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

该研究项目涉及含硅半导体薄膜热线化学气相沉积(HWCVD)过程中形成的气相反应中间体的动力学、结构和能量学研究。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成膜前驱体的主要来源。它们在确定薄膜生长速度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)，将与飞行时间质谱仪(TOF MS)一起使用，以识别反应物种并了解为薄膜生长产生前体物种的化学动力学。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，来表征被激发的中性离子和基态阳离子的振荡子结构，并确定反应中间体的准确电离能。这项研究将导致开发针对这些物种的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，这些中间体极难获得，但在研究自由基-自由基和自由基-分子反应中具有无价价值。最后，我们将使用各种表面诊断方法来检测在不同沉积条件下制备的薄膜的性能，以获得HWCVD设备的总体设计参数。总之，这项研究将有助于深入了解HWCVD过程中涉及的基础化学和物理。这些知识对于开发一个全面的沉积模型和合理优化HWCVD成膜提供重要的指导，以获得用于工业应用的高质量薄膜。

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.