Collaborative Research: Muonium Dynamics in Semiconductors

小行星9623823 本计画主要研究半导体中μ素缺陷中心的动力学性质。 当注入的正μ子捕获电子时，形成μ 鎓，并模仿难以直接研究的孤立氢杂质的行为。 Si中的μ介子数据显示 三种电荷状态和两种结构构型，沿着在这些状态之间有许多跃迁。 μ介子跃迁动力学模型 和状态稳定性在Si中被推广，并获得Ge，GaAs和其他III-V族材料的参数。 μ子自旋共振与能级交叉 共振光谱提供了状态识别和结构细节，而磁场和温度依赖性的去极化率 产生关于扩散的信息， 过渡动力学 类似氢中心的非常相似的动力学性质对于浅掺杂剂的氢钝化效率及其对半导体材料的器件相关电学和光学性质的影响至关重要。 这项研究利用了氢和μ 鎓（一种由电子与正μ子结合而成的原子，一种不稳定的粒子）之间的相似性，以获得有关氢在半导体中的行为的信息，这些信息无法通过直接研究获得。 在硅或砷化镓等半导体中所有常见的杂质中，氢具有最不寻常的特性。 氢并没有形成使电子学成为可能的施主或受主，而是移动到现有的电子学中。 捐助者 或受体， 中和 他们 因此，氢可以非常显著地 影响器件特性。 对氢杂质的直接研究有严重的局限性;然而，对μ 鎓的研究提供了类似的信息，并且对那些最难直接攻击的问题提供了最多的信息。 目前的项目扩展了成功的μ 鎓研究，以了解含氢设备中活跃的过程。 ***

9623823 Lichti This project is an investigation of the dynamic properties of muonium defect centers in semiconductors. Muonium is formed when an implanted positive muon captures an electron, and mimics the behavior of isolated hydrogen impurities which are difficult to study directly. Data on muonium in Si has revealed three charge states and two structural configurations, along with numerous transitions among these states. A model of the muonium transition dynamics and state stabilities in Si is being generalized, and parameters obtained for Ge, GaAs, and other III-V materials. Muon spin resonance and level-crossing resonance spectra provide state identifications and give structural details, while the magnetic-field and temperature dependences of depolarization rates yield information on diffusion and transition dynamics. Very similar dynamic properties of the analogous hydrogen centers are crucial to the efficiency of hydrogen passivation of shallow dopants and its effect on the device- related electrical and optical properties of a semiconductor material. %%% This research exploits the similarities between hydrogen and muonium (an atom consisting of an electron bound to a positive muon, an unstable particle) in order to obtain information about the behavior of hydrogen in semiconductors which cannot be obtained from direct studies. Of all of the common impurities in semiconductors such as silicon or gallium arsenide, hydrogen has the most unusual properties. Rather than forming the donors or acceptors which make semiconductor-based electronics possible, hydrogen moves to existing donors or acceptors and neutralizes them. Consequently hydrogen can very substantially influence device characteristics. Direct investigation of hydrogen impurities has severe limitations; however, muonium studies supply similar information and have been most informative about those questions which are hardest to attack directly. The current project extends successful muonium studies to obtain an understanding of processes active in devices containing hydrogen. ***