Chemical vapor deposition of silicon nitride thin films from tris(diethylamino)chlorosilane

In an attempt to synthesize amorphous silicon nitride (a-SiN_x) thin films with minimal incoporation of impurities, a novel liquid precursor, tris(diethylamino)chlorosilane (TDEACS), was synthesized and proven to be an ideal candidate as a silicon and nitrogen source for depositing of high-quality a-SiN_x thin films. a-SiN_x films with low carbon and hydrogen contents were prepared from a TDEACS-NH₃-N₂ system by the LPCVD technique. The films were characterized by X-ray photoelectron spectroscopy, Auger depth profile, Fourier transform infrared spectroscopy, elastic recoil detection, and atomic force microscopy, respectively. Carbide-containing a-SiN_x films were obtained at lower NH₃/TDEACS ratios while all deposits were essentially stoichiometric at higher NH₃/TDEACS ratios. Both carbon and hydrogen contents of the as-prepared a-SiN_x films were markedly lower than of those prepared from other organic precursors previously reported. The surface topography of the as-prepared film was smooth and uniform with a root-mean-square roughness of 0.53 nm.