Investigation of microstructure and chemical composition of Ni contacts to n-type 4H-SiC

Structure and chemical compositions of the interface layer obtained after nickel deposition on silicon carbide surface and subsequent annealing have been analyzed using time-of-flight secondary ion mass spectrometry (TOF-SIMS), X-ray diffraction (XRD) and Raman spectroscopy. Nickel silicide (Ni2Si) were characterized as the main product of reaction between nickel and silicon carbide after annealing at temperatures range 700-1000 degrees C. Raman spectroscopy and TOF-SIMS profiling results confirmed carbon precipitation within contact layer. Obtained results indicate graphitic form of carbon and its non-uniform distribution in the contact layer. Moreover, TOF-SIMS analysis showed modification of nitrogen distribution in the contact area upon Ni/SiC contact annealing. (C) 2012 Elsevier B.V. All rights reserved.