SOLID-STATE REACTION IN PD ZNSE THIN-FILM CONTACTS/

We report on solid-state reactions in Pd thin film contacts on ZnSe at temperatures below 500 degrees C. We found that a solid-state reactio n was initiated at the Pd/ZnSe interface by thermal annealing at 200 d egrees C. A tetragonal ternary phase, Pd5+xZnSe, consisting of highly oriented grains was formed as a result of this reaction. This phase is found to be stable up to an annealing temperature of 400 degrees C. T he crystallography and morphology of this ternary Pd-ZnSe phase was st udied by x-ray diffraction and transmission electron microscopy and ha s similarities to the analogous ternary Pd-GaAs phase formed in the Pd /GaAs contact structure. The Pd/ZnSe interface is found to be thermall y more stable than the corresponding Pd/GaAs and Pd/Si structures. Com parisons are made between the systematics of Pd/semiconductor interfac ial phenomena on the three semiconductors. (C) 1995 American Institute of Physics.