| abstract |
PURPOSE: To evaluate the dielectric strength of oxide film simply by slicing a single-crystal semiconductor silicon ingot into wafers, etching the wafers with a solution of hydrofluoric acid and nitric acid to remove distortion, and further etching them with an aqueous liquid of K 2 Cr 2 O 7 and hydrofluoric acid. n CONSTITUTION: A single-crystal semiconductor ingot obtained from silicon melt by the Czockralski technique or float zone process is sliced into wafers of a predetermined thickness. The wafers are etched with a solution of hydrofluoric acid and nitric acid to remove distortion, and further etched with an aqueous liquid of K 2 Cr 2 O 7 and hydrofluoric acid for a predetermined time. As a result, the electric characteristic of silicon wafers, i.e., dielectric strength of oxide film, can be evaluated only by counting the number of waves in a pattern appearing on the etched surface. Therefore, it is possible to decrease the time required for polishing wafers and evaluation processes associated with wafer polishing. n COPYRIGHT: (C)1992,JPO&Japio |