Structures, kinetics, and energetics of reactive intermediates in hot-wire chemical vapor deposition of Si-containing films

该研究计划涉及的动力学，结构和热力学的研究气相反应中间体形成的热线化学气相沉积（HWCVD）过程中的含硅半导体薄膜。它还涉及应用气相研究的科学发现来优化成膜过程。气相反应物种是HWCVD中薄膜生长前驱物的主要来源。它们在确定薄膜生长速率和薄膜性能方面特别重要。在我们的研究中，基于激光的电离技术，如真空紫外激光单光子电离（SPI）和激光诱导电子碰撞电离（LIEI），将与飞行时间质谱（TOF MS）串联使用，以确定活性物质，并了解产生薄膜生长前体物质的化学动力学。我们还将利用几种激光光谱技术，包括共振增强多光子电离（REMPI），零动能（ZEKE）光电子/质量分析阈值电离（MATI）光谱，来表征激发的中性和基态阳离子的旋转振动结构，并确定准确的活性中间体的电离能。这项研究将导致为这些物种开发高度敏感和选择性的诊断工具。它还将提供活性中间体的基本性质，这是非常难以获得的，但在自由基-自由基和自由基-分子反应的研究中是非常宝贵的。最后，我们将采用各种表面诊断方法来检查在各种沉积条件下产生的薄膜的性质，以获得HWCVD设备的一般设计参数。总之，这项研究将有助于深入分子水平的理解HWCVD过程中涉及的基本化学和物理。这方面的知识是必不可少的，以开发一个全面的沉积模型，并提供重要的指导，合理优化薄膜形成在HWCVD获得上级质量的薄膜的工业应用。

The research program involves the studies of kinetics, structures and energetics of gas-phase reactive intermediates formed in the hot-wire chemical vapor deposition (HWCVD) process of Si-containing semiconductor thin films. It also involves the application of the scientific findings from gas phase studies to optimize the film formation process. The gas phase reactive species are the major source of film growth precursors in HWCVD. They are particularly important in determining the film growth rate and film properties. In our research, laser-based ionization techniques, such as vacuum ultraviolet laser single photon ionization (SPI) and laser-induced electron impact ionization (LIEI), will be used in tandem with time-of-flight mass spectrometry (TOF MS) to identify the reactive species and to understand the chemical kinetics that produce precursor species for film growth. We will also utilize several laser spectroscopic techniques, including resonance-enhanced multiphoton ionization (REMPI), zero kinetic energy (ZEKE) photoelectron / mass analyzed threshold ionization (MATI) spectroscopy, to characterize the rovibronic structures of the excited neutrals and ground state cations, and to determine the accurate ionization energies of the reactive intermediates. The research will lead to the development of highly sensitive and selective diagnostic tools for these species. It will also provide fundamental properties of the reactive intermediates, which are extremely difficult to obtain, yet invaluable in the study of radical-radical and radical-molecule reactions. Finally, we will employ various surface diagnostic methods to examine the properties of the thin films produced at various deposition conditions to achieve general design parameters for HWCVD equipment. Together, this research will contribute to a deep molecular level understanding of the fundamental chemistry and physics involved in the HWCVD processes. This knowledge is essential to develop a comprehensive deposition model and to provide important guidance toward rational optimization of film formation in HWCVD to obtain superior quality films for industrial applications.