Structural and electrical characterisation of nickel silicides contacts on silicon carbide

The interfacial reaction and phase formation as a function of the annealing temperature (600+1000¬?C) and times were investigated on nickel thin films evaporated on n type 6H-SiC (0001) substrate. The study was carried out employing a combination of Rutherford Backscattering Spectrometry, X-Ray Diffraction, Transmission Electron Microscopy and sheet resistance measurements. Also several TLM structures and Schottky diodes were fabricated with the same processes and a correlation has been found between the annealing process and the electrical measurements. The only nickel silicide phase that has been observed between 600 and 950 ¬?C was the Ni2Si. The carbon of the consumed silicon carbide layer has been dissolved in the silicide film, during the reaction, forming carbon precipitates. The Ni2Si/SiC Schottky diodes show an almost ideal characteristics (n=1.07) and a barrier height of about 1.3 eV. From the electrical characterisation a non uniform Schottky barrier height seems to be formed. ¬© 2001 Materials Research Society.