Micro-Raman study of stress distribution generated in silicon during proximity rapid thermal diffusion

Micro-Raman spectroscopy has been used for analysing the thermally induced stress distributions in silicon wafers after proximity rapid thermal diffus ion (RTD). A compressive stress was found on the whole silicon wafer after 15 s RTD. After 165 s RTD. the distribution of the stress across the wafer was found to be different: compressive at the edge and tensile at the middl e. Thermal stress was relieved in the RTD wafers via slip dislocations. The se slip dislocations were observed in the product wafers using optical micr oscopy. Slip lines propagated from the wafer edge to the wafer centre in ei ght preferred positions of maximum induced stress. The thermally induced st ress and the slip dislocation density increased with time spent at the RTD peak temperature. (C) 2000 Elsevier Science S.A. All rights reserved.