A study of moderatelyin situdoped polycrystalline silicon deposition fromSiH4, PH3,andH2by single-wafer reduced pressure chemical vapor deposition has been carried out. The process window which yielded P concentrations on the order of1019 cm−3was a pressure of 80 Torr in a hydrogen carrier with aPH3/SiH4mole fraction range of0.1×10−4–1×10−4,and temperatures of 600–700 °C. It was found that thePH3/SiH4mole fraction in this process window has little effect on the deposition rate unlike the rate reduction caused byPH3in a saturation-doped polysilicon process with doping levels in excess of1020 cm−3.The activation energy of the process, 48kCal mol−1,over this temperature range approaches one of a hydrogen desorption limited process, 49kCal mol−1,suggesting that the deposition rate is dominated by the highH2pressure. The transition of the as-deposited film structure from predominately amorphous to completely polycrystalline occurs at about 675 °C, about 100 °C higher than in typical low-pressure chemical vapor deposition and is likely due to a combination of highH2pressure and high deposition rates. To a first order, the post-anneal film resistivity appears to be dominated by the grain structure and not by the P incorporation rate in the moderately doped concentration regime.