Method of manufacturing a semiconductor device including a gettering operation

摘要

A gettering layer for capturing heavy metal impurities is formed on a wafer back surface. Immediately before formation of a metal wiring layer, a semiconductor device is subjected to first heat treatment at a predetermined temperature so that the heavy metal impurities are heat-diffused and captured in the gettering layer. The gettering layer with the heavy metal impurities captured therein is removed before second heat treatment following the first heat treatment. After removing the gettering layer, a first amorphous silicon layer as a filler for filling a contact hole is deposited on a wafer device surface including a device active region while a second amorphous silicon layer having an impurity concentration equal to that of the first amorphous silicon layer is simultaneously deposited on the wafer back surface.