ION-BEAM SYNTHESIS BY TUNGSTEN-IMPLANTATION INTO 6H-SILICON CARBIDE

Synthesis of a highly conductive surface layer on 6H-silicon carbide w as achieved by high-dose, room temperature implantation of tungsten at 200 keV. Subsequently, the samples were annealed in two steps, namely at 500 degrees C and 950 degrees C. The influence of both dose and an nealing on the reaction of W with SiC was investigated. Rutherford Bac kscattering Spectrometry (RBS), X-Ray Diffraction (XRD) and Auger Elec tron Spectroscopy (AES) contributed to study the structure and composi tion of the layer as well as the chemical states of the elements. Duri ng implantation sputtering becomes significant for doses exceeding 1.0 X 10(17) cm(-2). Formation of tungsten carbide and silicide is alread y observed in the as-implanted state. An annealing temperature of 950 degrees C is necessary to crystallize tungsten carbide. However, tungs ten silicide remains amorphous at this temperature. Therefore, a mixtu re of polycrystalline tungsten carbide and amorphous tungsten silicide develops under these conditions. The resistivity of such a layer impl anted with 1.0 X 10(17) W+ cm(-2) and annealed at 950 degrees C is 565 mu Omega cm.