A molecular-level investigation of the hot-wire chemical vapor deposition chemistry of si-containing thin films

热线化学气相沉积（HWCVD）是用于制备器件质量的含硅薄膜的最有前途的技术之一，所述器件质量的含硅薄膜在太阳能电池、半导体工业和生物技术中的各种应用中是所需的。拟议的研究计划旨在提供对碳化硅和氮化硅合金材料的HWCVD中的基本化学和物理的分子水平的理解，并将知识应用于薄膜形成过程的优化。我们将使用两种基于激光的电离方法，即，真空紫外（VUV）单光子电离（SPI）和激光诱导电子碰撞电离（LIEI），结合飞行时间（TOF）质谱（MS）来识别气相膜生长前体的性质并确定控制其形成的化学动力学。激光光谱技术，包括共振增强多光子电离（REMPI）和零动能（ZEKE）光电子/质量分析阈值电离（MATI），将用于表征气态碳化硅（SixCy）和氮化硅（SinNm）团簇的结构，键合和能量特性。这将有助于开发高灵敏度和选择性的诊断方法，这些反应物种，并有助于生长机制的理解，因为这些气体团簇可以被视为原型的碳和氮原子与硅表面的网站的相互作用。我们还将表征使用不同的源气体和各种沉积参数制备的碳化硅和氮化硅薄膜的结构和成分的变化。结果将与我们的气相化学研究，使用激光电离质谱和光谱技术的生长过程的完整图片，无论是在气相和基板表面上的那些。研究结果对高效合理地优化HWCVD成膜工艺，获得工业应用的上级质量含硅薄膜具有重要的指导意义。

Hot-wire chemical vapor deposition (HWCVD) is one of the most promising techniques for producing device-quality silicon-containing thin films needed for a wide variety of applications in solar cells, semiconductor industry and biotechnology. The proposed research program aims at providing a molecular-level understanding of the fundamental chemistry and physics in HWCVD of silicon carbide and silicon nitride alloy materials, and applying the knowledge for an optimization of film formation processes. We will use two laser-based ionization methods, i.e., vacuum ultraviolet (VUV) single-photon ionization (SPI) and laser induced electron impact ionization (LIEI), coupled with time-of-flight (TOF) mass spectrometry (MS) to identify the nature of the gas-phase film growth precursors and to determine the chemical kinetics that govern their formation. Laser spectroscopic techniques, including resonance-enhanced multiphoton ionization (REMPI) and zero kinetic energy (ZEKE) photoelectron/mass analyzed threshold ionization (MATI), will be used to characterize the structure, bonding and energetic properties of gaseous silicon carbide (SixCy) and silicon nitride (SinNm) clusters. This will help develop highly sensitive and selective diagnostic method for these reactive species and contribute to the understanding of growth mechanisms since these gaseous clusters can be viewed as prototypes for the interactions of carbon and nitrogen atoms with silicon sites at surfaces. We will also characterize the structural and compositional changes of the silicon carbide and silicon nitride thin films prepared using different source gases and various deposition parameters. The results will be correlated with those from our studies of gas-phase chemistry using laser ionization mass spectrometric and spectroscopic techniques for a complete picture of the growth processes, both in the gas-phase and on the substrate surfaces. The proposed research will provide importance guidance towards an efficient and rational optimization of film formation in HWCVD to obtain superior quality silicon-conatining thin films for industrial applications.