Diffusion, Complexing and Precipitation of Transition Metals in Silicon

Abstract

ABSTRACTThe diffusion, solubility, complexing, and gettering of transition metals in silicon are reviewed with special emphasis on the observed chemical trends. 3d metals appear dominantly on interstitial sites in thermal equilibrium. Their diffusivity and solubility increases markedly with atomic number. Going from the 3d metals vertically down in the periodic table, a clear trend towards substitutional solution is obvious. Observation of deep level defects, complexing and gettering is strongly dependend on the respective mobility of the metal atoms. Understanding of the thermodynamics of complexing and gettering allows to define heat treatment procedures favourable to minimize detrimental effects from transition metals in silicon.