Formation of TiSi thin films on stressed 001/Si substrates

The effects of stress on the formation of TiSi2 thin films have been investigated. Compressive stress present in the silicon substrate was found to retard significantly the transformation of high-resistivity C49-TiSi2to 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 thickness of TiSi2 films was found to decrease and increase with the compressive and tensile stress level, respectively. In addition, the thickness of amorphous interlayers a-interlayers.between Ti films and silicon substrates was found to be thicker and thinner in the compressively and tensile-stressed samples, respectively. The results indicated that the compressive stress hinders the migration of Si through the TirSi interface, so that the transformation of C49- to C54-TiSi2 is retarded. In contrast, the tensile stress promotes the Si diffusion to facilitate the formation of C54-TiSi2. q1999 Elsevier Science B.V. All rights reserved