of the SOI layer is removed from the SOI wafer; and a diameter of an outermost periphery of the wafer chuck holding surface is equal to or greater than 0.5 and less than 1.0 times a diameter of an outermost periphery of said surface of the SOI wafer.