Structural and Electrical Properties of P- and B-Doped Polycrystalline Silicon by Plasma-Enhanced CVD at 700°C

Undoped, P- and B-doped polycrystalline Si films were prepared on a fused quartz substrate at 700°C by low-pressure CVD (LPCVD) and plasma-enhanced CVD (PECVD) using the same fabrication system. The effects of plasma supply on the structural and electrical properties were investigated. All of the PECVD films show a strong < 110 > texture, in contrast with LPCVD films with a nearly random texture. Plasma supply also has the effect of essentially smoothing the surface, independent of the doping level of either dopant, and for improvement of the P- and B-doping efficiency in an intermediate doping range.