DIFFUSION OF GROUP-III AND GROUP-V ELEMENTS IN SILICON DURING SHORT-TERM HEAT-TREATMENT

Diffusion of Group III and V dopants in Si is considered for short-ter m annealing. These dopants migrate through Si vacancies in different c harge states. Since the electronic subsystem reaches equilibrium quick ly enough, the equilibrium concentration of vacancies in different cha rge states sets in, as controlled by the substituent concentration. An increase in the dopant concentration causes an increase in the vacanc y concentration at the interface and results in an enhanced influx of the dopant into silicon. Therefore, diffusion of Group III and V dopan ts in Si can be described in terms of nonlinear diffusion waves. The a nalytical expressions derived are used to calculate diffusion profiles of B, P, and As.