화학공학소재연구정보센터
Materials Science Forum, Vol.338-3, 901-904, 2000
High temperature implant activation in 4H and 6H-SiC in a silane ambient to reduce step bunching
The mechanical strength of silicon carbide does not permit the use of diffusion as a means to achieve selective doping as required by most electronic devices. While epitaxial layers may be doped during growth, ion implantation is needed to define such regions as drain and source wells, junction isolation regions, etc. While ion implantation has been studied in all of the silicon carbide polytypes, ion activation has resulted in serious crystal damage as these activation processes must be carried out at temperatures on the order of 1600 degreesC. Ion implanted silicon carbide that is annealed in either a vacuum or hydrogen environment usually results in a surface morphology that is highly irregular due to the out diffusion of Si atoms. We have developed and report a successful process of using silicon overpressure, provided by silane in a CVD reactor during the anneal, to prevent the destruction of the silicon carbide surface. This process has proved to be robust and has resulted in complete ion activation at a annealing temperature of 1600 degreesC.