High-temperature zinc doping of silicon from zinc-containing SiO2 films

Abstract

Experimental evidence is presented that high-temperature annealing of Zn-containing SiO2 films on Si gives rise to phase separation, accompanied by the formation of Zn-enriched bands. Appreciable amounts of zinc (sufficient to change the conductivity type of Si and to raise its resistivity) diffuse to only small depths (≤10 μm) and at relatively short diffusion times. Long-term high-temperature annealing reduces the Zn concentration in the film. This process can be inhibited by applying a protective SiO2 layer.