Boron nitride films have been deposited in an Applied Materials-730 Nitrox reactor by a reaction between ammonia and diborane in an inert carrier gas. The deposition rate was proportional to the flow rate of diborane and to the negative l/5th power of the flow rate of ammonia. For a fixed NH3/B2H6 ratio, the deposition rate increased linearly with the flow rate. The deposition rate increased with temperature in the temperature range of 400°-700°C; at higher temperatures, the rate was nearly independent of temperature. For temperatures ≥700°C, the stress in the film was compressive. At lower temperatures, tensile films could be deposited at sufficiently high flow rates. The refractive index, which ranged from 1.7 to 2.8, decreased with increasing temperature, NH3/B2H6 ratio, and the flow rate. The B/N concentration ratio of the films was found to vary from 0.7 to 4. Films richer in boron were tensile and had high refractive indexes. Phosphorus doping of the films was studied in the hope of finding new means for controlling important film properties such as stress. Although films were successfully doped with phosphorus, such doping had little effect on the stress, deposition rate, or the refractive index. © 1979, The Electrochemical Society, Inc. All rights reserved.
