HYDROGEN PASSIVATION CAUSED BY SOFT SPUTTER ETCH CLEANING OF SI

Soft sputter etch cleaning of p-type silicon (self bias range 50-150 V ) causes hydrogen passivation of boron acceptors over a depth range in the order of 1 mum. Annealing at 200-degrees-C reactivates the boron dopants. Assuming hydrogen diffusion in the RTA temperature range 155- 175-degrees-C we derive a hydrogen diffusion coefficient which is in g ood agreement with values known from literature. The diffusion activat ion energy obtained is 0.65 eV. Mobility measurements show an increase of mobility after sputter etching, proving that passivation and not c ompensation is causing the effective B-concentration reduction.