MRI/RUI: High Sensitivity Profiling of Hydrogen and Nitrogen Using Nuclear Reaction Analysis

MRI/RUI：利用核反应分析对氢和氮进行高灵敏度分析

• 批准号: 0216571
• 负责人: Daniel Marble
• 金额: $ 13.13万
• 依托单位: Tarleton State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-01 至 2004-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0216571&HistoricalAwards=false
• 关键词: MRI; RUI; Sensitivity; Profiling; Hydrogen

This Major Research Instrumentation RUI award is for the development and construction of an improved Nuclear Reaction Analysis (NRA) detection system based upon the Alabama A&M coincidence scheme, but with one to two orders of magnitude improvement in the signal-to-noise ratio. Previous results indicate that by modifying the detector geometry and materials, a larger, more efficient detector is possible without increasing the background signal. By using sample cooling and beam rastering, this larger detector will be able to routinely profile hydrogen in semiconductors with a sensitivity of one part-per-million and a surface depth resolution of five nanometers while remaining compatible with existing IBA facility requirements. The development of this detector would likely increase the use of NRA in the materials characterization community since it could be easily added to any existing IBA facility with minimal cost. This would allow companies and universities to perform hydrogen profiling by NRA and to use NRA for calibrating other IBA techniques including SIMS. Finally, the detector's ability to dramatically reduce all background sources including competing nuclear reactions without the reduction in efficiency of a germanium detector should open up new opportunities for profiling other light elements including nitrogen, boron, and carbon with greatly improved sensitivities.Light trace elements are known to have dramatic effects on the electrical, chemical and mechanical properties of many types of materials in even minute quantities. NRA is a powerful ion beam technique for quantitatively profiling light impurities in materials with excellent depth resolution. NRA has previously been used to profile a wide range of trace elements including H, B, C, N, and F in problems ranging from hydrogen embrittlement of metals to the dating of arrowheads. Potentially important applications of NRA include passivation studies of SiO2/SiC and SiO2/Si interfaces using hydrogen or nitrogen and the profiling of carbon and boron in metals to test predictions of computer simulations. Presently, few electronic companies or universities have NRA capability due to the technical difficulties inherent in obtaining high sensitivity.

这一重大研究仪器RUI奖是为了奖励基于阿拉巴马州A&M符合计划的改进的核反应分析(NRA)探测系统的开发和建设，但在信噪比方面有一到两个数量级的改进。以前的结果表明，通过改变探测器的几何形状和材料，可以在不增加背景信号的情况下获得更大、更有效的探测器。通过使用样品冷却和光束光栅化，这种更大的探测器将能够以百万分之一的灵敏度和5纳米的表面深度分辨率常规地分析半导体中的氢，同时保持与IBA现有设施的要求兼容。这种探测器的开发可能会增加NRA在材料表征领域的使用，因为它可以很容易地添加到任何现有的IBA设施中，成本最低。这将允许公司和大学通过NRA进行氢气剖析，并使用NRA校准包括SIMS在内的其他IBA技术。最后，该探测器能够在不降低锗探测器效率的情况下，大幅减少包括竞争核反应在内的所有背景源，这将为分析其他轻元素，包括氮、硼和碳开辟了新的机会，灵敏度大大提高。众所周知，光痕量元素即使在极少量的情况下，也会对许多类型材料的电、化学和机械性能产生巨大影响。NRA是一种强大的离子束技术，用于定量分析材料中的轻杂质，具有极高的深度分辨率。在从金属氢脆到箭头测年的各种问题中，NRA以前曾被用来分析包括H、B、C、N和F在内的各种微量元素。NRA的潜在重要应用包括使用氢或氮对SiO_2/SiC和SiO_2/Si界面进行钝化研究，以及用来测试计算机模拟预测的金属中碳和硼的分布。目前，由于获得高灵敏度所固有的技术困难，很少有电子公司或大学具有NRA能力。