Theoretical model and computer simulation results of enhanced diffusion of high-temperature implanted aluminum in silicon carbide

Abstract

Wide application of silicon carbide (SiC) films in microelectronics devices makes especially important predictions of the doping profiles during and/or after thermal treatment. A macroscopic kinetic model of enhanced diffusion of aluminum in SiC films during ion bombardment at high temperature has been considered. The set of equations describing the kinetic model takes into account generation of Si and C dangling bonds during bombardment, formation of C-Al and Si-Al bonds, migration of the mobile species (aluminum) to the surface, their reactions with Si and C dangling bonds as well as their evolution from the film. Numerical simulation of the equations has allowed the total concentration profile of Al implanted into SiC to be determined, the concentration profile of Al atoms on C and Si dangling bonds, the concentration profile of mobile and immobile Al atoms. The calculations were carried out for Al implanted with 40 kev energy and an ion current density of 20 /spl mu/A/cm/sup 2/ to a dose 2/spl times/10(16) cm/sup -2/ at 1800/spl deg/C. The calculations show that the Al content in SiC did not exceed 40%. We obtained a good agreement with experimental profile of Al.