Modelling of Intrinsic Aluminum Diffusion for Future Power Devices

Aluminum as the fastest diffusing acceptor dopant in silicon is commonly used for the fabrication of power semiconductors with p n junctions depths ranging from microns to more than hundred micron. Although used since long, its diffusion behavior is not sufficiently characterized to support computer aided design of new devices. Since modern processes are rather based on low temperatures, the inert diffusion of aluminum was investigated in the temperature range from 850 to 1100 C. Combining nitridation and oxidation experiments, the fractional diffusivity via self interstitials was determined.