NMR Studies of Defects in Semiconductors

这项研究涉及应用核磁共振 共振（NMR）的研究中的特定类别的缺陷， 半导体材料。氢络合物的研究 掺杂剂将与工业界合作进行， 合作伙伴关注的影响，氢引入到 在处理和器件制造期间的半导体。的 该计划将侧重于三个具体目标：位置和 砷化镓中氢与掺杂剂络合的动力学 硅半导体将使用双共振测定 技术来选择性地探测复合物。确定和 热产生的顺磁缺陷的表征 砷化镓和相关材料将在 原位高温NMR技术。铟占据的位置 杂质及空位-杂质复合物的表征 II-VI材料，包括结果与 同时研究这些缺陷使用扰动角 相关技术，将进行研究。 %%% 电子半导体材料的性能 器件主要受杂质和晶体的影响 缺陷 这些影响可能是建设性的，例如 “掺杂”，其中可以使用特定的杂质来获得所需的杂质。 电性能另一方面， 从有机材料向半导体中引入氢 在材料加工过程中使用的可能是非常有害的。氢 可以“钝化”或中和掺杂剂杂质， 不带电 非预期和表征不良的缺陷 在半导体材料中导致不良产率和器件 失败利用众所周知的缺陷， 开发先进半导体材料的潜力， 改进的特性。核磁共振（NMR）将是 用于表征的位置和运动特性 各种技术材料中原子尺度上的缺陷 重要性包括硅、砷化镓和镉 碲化物。该技术具有高度选择性，能够 探测特定位置的单个化学物质， 晶体半导体核磁共振技术的最新进展 高磁场超导磁体的使用使得 研究某些浓度低至 百万分之几十

This research involves the application of nuclear magnetic resonance (NMR) to the study of specific classes of defects in semiconducting materials. Studies of hydrogen complexed with dopants will be carried out in collaboration with industrial partners concerned about the effects of hydrogen introduced into semiconductors during processing and device fabrication. The program will focus on three specific goals: The location and dynamics of hydrogen complexed with dopants in gallium arsenide and silicon semiconductors will be determined using double resonance techniques to selectively probe the complex. The identification and characterization of thermally generated paramagnetic defects in gallium arsenide and related materials will be undertaken using in situ high temperature NMR techniques. The sites occupied by indium impurities and characterization of vacancy-impurity complexes in II-VI materials, including correlation of the results with concurrent studies of these defects using perturbed angular correlation techniques, will be studied. %%% The performance of semiconducting materials used in electronic devices is dominated by the effects of impurities and crystalline defects. These effects can be constructive, as in the case of "doping," where specific impurities can be used to obtain desired electrical properties. On the other hand, the incidental introduction of hydrogen into semiconductors from organic materials used during material processing can be highly deleterious. Hydrogen can "passivate," or neutralize dopant impurities, rendering them electrically inactive. Undesired and poorly characterized defects in semiconducting materials lead to poor yields and device failures. Exploitation of well-understood defects holds the potential for development of advanced semiconducting materials with improved characteristics. Nuclear magnetic resonance (NMR) will be used to characterize the location and motional properties of defects on the atomic scale in various materials of technological importance including silicon, gallium arsenide, and cadmium telluride. This technique is highly selective and is capable of probing individual chemical species in specific locations in a crystalline semiconductor. Recent improvements in NMR techniques and the use of high field superconducting magnets make it possible to investigate certain defect species at concentrations as low as a few tens of parts per million.