Mechanical damage gettering effect in Si

The gettering effectiveness of microdefects in Si wafer with mechanical damage introduced deliberately is investigated in relation to the degree of damage and the stress field around the damage. It is found that gettering action continues for 8 hours or more, although slower, when the damage is applied to a deep part of the wafer. This is due to the fact that the dislocations introduced deep in the wafer continue to serve as sinks for microdefect nuclei. The gettering effect is also greatly dependent on the microdefect density of a wafer.