Date of Award
Master of Science in Materials Science and Engineering - (M.S.)
Committee for the Interdisciplinary Program in Materials Science and Engineering
Roland A. Levy
James M. Grow
David S. Kristol
Silicon nitride thin films were deposited on silicon substrates using Diethylsilane (DES) and ammonia by Plasma Enhanced Chemical Vapor Deposition (PECVD) over a temperature range of 100 - 300°C, a pressure range of 0.2 - 0.6 torr, and a ratio of NH3/DES was varied from 6 - 26. The R.F. power and frequency were kept at 0.15 watts/cm2 and 100 KHz respectively. DES flow rate was set at 15 sccm for all experiments in this study. One set of experiments were performed at different values of one parameter while the other parameters were kept constant.
The deposition rate was found to be directly proportional to the chamber pressure, but inversely proportional to the deposition temperature and to the NH3/DES ratio. The composition of the deposits were determined by ESCA, which found that all films had relatively large concentration of carbon. The carbon content in the films was affected by the reactant ratio, and could be decreased by increasing NH3/DES ratio. All films as deposited had a compressive stress. Heat-treatment at temperature higher than the deposition temperature lead to a densification of the film and results in films that are less compressive. The increase in NH3/DES ratio has the effect of increasing the Young's modulus and hardness. This can be explained by saying that the more nitrogen in the film, the higher the Young's modulus.
Yu, Yanyao, "Synthesis and characterization of silicon nitride films deposited by plasma enhanced chemical vapor deposition using diethylsilane" (1993). Theses. 2214.