FORMATION OF COTI BARRIER AND INCREASED THERMAL-STABILITY OF COSI2 FILM IN TI CAPPED CO SI(100) SYSTEM/

We investigated the formation of CoSi2 for Ti capped Co on (100) Si su bstrate with emphasis on the Co-Ti interaction and its effect on therm al stability. A 15 nm thick Ti capping layer is shown to improve the i nterfacial roughness and thermal stability of CoSi2 film grown on Si s ubstrate compared with TiN capping. The increased uniformity of silici de/Si(100) interface is speculated to result from retarded Co-Si react ion by the formation of CoTi binary phase. And the high thermal stabil ity can be explained by the fact that the amount of Ti atoms in CoSi2 film for Ti capping is much higher than what is in TiN capping. It is likely that the surface Ti diffuses rapidly into CoSi2 grain boundarie s and slows down the agglomeration process, thereby increasing thermal stability while Ti in TiN capping did not. (C) 1998 American Institut e of Physics. [S0003-6951(98)03741-3].