Simulations and experiments on external gettering of silicon

Simulation results are presented of external gettering of impurities in Si by P‐indiffusion, a liquid Al layer, and both of these in tandem. Out of P‐indiffusion and liquid Al layer gettering, the former gives faster gettering, while the latter gives more stable gettering and has a higher gettering capacity. The two in tandem give fast gettering combined with a stable gettering process and high gettering capacity. Experimental results are presented showing improvement of minority carrier diffusion length in silicon by external gettering of impurities by a liquid Al layer. Gettering by the Al layer can give protection from contamination arising from the furnace environment, and repeated application of the gettering process is more effective than just increasing the thickness of the gettering layer in a single application of the gettering process.