Investigation of Solid State Reactions of Pd Films on Single-Crystal 6H-SiC

Abstract

The solid state reactions between Pd films deposited by resistive evaporation on 6H-SiC substrates have been investigated by Rutherford backscattering spectrometry (RBS) scanning electron microscopy (SEM), Raman spectroscopy and glancing-incidence xray diffraction (GIXRD). The deposited films were subsequently annealed from 200 to 800°C in vacuum. At room temperature, no silicides were detected to have formed at the Pd/SiC interface. The as-deposited Pd films formed a flat and chemically inert interface with SiC. After annealing at 400°C, a reaction zone was formed between Pd and 6H-SiC. The initial phase to form in the Pd-SiC samples were Pd4Si and Pd3Si. After annealing the Pd/SiC samples at 600°C, the contact structure consists of unreacted Pd, Pd3Si and carbon. During annealing at 700°C and 800 °C, Pd film had completely reacted with SiC resulting in a reaction zone consisting of Pd2Si and C in a graphite state. Raman analysis of the Pd-SiC samples annealed in a vacuum at 700 and 800 °C showed clear D and G carbon peaks which was evidence of formation of graphite at the surface of the Pd/SiC samples.