PROGRESS IN THE USE OF SPRAYED BORIC ACID AS A DOPANT SOURCE FOR SILICON RIBBONS

摘要

This paper reports on an alternative method for boron doping of silicon ribbons based on the use of sprayed boric acid as a dopant source. The sprayed pre-ribbon is subjected to zone melting recrystallization in an argon atmosphere. Boron incorporation occurs via two mechanisms: solid-state diffusion and vapor-phase contamination. In the molten zone the boron is uniformly mixed due to convection in the liquid. It is shown that one may control the incorporation of boron by changing the initial concentration of boric acid on the surface of the sample. It is also established how the incorporation of boron depends on parameters such as the direction of recrystallization and the flux of argon in and out of the furnace.