Acquisition of a Multi-Probe Scanning Tunneling Microscope with SEM for Student Training in Research

通过材料研究仪器项目和主要研究仪器项目的奖励，马里兰大学将能够获得一种组合式扫描探针/扫描电子显微镜。由于纳米器件的电子特性随结构的变化，该仪器将用于解决纳米电子学的关键问题。例如，在评估纳米器件的电接触、器件的结构缺陷、甚至热波动如何或是否会限制纳米器件的性能和可重复性方面，这个问题至关重要。这也是开发纳米结构应用的关键，这些纳米结构源于其内在特性：即，当器件特性随结构和/或局部环境的强烈变化是一种自然特征时，这些特性可以作为响应机制加以利用。在测量电子输运性质的同时对纳米结构的原子结构进行成像的技术将得到发展。这些实验将通过探测结构的动态变化（由温度、电场、电流和化学势驱动）对纳米器件电输运特性的影响，建立纳米器件结构与电子性能之间的相关性。从理论上研究纳米结构与电响应之间的关系。这种新型仪器，一种结合扫描探针/扫描电子显微镜的仪器，也将用于上述研究领域的研究生培训。随着材料尺寸接近纳米级，预计在材料结构中会出现重要的新技术特性。这样的小结构的位置，允许直接测量他们的性质是一个严重的技术挑战，因为是测量本身。这项来自材料研究仪器项目和主要研究仪器项目的奖励将帮助马里兰大学购买一种结合了两台显微镜和一个精细定位台的仪器。一台显微镜将用于定位小结构，扫描阶段将用于将小结构移动到第二台显微镜的测量范围内。第二台显微镜将是一台超高分辨率显微镜，具有对单个原子位置成像的能力。将进行实验，其中小结构中单个原子位置变化的影响与小结构的电学性质（例如携带电流的能力）相关。新仪器还将用于上述研究领域的研究生培训。

With this award from the Instrumentation for Materials Research program and the Major Research Instrumentation program, the University of Maryland will be able to acquire a combined scanning probe/scanning electron microscope. The instrument will be used to address critical issues of nano-electronics due to the variability of nano-device electronic properties with structure. This issue is critical, for instance, in assessing how or whether electrical contacts to nano-devices, structural defects in the devices, or even thermal fluctuations will limit nano-device performance and reproducibility. It is also key to developing applications of nano-structures that derive from their intrinsic properties: i.e. where strong variations of device properties with structure and/or local environment are a natural characteristic, these properties may be exploited as response mechanisms. Techniques to image the atomic structure of nanostructures while simultaneously measuring electronic transport properties will be developed. These experiments will establish the correlations between structure and the electronic properties of nanodevices, by probing the effects of dynamic changes in structure (driven by temperature, electric field, current and chemical potential) on the electrical transport properties of the nanodevices. The relationship between structure and the electrical response of nanostructures will also be investigated theoretically. The new instrument, a combined scanning probe/scanning electron microscope will also be used for graduate student training in the research areas described above.Important new technological properties are expected to occur in materials structures as their size approaches the nanoscale. Location of such small structures to allow the direct measurement of their properties is a serious technical challenge, as is the measurement itself. This award from the Instrumentation for Materials Research program and the Major Research Instrumentation program will help the University of Maryland with the purchase of an instrument that combines two microscopes and a fine positioning stage. One microscope will be used to locate small structures, and the scanning stage will be used to move the small structures into the measurement range of the second microscope. The second microscope will be an ultra-high resolution microscope with the capability of imaging the positions of individual atoms. Experiments will be performed in which the effect of changes in the positions of individual atoms in small structures are correlated with the electrical properties (e.g. the ability to carry electrical current) of the small structures. The new instrument will also be used for graduate student training in the research areas described above.