Tungsten (W) film was deposited on a bulk single crystalline 6HeSiC substrate and annealed in H2ambient at temperatures of 700 C, 800 C and 1000 C for 1 h. The resulting solid-state reactions, phasecomposition and surface morphology were investigated by Rutherford backscattering spectrometry(RBS), grazing incidence X-ray diffraction (GIXRD) and scanning electron microscopy (SEM) analysistechniques. These results are compared with the vacuum annealed results reported in our earlier work.As-deposited RBS results indicated the presence of W and O2 in the deposited thin film, the GIXRDshowed the presence ofW,WO3, W5Si3 andWC. RBS results indicated the interaction betweenWand SiCwas accompanied by the removal of oxygen at 700 C. The GIXRD analysis indicated the presence ofW5Si3 and WC in the samples annealed at 700 C. At temperatures of 800 C and 1000 C, Wannealed ina H2 ambient further reacted with the SiC substrate and formed a mixed layer containing silicide phasesand carbide phases, i.e.W5Si3, WSi2, WC and W2C. The SEM micrographs of the as-deposited samplesindicated the W thin film had a uniform surface with small grains. Annealing at 800 C led to theagglomeration of W grains into clusters making the surface rough.
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