Abstract
Abstract The effects of stress on the formation of titanium silicides with SOI (silicon-on-insulator) wafers have been investigated by sheet resistance measurements glancing-angle x-ray diffraction analysis and transmission electron microscopy. The tensile stress present in SOI wafers was found to influence significantly on the phase transformation from C49 to C54-TiSi2. Tensile stress was induced by the difference of thermal expansion coefficients of Si and SiO2. The thinner the top silicon layer, the higher tensile stress was induced. For titanium on blank and SOI substrate after rapid thermal process (RTP) at 600-900 ℃ for 30 sec, it was found that early phase transformation of C49 to C54-TiSi2 occurred with SOI substrate. Furthermore discussed with SOI wafers in detail, the thinner the top silicon layer, the earlier phase transformation was carried out. The results indicated that the tensile stress enhances the phase transformation from C49 to C54-TiSi2.