Chemical Vapor Deposition of Si-containing Thin Films and Si Nanostructures: From a molecular-level understanding to applications

含硅薄膜和硅纳米结构的化学气相沉积：从分子水平的理解到应用

• 批准号: RGPIN-2019-04845
• 负责人: Shi, Yujun
• 金额: $ 2.62万
• 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: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=748090
• 关键词: Chemical; Vapor; Deposition; Si; containing

The technique of hot wire chemical vapor deposition (HWCVD) involves catalytic dissociation of source gases to form radicals on a heated metal wire and subsequent radical-radical and radical-molecule reactions in the gas phase to produce film growth precursors that react with the substrate, leading to thin film formation. These gas-phase growth precursors strongly affect the growth rate and properties of the deposited films. A lot of industrial efforts have been made to find the golden recipe for optimal and desired properties of final products, most often by trial-and-error methods. We have adopted a unique approach trying to understand the chemical and physical processes underpinning the thin film formation using HWCVD. For this, the technically demanding laser ionization mass spectrometric (LIMS) techniques will be employed as powerful diagnostic tools to identify the gas-phase film growth precursors and to study the chemical kinetics governing the production of these precursor species in the HWCVD processes of silicon nitride (SiNx) and carbonitride (SiCyNz) thin films with different source gas systems. This work on the underlying chemistry will help develop novel, environmentally benign precursors and rational improvement methods to find the best recipe in HWCVD of SiNx/SiCyNz films for industrial applications in optoelectronics and microelectronics. We also aim at a fundamental understanding of the chemical reactions responsible for the formation of Si atoms in the CVD growth of Si nanowires (SiNWs) using the powerful LIMS diagnostic tools. This could help fill in some gaps in the current CVD growth models for SiNWs. Among a wide spectrum of applications of SiNWs, we focus on their use as anode materials in lithium ion batteries (LIB). Si is one of the most promising LIB anode materials due to its highest known theoretical charge capacity. To tackle the key challenge in using Si as LIB anode, which is the capacity fading due to the large volume expansion upon insertion and extraction of Li, we propose to fabricate an ordered array of SiNWs with pre-defined spacing and size by using organized metal nanoparticle arrays (MNAs) as catalysts in the CVD growth. The controlled formation of MNAs will be accomplished by the novel technique of pulsed laser-induced dewetting (PLiD) of metal films on pre-patterned substrates prepared by electrochemical methods. The developed protocol could provide an alternative method to the expensive lithography-based methods. Finally, the developed PLiD methods will be explored for the formation of Pt-based bimetallic MNAs as electrocatalysts for fuel cell reactions to limit the amount of expensive Pt and to obtain new catalysts with enhanced selectivity, activity and stability. Overall, the proposed research will advance our current knowledge of the two CVD processes - HWCVD of SiNx/SiCyNz films and CVD growth of SiNWs. It will also contribute to the development of LIB anode materials and fuel cell catalysts.

热线化学蒸气沉积（HWCVD）的技术涉及源气体的催化解离，以在加热的金属电线上形成自由基，并在气相中产生自由基 - 自由基和自由基 - 分子反应，以产生与底物反应的膜生长前体，从而导致薄膜形成。这些气相生长前体强烈影响沉积膜的生长速率和特性。已经做出了许多工业努力，以找到最终产品的最佳和期望特性的黄金配方，通常是通过反复试验的方法。我们采用了一种独特的方法，试图了解使用HWCVD薄膜形成的化学和物理过程。为此，技术苛刻的激光电离质谱（LIM）技术将被用作强大的诊断工具，以识别气相膜的生长前体，并研究控制这些前体物种在HWCVD过程中的化学动力学，以硅烷（Sinx）和CarbonItride（Sicynz）（Sicynz）（Sicynz）（Sycyride）（Sicynz）（Sicynz）（Sycyride）（Sycyride sycyride sycyride）。关于基础化学的这项工作将有助于开发新颖的环境良性前体和合理的改进方法，以找到Sinx/Sicynz膜中最佳食谱，用于光电和微电子学中的工业应用。我们还旨在对使用强大的LIMS诊断工具在CVD生长（SINWS）中形成Si原子的化学反应的基本理解。这可能有助于填补SINW当前CVD增长模型的一些空白。在SINW的广泛应用中，我们专注于它们在锂离子电池（LIB）中用作阳极材料。由于其最高的理论电荷能力，SI是最有前途的Lib阳极材料之一。为了应对使用SI作为Lib阳极的关键挑战，这是由于LI插入和提取时的容量扩大而导致的容量褪色，我们建议通过使用有组织的金属纳米颗粒阵列（MNAS）催化CVD增长来制造具有预定的间距和大小的有序的SINW阵列。 MNA的受控形成将通过通过电化学方法制备的预图案底物上的金属膜的脉冲激光诱导的脱水（PLID）来完成。开发的协议可以为基于昂贵的光刻方法提供替代方法。最后，将探索开发的PLID方法，以形成基于PT的双金属MNA作为燃料电池反应的电催化剂，以限制昂贵的PT量，并获得具有增强的选择性，活性和稳定性的新催化剂。总体而言，拟议的研究将促进我们目前对两个CVD过程的了解-Sinx/Sicynz膜的HWCVD和SINW的CVD增长。它还将有助于开发自由阳极材料和燃料电池催化剂。