Interactions of fluorine redistribution and nitrogen incorporation with boron diffusion in silicon dioxide

This work investigates the effect of composition of gate dielectric on boron diffusion. Gate oxides were grown with nitrogen contents varying from 0 to 1.4%. A series of SIMS measurement were carried out to measure the depth profile of incorporated nitrogen and fluorine. Capacitance voltage measurements were used to determine the amount of boron penetration. Also, to better understand the role of fluorine, experiments were carried out to investigate the redistribution of fluorine in the poly/SiO/sub 2//Si system. Finally a model is proposed that accounts for diffusion of boron as a function of local impurity concentration in gate dielectric.