Comparative study of rapid and classical thermal phosphorus diffusion on polycrystalline silicon thin films

In this paper, the emitter formation on polycrystalline silicon (with grain size of 0.5–10 μm) deposited by chemical vapour deposition (CVD) on foreign substrates (thermal SiO2 and mullite ceramic) is studied. Phosphorus doping efficiency by POCl3 diffusion, APCVD+drive-in diffusion, and also rapid-thermal diffusion (RTD) from spin-on doping (SOD) sources were compared. For the first time, we report on photovoltaic results obtained on RTD-diffused emitters on pc-Si active layers deposited by rapid-thermal CVD, thus opening the way to an all rapid-thermal process for solar cell fabrication.