Hot Wire Chemical Vapor Deposition Chemistry in the Gas Phase and on Surfaces

气相和表面上的热丝化学气相沉积化学

• 批准号: RGPIN-2014-04966
• 负责人: Shi, Yujun
• 金额: $ 3.13万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=665052
• 关键词: Hot; Wire; Chemical; Vapor; Deposition

The proposed research focuses on the gas-phase reaction chemistry and kinetics involved in the growth of silicon carbide and nitride thin films using hot wire chemical vapor deposition (HWCVD), and involves characterizing the structural and energetic properties of radical intermediates, and understanding the chemical processes taking place on the metal wire and substrate surfaces. HWCVD has been widely used to produce Si-based thin films, diamond coatings, nanoparticles and organic polymer coatings. Silicon carbides are excellent candidates for blue light-emitting diodes (LEDs) and wide bandgap window materials in solar cells, while silicon nitrides can be used as passivation layers in thin film transistors, anti-reflection coatings and diffusion barriers in solar cells. In the proposed research, laser ionization mass spectrometry, equipped with complimentary "soft" single photon vacuum UV laser ionization and efficient laser-induced electron ionization methods, will be used as a powerful diagnostic tool for the detection of gas-phase chemical species. These approaches, supported by isotope labeling, chemical trapping and ab initio calculations, will help unravel the complex reaction chemistry in the gas phase that is responsible for the formation of gas-phase thin film growth precursors. The structures and energetic properties of important radical species will be investigated using resonance enhanced multiphoton ionization (REMPI) spectroscopy combined with the techniques of high-voltage pulsed electric discharge and pulsed laser ablation. Highly sensitive and selective detection methods for the hard-to-isolate radical species will be developed from these studies. Our studies of the surface chemistry in HWCVD will be centered on metal alloy formation on the hot filament and Si-based thin film production on the substrate. Metal filaments are essential in HWCVD as they serve as catalysts to decompose source gases to form reactive species which initiates the gas-phase reaction chemistry. Exposure of metal filaments to the gas-phase reactive species leads to the formation of metal silicides and carbides. These resultant alloys cause the filament to age and affects the deposited film properties. We will systematically study the silicide and carbide formation on the metal wire upon exposure to various organosilicon source gases important for silicon carbide and nitride film growth. This will help solve the problem of filament aging and allow the deposition process to be controlled. Finally, characterization of the structural and optical properties of the ultimate Si-based thin film materials produced under various growth conditions will be correlated to the scientific findings from the gas-phase reaction chemistry and filament alloying. Overall, the proposed research will advance our current understanding of HWCVD chemistry and contribute to a rational improvement of the HWCVD process that will lead to superior-quality thin films for industrial applications. It will benefit greatly the industrial areas of semiconductors, alternative energy sources and microelectronics in Canada.

拟议的研究着重于使用热线化学蒸气沉积（HWCVD）（HWCVD）的气相反应化学和动力学，涉及碳化硅和氮化物薄膜的生长，并涉及表征自由基中间体的结构和能量性能，并了解化学过程在金属丝线上使用的化学过程。 HWCVD已被广泛用于生产基于SI的薄膜，钻石涂料，纳米颗粒和有机聚合物涂层。硅碳化物是蓝色发光二极管（LED）和太阳能电池中宽带的窗户材料的出色候选物，而硝酸硅可以用作薄膜晶体管，抗反射涂层和太阳能电池中的膨胀屏障的钝化层。在拟议的研究中，配备免费“软”单光子真空紫外线激光电离和有效激光诱导的电子电离方法的激光电离质谱法将用作检测气体化学物种的强大诊断工具。这些方法由同位素标记，化学诱捕和从头算计算支持，将有助于在气相中揭示复杂的反应化学，从而导致气相薄膜生长前体的形成。将使用共振增强的多光子电离（REMPI）光谱结合了高压脉冲电气排放和脉冲激光消融的技术，将研究重要自由基物种的结构和能量性能。这些研究将开发针对难以隔离的自由基物种的高度敏感和选择性检测方法。我们对HWCVD中表面化学的研究将集中在基板上的热丝和基于Si的薄膜生产的金属合金形成上。金属丝在HWCVD中至关重要，因为它们是分解源气体以形成反应性物种的催化剂，从而启动气相反应化学。金属丝暴露于气相反应性物种会导致金属硅和碳化物的形成。这些合成的合金导致细丝的年龄，并影响沉积的膜特性。我们将系统地研究金属线上的硅化硅和碳化物形成，以暴露于各种有机硅源气体中，对于碳化硅和氮化物膜的生长很重要。这将有助于解决细丝衰老的问题，并允许控制沉积过程。最后，在各种生长条件下生产的最终Si基薄膜材料的结构和光学特性的表征将与气相反应化学和丝质合金的科学发现相关。总体而言，拟议的研究将提高我们当前对HWCVD化学的理解，并有助于对HWCVD过程的合理改进，这将导致用于工业应用的优质薄膜。它将在加拿大的半导体，替代能源和微电子学的工业区域受益。