Department of Chemistry, University of Calgary, Calgary, Alberta, T2N 1N4 Canada.
J Phys Chem A. 2011 Sep 22;115(37):10290-8. doi: 10.1021/jp203966h. Epub 2011 Aug 25.
The effect of the Si-H bond on the gas-phase reaction chemistry of trimethylsilane in the hot-wire chemical vapor deposition (HWCVD) process has been studied by examining its decomposition on a hot tungsten filament and the secondary gas-phase reactions in a reactor using a soft laser ionization source coupled with mass spectrometry. Trimethylsilane decomposes on the hot filament via Si-H and Si-CH(3) bond cleavages. A short-chain mechanism is found to dominate in the secondary reactions in the reactor. It has been shown that the hydrogen abstractions of both Si-H and C-H occur simultaneously, with the abstraction of Si-H being favored. Tetramethylsilane and hexamethyldisilane are the two major products formed from the radical recombination reactions in the termination steps. Three methyl-substituted disilacyclobutane molecules, i.e., 1,3-dimethyl-1,3-disilacyclobutane, 1,1,3-trimethyl-1,3-disilacyclobutane, and 1,1,3,3-tetramethyl-1,3-disilacyclobutane are also produced in reactor from the cycloaddition reactions of methyl-substituted silene species. Compared to tetramethylsilane and hexamethyldisilane, a common feature with trimethylsilane is that the short-chain mechanism still dominates. However, a more active involvement of the reactive silene intermediates has been found with trimethylsilane.
采用热钨丝化学气相沉积（HWCVD）过程中硅-氢键对三甲基硅烷气相反应化学的影响，通过研究其在热钨丝上的分解以及使用软激光电离源和质谱联用的反应器中的二次气相反应来研究。三甲基硅烷在热丝上通过 Si-H 和 Si-CH(3) 键的断裂分解。发现短链机制在反应器中的二次反应中占主导地位。结果表明，Si-H 和 C-H 的氢抽提同时发生，Si-H 的抽提更有利。四甲基硅烷和六甲基二硅烷是在终止步骤的自由基重组反应中形成的两个主要产物。三个甲基取代的二硅环丁烷分子，即 1,3-二甲基-1,3-二硅环丁烷、1,1,3-三甲基-1,3-二硅环丁烷和 1,1,3,3-四甲基-1,3-二硅环丁烷，也从甲基取代的硅烯物种的环加成反应中在反应器中生成。与四甲基硅烷和六甲基二硅烷相比，三甲基硅烷的一个共同特征是短链机制仍然占主导地位。然而，与四甲基硅烷和六甲基二硅烷相比，发现反应性硅烯中间体的参与更加活跃。
