Synthesis, Characterization, and Thermal Properties of Chlorine‐Containing 1,1,2,2‐Tetraaminodisilanes and Their Potential as Chemical Vapor Deposition Precursors for Silicon Nitride Films

Abstract

Three chlorine‐containing aminodisilanes of the type Cl(RR′N)2Si–Si(NRR′)2Cl (with R = alkyl and R′ = H or R) as potential chemical vapor deposition (CVD) precursors for silicon nitride (SiNx) films have been synthesized and characterized by X‐ray diffraction; 1H, 13C, and 29Si NMR spectroscopy; and elemental analysis. They were obtained in high yields by the reactions of hexachlorodisilane (Si2Cl6) with excess liquid amines in diethyl ether through a general single‐step procedure. Their thermal properties including stability, volatility, transport behavior, and vapor pressure were evaluated by thermogravimetric analysis (TGA) to confirm that they are suitable for the CVD procedure. The deposition of SiNx films was accomplished with a hot‐wall CVD reactor system, which preliminarily verified the suitability of these compounds as CVD precursors.

Theoretical study on the reaction mechanism of Si2Cl6 and HCl catalyzed by amine catalysts

“…Due to the lower energy barrier in the second step, the intermediates will not accumulate, and SiHCl 3 and SiCl 4 are simply generated as products, facilitating catalyst recycling. Du et al 41 experimentally investigated the amination pathway of chlorosilanes and successfully synthesized Si 2 (R 2 N) 4 Cl 2 crystals. This proves the authenticity of the path proposed by Zhang and increases our study's feasibility.…”