Chemical Vapor Deposition of Metallic Films at Low Temperatures: Precursor Synthesis and Hydrogen-Assisted Reaction Chemistry

该项目旨在更好地了解薄膜的生长/沉积，实现金属二硼化物薄膜化学气相沉积的新途径，以及铜，钽和其他金属薄膜的原子层沉积（ALD），所有这些都是在低衬底温度下进行的。科学目标是利用原位光学、质量和电子能谱来理解薄膜形成的化学过程。该方法包括四个平行的努力：1)利用氢等离子体增强原子层沉积法合成新的前体分子，用于Cu， Ta和其他金属的生长，以及利用氢等离子体增强CVD法生长ZrB2， MgB2和其他二硼化物合金。2)利用新前驱体的膜生长策略将被开发：氢等离子体增强ALD沉积Cu和Ta，热CVD（化学气相沉积）沉积CrB2，氢等离子体增强CVD沉积MgB2。CrB2和MgB2的生长将使用pi最近发现的前体Cr(B3H8) 2和Mg(B3H8) 2进行研究。探讨了ZrB2和CrB2单晶薄膜在Si（111）上的异质外延生长和ZrB2或CrB2上的MgB2薄膜的异质外延生长，以及以多壁C纳米管为模板合成ZrB2或CrB2纳米管。3)薄膜形成途径将使用原位光谱分析，以确定控制ALD和CVD过程的机制。表面反应将使用下游质谱、反射红外吸收、石英晶体微天平、程序升温解吸和俄歇电子能谱进行分析。在适用的情况下，将使用同位素标记（D代表H）。将研究静态（生长后）和动态（生长期间）表面，包括时间调制通量的使用。在沟槽基底上进行保角覆盖实验，提取前驱体的表面反应概率，作为温度和原子氢同步通量的函数。成核，组成，和表面粗糙度将研究使用实时光谱椭偏仪。4)薄膜的结构和性能将被评估，包括晶体结构、电导率和作为杂质扩散屏障的性能。沉积，退火和分析由Cu/Ta/Si或Cu/CrB2/Si组成的结构，以确定Cu在Si中的扩散。本项目研究与电子/光子材料相关的基础材料科学和化学研究问题，具有技术相关性，并强调研究与教育的整合。该项目每年将支持4名研究生和1-2名本科生进行暑期项目或高级论文。UIUC的SURGE（工程领域代表性不足群体的支持）和WISE（科学和工程领域的女性）项目将被用来帮助扩大代表性不足群体的参与。研究成果将通过在国际会议上的发言和在科学期刊上发表来广泛传播。工业微电子组织，如IBM，英特尔，Novellus或应用材料，将被访问，介绍和讨论项目成果，以加强大学/行业的互动。该项目由MPS/DMR和MPS/CHE部门共同支持

This project aims for greater understanding of thin film growth/deposition, achievement of new routes to chemical vapor deposition of metal diboride thin films, and atomic layer deposition (ALD) of copper, tantalum, and other metallic films, all at low substrate temperatures. The scientific goal is to understand the chemistry of film formation using in situ optical, mass, and electron spectroscopies. The approach involves four parallel efforts: 1) New precursor molecules will be synthesized that are designed for the growth of Cu, Ta, and other metals using hydrogen plasma enhanced atomic layer deposition, and for the growth of ZrB2, MgB2, and other diboride alloys using hydrogen plasma enhanced CVD. 2) Film growth strategies using the new precursors will be developed: deposition of Cu and Ta by hydrogen plasma enhanced ALD, CrB2 by thermal CVD (chemical vapor deposition), and MgB2 by hydrogen plasma enhanced CVD. CrB2 and MgB2 growth will be investigated using precursors Cr(B3H8) 2 and Mg(B3H8) 2 recently discovered by the PIs. Heteroepitaxial growth of single crystal films of ZrB2 and CrB2 on Si(111) and MgB2 films on ZrB2 or CrB2 will be explored, as well as the synthesis of ZrB2 or CrB2 nanotubes using multi-walled C nanotubes as a template. 3) Film formation pathways will be analyzed using in situ spectroscopies to determine the mechanisms that govern ALD and CVD processes. Surface reactions will be analyzed using downstream mass spectroscopy, reflection IR absorption, quartz crystal microbalance, temperature programmed desorption, and Auger electron spectroscopy. Where applicable, isotopic labeling (D for H) will be utilized. Both static (post-growth) and dynamic (during growth) surfaces will be studied, including the use of time-modulated fluxes. Conformal coverage experiments on trench substrates will be used to extract the surface reaction probability of precursors, as a function of temperature and the concurrent flux of atomic hydrogen. Nucleation, composition, and surface roughness will be studied using real time spectroscopic ellipsometry. 4) Film structure and properties will be evaluated, including crystal structure, electrical conductivity, and performance as impurity diffusion barriers. Deposition, annealing, and analysis of structures consisting of Cu/Ta/Si or Cu/CrB2/Si will be carried out to determine Cu in-diffusion into Si. %%% The project addresses fundamental materials science and chemistry research issues associated with electronic/photonic materials having technological relevance, and emphasizes the integration of research and education. The project will support four graduate students, and 1-2 undergraduates per year conducting summer projects or senior theses. The UIUC SURGE (Support of Under-represented Groups in Engineering) and WISE (Women in Science and Engineering) programs will be utilized to assist with broadening participation by under-represented groups. Research results will be broadly disseminated by presentations at international conferences and by publication in scientific journals. Industrial microelectronics organizations, e.g., IBM, Intel, Novellus, or Applied Materials, will be visited to present and discuss project results to enhance university/industry interactions. The project is co-supported by the MPS/DMR and MPS/CHE Divisions.***