A study of surface reactions during the growth of B-doped a-Si:H using the intermittent deposition technique

The intermittent deposition technique has been applied to the fabrication of B-doped a-Si:H. In this technique, growth and intermission processes (waiting time) are repeated in cycles by using a mechanical shutter, while continuously maintaining the discharge. The dark conductivities in B-doped films deposited at 150 and 200 degrees C increase with waiting time, accompanied by optical gap narrowing except when the waiting time is short. In gas exchange experiments, where B2H6 doped SiH4 is replaced by Ar during the waiting time, the conductivity of the film grown at 150 degrees C increases without the narrowing. The reactions determining the conductivity and optical gap during the waiting time are discussed.