EPITAXIAL AND THERMAL STRAINS IN OXIDIC THIN-FILMS ON SI(001)

The integration of oxidic buffer layers on silicon wafers with a latti ce mismatch of up to 5% at the deposition temperature is investigated via reflection high energy electron diffraction and transmission elect ron microscopy (TEM). The strain relaxation during the deposition is o bserved in situ by monitoring the lattice parameter the results can be compared with TEM images recorded after the deposition, The decrease in the strained yttria-stabilized zirconia lattice parameter on the si licon substrate proceeds within 5-7 nm to its equilibrium value. The r esults are used for better accomodation of multilayer packages and to reduce the epitaxial stresses in the overlayer films. Results of high temperature superconducting thin films on buffer layers with reduced e pitaxial stresses are presented.