SLIP LENGTH IN SILICON-WAFERS CAUSED BY INDENTATION DURING HEAT-TREATMENT

The relationship between the length of slip dislocation and applied st ress in silicon wafers was investigated. Czochralski (CZ) silicon wafe rs [boron-doped, interstitial oxygen concentration [Oi] = (13.8-14.0) x 10(17)/cm(3)], indented by a Vickers hardness tester, were thermally stressed by insertion into and withdrawal from a horizontal furnace. The length of slip dislocations generated during the hear treatment wa s measured by X-ray topography (XRT). To estimate the applied thermal stress during the heat treatment, temperature distribution in the wafe r was measured with a thermocouple. From the results of XRT observatio ns, slip dislocations were found tit be generated at peripheral and ce ntral regions during the insertion and the withdrawal, respectively. T he length of slip dislocations was calculated using the experimentally estimated thermal stress. It was round that the length of slip disloc ation could be explained well by the model, with consideration of the applied stress and the dislocation velocity.