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）是一种最有前途的技术，用于生产器件级含硅薄膜，广泛应用于太阳能电池、半导体工业和生物技术等领域。提出的研究计划旨在提供对碳化硅和氮化硅合金材料HWCVD的基本化学和物理的分子水平的理解，并应用这些知识来优化薄膜的形成过程。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）和激光诱导电子冲击电离（LIEI），结合飞行时间（TOF）质谱（MS）来确定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。这将有助于为这些活性物质开发高灵敏度和选择性的诊断方法，并有助于理解生长机制，因为这些气体团簇可以被视为碳和氮原子与表面硅位点相互作用的原型。我们还将描述在不同源气体和不同沉积参数下制备的碳化硅和氮化硅薄膜的结构和成分变化。这些结果将与我们使用激光电离质谱和光谱技术研究气相化学的结果相关联，以获得气相和衬底表面生长过程的完整图像。本研究将为高效、合理地优化HWCVD成膜工艺以获得高质量的含硅薄膜提供重要指导。

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.