Surface morphology and electrical property evolution of super-thin Pt film on 6H-SiC substrate during annealing

Abstract

We reported the surface morphology and electrical property of super-thin Pt films, ∼2 nm thick, deposited on 6H-SiC (0001) substrates and subsequently annealed from 400 to 1000 °C. The surfaces of the films were found to have a feature of islands growth, and the sizes of the islands increased with increasing annealing temperature. Free carbon, produced by selective reactions between Pt and SiC, diffused toward the top surface across the product layers due to low solubility and composition gradient of carbon throughout the reaction zone. A dramatic change of electrical conductivity of the films was observed. A mechanism analysis reveals that the origin came from the contribution of aggregation of islands on the surface and formation of Pt silicides and a thin layer of crystalline graphite.