Grain growth in boron doped LPCVD polysilicon films

Abstract

Dopant induced grain growth in LPCVD polysilicon films has been investigated using BBr3 as the diffusion source at 900 and 950 °C. TEM and sheet resistance measurements indicate rapid growth under such doping conditions. Results are compared with the grain growth observed during (a) PBr3 doping of similar films, and (b) during anneals in ambients containing 1% oxygen in nitrogen, similar to that used during BBr3 or PBr3 doping. The results clearly demonstrate the rapid grain growth induced by both types of dopants, although phosphorus is more effective in inducing this grain growth.