Atomic layer controlled deposition of silicon nitride with self-limiting mechanism

Thin (2-10 nm) silicon nitride films have been grown by repetitive plasma nitridation of Si using a NH3 remote plasma and deposition of Si by a SiH2Cl2 thermal reaction. The deposition rate is self-limited at nearly half-molecular layer (ML) per one deposition cycle. The process window for the half-ML/cycle of growth has been investigated with respect to the NH3 plasma power, SiH2Cl2 exposure time, and substrate temperature. The thickness fluctuation of the film over a 2 in. wafer is within measurement accuracy of the ellipsometer (+/- 1.9%) for the atomic layer controlled film while it is +/- 8.5% for all the remote-plasma chemical vapor deposition film. (C) 1996 American Institute of Physics.