Abstract: A method and apparatus for depositing a boron insitu doped amorphous or polycrystalline silicon film on a substrate. According to the present invention, a substrate is placed into deposition chamber. A reactant gas mix comprising a silicon source gas, boron source gas, and a carrier gas is fed into the deposition chamber. The carrier gas is fed into the deposition chamber at a rate so that the residence of the carrier gas in the deposition chamber is less then or equal to 3 seconds or alternatively has a velocity of at least 4 inches/sec. In another embodiment of forming a boron doped amorphous for polycrystalline silicon film a substrate is placed into a deposition chamber. The substrate is heated to a deposition temperature between 580-750° C. and the chamber pressure reduced to a deposition pressure of less than or equal to 50 torr. A silicon source gas is fed into the deposition at a rate to provide a silicon source gas partial pressure of between 1-5 torr.