Gettering is very important technique for IC manufacturing. Backside damage is one of the gettering techniques. A method of introducing backside damage into silicon wafer for gettering, which utilizes cavitation impacts, is presented. Because intensity of cavitation impacts can easily be controlled, cavitation impacts caused by a cavitating jet were used. The impacts of cavitation bubble collapses were controlled by injection pressure and distance from a nozzle to the silicon wafer surface. The surface of silicon wafer treated by the cavitating jet was demonstrated. On the surface of silicon wafer treated by the cavitating jet followed by heat treatment, oxidation-induced stacking faults that are effective as gettering sites were observed. This fact means that cavitating jet can be used to introduce backside damage for gettering. The distribution of impacts caused by cavitation bubble collapses was measured to estimate magnitude of impact to introduce suitable damage. In order to expand exposed area, the surface of silicon wafer was scanned by moving the nozzle. X-ray diffraction from exposed area was measured compared with that from not exposed area. The diffractive angle on exposed area was different from not exposed area.