Formation of TiSi2 thin films on stressed (001)Si substrates

The effects of stress on the formation of TiSi2 thin films have been invest igated. Compressive stress present in the silicon substrate was found to re tard significantly the transformation of high-resistivity C49-TiSi2 to low- resistivity C54-TiSi2. On the other hand, the tensile stress present in the silicon substrate was found to promote the formation of C54-TiSi2. For Ti on stressed (001)Si substrates after rapid thermal annealing (RTA), the thi ckness of TiSi2 films was found to decrease and increase with the compressi ve and tensile stress level, respectively. In addition, the thickness of am orphous interlayers (a-interlayers) between Ti films and silicon substrates was found to be thicker and thinner in the compressively and tensile-stres sed samples, respectively. The results indicated that the compressive stres s hinders the migration of Si through the Ti/Si interface, so that the tran sformation of C49- to C54-TiSi2 is retarded. In contrast, the tensile stres s promotes the Si diffusion to facilitate the formation of C54-TiSi2. (C) 1 999 Elsevier Science B.V. All rights reserved.