Spectroscopy and Dynamics of Group IVA Reactive Intermediates

肯塔基大学的Dennis Clouthier在实验物理化学计划的支持下，研究了各种IVA族含硅和锗的活性中间体的电子光谱和激发态动力学。各种激光光谱技术将被用来研究气相中的活性中间产物，这些中间产物是通过电子撞击或热解以及随后的超音速自由喷射膨胀方法产生的。为了进一步了解它们的基态能级和分子结构，我们将测量单卤代硅烯、单卤化锗、硅亚甲基、锗亚甲基及其氢化类似物的波长分辨荧光光谱和受激发射泵浦光谱。我们将用量子拍频光谱来研究硅亚甲基和锗的系间交叉和内转化动力学。我们将搜索和研究以前未知的硅和锗的电子光谱，包括甲基硅烷、硅酮、硫代硅酮和碳化锗。被选择用于研究的物种在半导体生长过程中扮演着重要的角色，也是目前天体物理学的研究热点。这项工作的一个强烈动机是硅和锗化合物化学与它们的碳基类似物之间的差异，以及对涉及硅和锗多个键的分子的检测和表征的兴趣。含有硅和锗的不稳定化合物被认为在半导体生长过程中发挥着重要作用，但这些活性分子目前实际上很少被识别或表征。建立检测和表征化学气相沉积中涉及的活性中间分子的灵敏方法对于发展薄膜和纳米颗粒生产的预测能力非常重要。这一努力的结果有望为半导体加工技术提供有用的信息。

Dennis Clouthier of the University of Kentucky is supported by the Experimental Physical Chemistry Program to study the electronic spectra and excited state dynamics of a variety of group IVA silicon- and germanium-containing reactive intermediates. A variety of laser spectroscopic techniques will be employed to study reactive intermediates in the gas phase, generated using electron impact or pyrolysis and subsequent supersonic free jet expansion methods. Wavelength resolved fluorescence and stimulated emission pumping spectra of monohalosilylenes, monohalogermylenes, silylidene, germylidene, and their deuterated analogs will be measured in order to obtain further knowledge of their ground state energy levels and molecular structures. Intersystem crossing and internal conversion dynamics of silylidene and the germylidene will be examined by quantum beat spectroscopy. Previously unknown electronic spectra of silicon and germanium methylidyne, silanone, thiosilanone, and germanium carbide will be searched for and studied. The species chosen for study play a significant role in semiconductor growth processes, and are also of current interest in astrophysics. A strong motivation for this work is the difference between silicon and germanium compound chemistry and that of their carbon-based analogs, and interest in detection and characterization of molecules involving multiple bonds to silicon and germanium.Unstable chemical compounds that contain silicon and germanium are believed to play a significant role in semiconductor growth processes, but few of these reactive molecules have actually been identified or characterized at this time. Establishing sensitive methods for detecting and characterizing reactive intermediate molecules involved in chemical vapor deposition is important in order to develop predictive capabilities for the production of thin films and nanoparticles. Outcomes from this effort are expected to provide useful information for semiconductor processing technologies.