In situ strain measurements during the formation of palladium silicide films

The evolution of strain in the Pd–Si system during the growth of Pd2Si thin films on Si (100) substrate has been followed in situ using a double optical beam technique. As was observed for the Pt–Si system, the reaction to form Pd2Si yields a compressive intrinsic surface film stress as well as for the silicon-rich silicides as proposed by Angilello et al. [Thin Film Interfaces and Interactions, edited by J. Baglin and J. Poate (The Electrochemical Society, Pennington, NJ, 1980)]. A transmission electron microscopy analysis has revealed grain growth during the formation of Pd2Si which cannot account for the compressive film stresses. The formation of silicide at the interfaces rather than the overall change in volume agrees with the sign of the stresses formed.