Effect of Impurities on Growth of Ti Silicides in Bulk Ti/Si Diffusion Couple

摘要

Reaction diffusion and the Kirkendall effect in Ti-Si binary system have been studied by using sandwich-type bulk diffusion couples consisting of 99.99/100 Ti, 99.9999/100 Ti plates and a (111) oriented Si wafer. The results have been com- pared with our previous one obtained by using 99.99/100 Ti/Si and 99.5/100 Ti/Si couples. The faster growth of TiSi_2 formed in these Ti/Si diffusion couples, the higher the purity of titanium. To identify the element which slows down the growth rate of TiS_2, the effects of oxygen, nitrogen, carbon and iron were studied by adding oxygen and nitrogen into 99.9999/100 Ti or by depositing carbon and iron on the Ti surface. It has been clarified that iron atoms slow down the growth of TiSi_2.