Interface behaviour and electrical performance of ruthenium Schottky contact on 4H-SiC after argon annealing

Abstract

Rutherford backscattering spectrometry(RBS) analysis , carried out at various annealing temperatures, of a thin film of ruthenium on n-type 4-hexagonal silicon carbide (4H-SiC) showed evidence of ruthenium oxidation, ruthenium silicide formation and diffusion of ruthenium into silicon carbide starting from an annealing temperature of 400oC. Ruthenium oxidation was more pronounced, and ruthenium and Silicon inter-diffusion was very deep after annealing at 800oC. Raman analysis of some samples also showed ruthenium silicide formation and oxidation. The Schottky barrier diodes showed very good linear capacitance-voltage characteristics and excellent forward current-voltage characteristics, despite the occurrence of the chemical reactions and inter-diffusion of ruthenium and silicon at ruthenium-silicon-carbide interface, up to an annealing temperature of 800oC.