Ballistic Electron Emission Spectroscopy of Heterostructures Using Metal and Degenerately-Doped Semiconductor Tips

9313610 Narayanamurti一种独特的变温、超高真空(UHV)兼容弹道电子发射显微镜(BEEM)仪器目前正在PI的实验室开发中。这一探索性的建议旨在为BEEM提供制作技巧，以便对量子半导体异质结构和超晶格进行光谱处理。适当制备、重掺杂的半导体尖端应该会导致一束尖锐聚焦的单能电子束或空穴注入所研究的样品中。使用Beem光谱进行变温UHV研究的能力可能导致观察到量子力学隧道效应和界面反射效应，局部确定掺杂密度，少数载流子平均自由程，以及单粒子电荷效应(库仑阻塞机制)，可能是第一次研究尺寸受限的pn结的离散光发射。这项技术的发展将对纳米线、量子点、共振隧道器件和窄禁带红外探测器等尺寸较小的系统的光谱学研究尤为重要。一种独特的变温、超高真空(UHV)兼容弹道电子发射显微镜(BEEM)仪器目前正在PI的实验室中开发。这一探索性建议旨在为BEEM制造探针，以便对复杂的半导体结构进行光谱分析。适当准备、重掺杂的半导体探测器应该会导致一束尖锐聚焦的单能电子束或空穴注入到所研究的样品中。使用Beem光谱学进行变温超高电压研究的能力将提供有价值的物理测量，并可能导致更好地理解所谓的量子点、半导体异质结构和超晶格中的电子态。很明显，随着半导体器件的特征尺寸接近纳米级，这样的研究变得越来越重要。***

9313610 Narayanamurti A unique variable temperature, ultra high vacuum (UHV) compatible Ballistic Electron Emission Microscope (BEEM) apparatus is currently under development in the PI's laboratory. This exploratory proposal is directed at fabricating tips for the BEEM to perform spectroscopy on quantum semiconductor heterostructures and superlattices. Properly prepared, heavily doped, semiconductor tips should cause a sharply focused and monoenergetic beam of electrons or holes to be injected into the sample under study. The ability to perform variable temperature UHV studies using BEEM spectroscopy could lead to the observation of quantum mechanical tunneling and interface reflection effects, local determination of dopant density, minority carrier mean free paths, and single particle charging effects (Coulomb blockade regime) with possibly the first studies of discrete light emission from the dimensionally confined pn junction. Development of this technique will be particularly important for the spectroscopic study of dimensionally small systems such as nano-scale wires, quantum dots, resonant tunneling devices and narrow bandgap infrared detectors. %%% A unique variable temperature, ultra high vacuum (UHV) compatible Ballistic Electron Emission Microscope (BEEM) apparatus is currently under development in the PI's laboratory. This exploratory proposal is directed at fabricating probes for the BEEM to perform spectroscopy on complex semiconductor structures. Properly prepared, heavily doped, semiconductor probes should cause a sharply focused and monoenergetic beam of electrons or holes to be injected into the sample under study. The ability to perform variable temperature UHV studies using BEEM spectroscopy would provide valuable physical measurements and could lead to a better understanding of the electronic states in so-called quantum dots and semiconductor heterostructures and superlattices. It is clear that such studies become increasingly important as characteristic dimensions of semiconductor devices approach the nano-meter scale regime. ***