Low pressure chemical vapor deposition of silicon nitride films from ditertiarybutylsilane

In this study amorphous stoichiometric silicon nitride films were synthesized by low pressure chemical vapor deposition (LPCVD) using DTBS (ditertiarybutylsilane) and ammonia (NH3). The growth kinetics were determined as a function of temperature in the range of 600-900 00, pressure in the range of 0.2-1.1 Torr, DTBS flow rate in the range of 10-50 sccm, and NH3/DTBS flow ratio in the range of 5-20. At constant condition of pressure (0.5 Torr), DTBS flow rate (10sccm) and NH3 flow rate (100 sccm), the deposition rate of as-deposited silicon nitride films was found to follow an Arrehnius behavior in the temperature range of 600-700 °C with an activation energy of 50.0±0.2 kcal mol-1. The film characterizations including physical, compositional, structural, optical and mechanical properties were determined by using Nanospec Interferometry, XPS, RBS, X-ray diffraction, FTIR, UV Visible, Ellipsometer, and Nano Instrument Indenter. The obtained results demonstrated the feasibility of using DTBS in the synthesis of high quality silicon nitride films by LPCVD. Furthermore, some advantages of DTBS over traditional precursors were found and thus indicated that high quality amorphous silicon nitride films can be obtained from DTBS-NH3 precursor system using LPCVD by optimizing the film synthesis conditions