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

本课题主要研究含硅半导体薄膜热丝化学气相沉积（HWCVD）工艺中形成的气相反应中间体的动力学、结构和能量学。它还涉及应用气相研究的科学发现来优化薄膜形成过程。气相反应物质是HWCVD中膜生长前体的主要来源。它们在决定薄膜生长速率和薄膜性能方面尤为重要。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）和激光诱导电子冲击电离（LIEI），将与飞行时间质谱（TOF MS）结合使用，以确定反应物质，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，来表征激发态中性和基态阳离子的振动结构，并确定反应中间体的精确电离能。这项研究将导致对这些物种的高灵敏度和选择性诊断工具的发展。它还将提供反应中间体的基本性质，这些中间体很难获得，但在自由基-自由基和自由基-分子反应的研究中是无价的。最后，我们将采用各种表面诊断方法来检查在不同沉积条件下生产的薄膜的性能，以获得HWCVD设备的通用设计参数。总之，这项研究将有助于在分子水平上深入了解HWCVD过程中涉及的基本化学和物理。这些知识对于开发综合沉积模型至关重要，并为合理优化HWCVD中的薄膜形成提供重要指导，以获得工业应用中高质量的薄膜。

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.