Low-Temperature CVD for Microelectronics: Utilizing Surface Reactions to Afford ALD-Like Conformality

微电子领域的低温 CVD：利用表面反应实现类似 ALD 的共形性

• 批准号: 1005715
• 负责人: John Abelson
• 金额: $ 45.67万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-01 至 2013-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1005715&HistoricalAwards=false
• 关键词: Low; Temperature; CVD; Microelectronics; Utilizing

Technical: The proposed work will develop methods of low temperature chemical vapor deposition (CVD) to afford uniform, smooth, and pinhole free thin films on substrates that have high aspect-ratio openings such as deep trenches and vias. Such films are required for a wide variety of advanced technologies, e.g., diffusion barriers associated with copper metallization in integrated circuits. The CVD method can also completely fill these features at reasonable rates. Examples to date include the coating and filling of high aspect ratio (30:1) vias, 100 nm in diameter, with HfB2 or MgO films.Three experimental approaches are used to achieve excellent coating properties. (i) Unique CVD precursor molecules with high vapor pressure produce a site-blocking effect on the film growth surface, such that the surface reactivity is low but the growth rate is acceptable. (ii) Inhibitor species are added to the growth process to modify the surface reactivity: H atoms impinge on, and bind strongly to the most exposed (upper) surfaces and lead to bottom-up film growth; molecular species such as NH3 or dme uniformly lower the growth rate such that a ?non conformal? precursor will afford a highly conformal film. (iii) Inhibitor species are used to enhance the density of nuclei on a substrate by reducing the growth rate of the first-formed nuclei with respect to the rate at which new nuclei form. This has the effect of greatly smoothing films of few-nm thickness, and of eliminating pinholes. The approaches have transformative potential in the field of thin film growth.This research employs surface science techniques and kinetic modeling to obtain a mechanistic understanding of the surface reactions involved in highly conformal chemical vapor deposition of thin films. That intellectual synthesis across disciplines ? surface physics, surface chemistry, and thin film materials science provides enabling scientific knowledge to guide further development of conformal CVD. For example, it affords quantitative metrics for the necessary properties and behavior of precursor molecules and inhibitor species.Non-technical: The project addresses basic research issues in a topical area of materials science with technological relevance, and is expected to provide unique opportunities for graduate and undergraduate training in an interdisciplinary field. This research project is also expected to have broader impacts through the training of scientists in this research field and through the wide dissemination of the findings of this research through publications. The PI will mentor a REU student and one or two undergraduate senior theses in the group. Graduate students and undergraduates from under-represented groups are recruited via the University of Illinois programs SURGE (Support ofUnder-Represented Groups in Engineering) and WISE (Women in Science and Engineering). One woman Ph.D. student is associated with this project at the time of writing. Periodic news stories also report the developments and cite the crucial role of the National Science Foundation in the process of discovery.

技术支持：拟议的工作将开发低温化学气相沉积（CVD）方法，以在具有高深宽比开口（如深沟槽和通孔）的基板上提供均匀、光滑和无针孔的薄膜。这种膜是多种先进技术所需要的，例如，与集成电路中的铜金属化相关的扩散阻挡层。CVD方法也可以以合理的速率完全填充这些特征。迄今为止的例子包括用HfB 2或MgO膜涂覆和填充直径为100 nm的高纵横比（30：1）的通孔。(i)具有高蒸气压的独特CVD前体分子在膜生长表面上产生位点阻断效应，使得表面反应性低但生长速率是可接受的。(ii)抑制剂物种被添加到生长过程中，以修改表面反应性：H原子冲击，并强烈结合到最暴露的（上）表面，并导致自下而上的薄膜生长;分子物种，如NH3或DME均匀地降低生长速率，使？非共形？前体将提供高度共形的膜。(iii)抑制剂物质用于通过相对于新的核形成的速率降低第一形成的核的生长速率来提高基底上的核密度。这具有使几纳米厚度的膜非常平滑和消除针孔的效果。该方法在薄膜生长领域具有变革性的潜力。本研究采用表面科学技术和动力学建模，以获得高度共形化学气相沉积薄膜的表面反应的机理理解。跨学科的智力综合？表面物理学、表面化学和薄膜材料科学提供了使能的科学知识来指导共形CVD的进一步发展。例如，它提供了必要的前体分子和抑制剂种类的性质和行为的定量指标。非技术性：该项目解决了材料科学与技术相关的主题领域的基础研究问题，预计将为跨学科领域的研究生和本科生培训提供独特的机会。通过培训这一研究领域的科学家和通过出版物广泛传播这一研究的结果，这一研究项目预计也将产生更广泛的影响。PI将指导REU学生和一个或两个本科毕业论文组。来自代表性不足群体的研究生和本科生通过伊利诺伊大学的SURGE（支持工程领域代表性不足的群体）和WISE（科学和工程领域的女性）项目招募。一名女博士在撰写本文时，学生与本项目相关。定期的新闻报道也报道了这些进展，并引用了国家科学基金会在发现过程中的关键作用。