Electrical and Structural Properties of Si/CrSi sub 2 /Si Heterostructures Fabricated Using Ion Implantation

Using high dose implantation of Cr sup (+) into (111)-oriented Si followed by annealing (mesotaxy[1]), we have fabricated buried, single crystal layers of CrSi sub 2 in Si. Rutherford Backscattering and channeling analysis shows that the layers have sharp interfaces and X sub (min)'s of ~25%, which can be reduced to 14% with rapid thermal annealing (RTA). Although not much is known about its properties, CrSi sub 2 is thought to be a narrow bandgap semiconductor. The temperature dependence of the resistance of these layers shows that they are semiconducting and can be distinguished from the surrounding silicon. Hall measurements indicate that the material is p-type with ~10 sup 19 carriers/cm sup 3. The data shows evidence of impurity levels in the bandgap and experiments are underway to compensate these by doping with MN. [1] Alice E. White, K.T. Short, R.C. Dynes, J.P. Garno, and J.M. Gibson, Applied Physics Letters 50: 95 (1987)