Effect of interfacial silicon on the structural stability of C54-TiSi2 on SiO2

The formation of interconnect C54-TiSi2 on SiO2 substrates suffers severe structural instability upon rapid thermal anneal. To understand the structural instability from a mechanistic point of view, we investigated the interfacial features of the C54-TiSi2 on SiO2 using Auger electron spectroscopy and cross-sectional transmission electron microscopy. As a result, we noted that the surplus silicon layer retained at the interface between the C54-TiSi2 thin film and the SiO2 substrates is indispensable for the stabilization of the C54-TiSi2 on SiO2. We explained the affirmative role of the silicon layer retained at the interface in terms of the residual stress of the C54-TiSi2 thin film. (C) 2000 American Institute of Physics. [S0003-6951(00)01325-5].