\NER: Coaxial Tip Piezoresistive Cantilever Probes for High-Resolution Scanning Gate Microscopy

目的：本研究的目标是设计、制造和表征用于高分辨率扫描门显微镜的新型探针，这是一种提供电子分布和传输信息的技术。要将扫描门显微镜应用于半导体纳米结构，需要能够产生高度局域电势微扰的探针。提出的探头由带有集成同轴尖端的悬臂梁组成，以在下面的样品处产生受限的偶极电场。悬臂梁由尖端-表面相互作用引起的挠度将通过调节位于根部的压敏电阻来检测。最初，探测器将用于绘制量子点和其他半导体纳米结构中电子的概率密度，这是一个非常可取但尚未实现的目标。智力价值：智力价值包括对半导体纳米结构中电子组织的基本了解，解释这些低维系统的性质，以及设计新的器件(自旋电子、单电子等)。利用这些特性。除了扫描门显微镜，应用还包括对生物样本的研究、集成电路的失效分析以及半导体器件中噪声的研究。同轴针尖还可以提高扫描电化学显微镜和扫描近场显微镜的分辨率和对比度。更广泛的影响：由此产生的知识将具有广泛的社会、经济和教育影响。对细胞电压门控离子通道的更好理解可能会导致更有效的药物，而对量子点的更深入了解可能会产生更高性能的晶体管替代品。结果将通过教育推广计划传播。通过解决产生和检测局部电磁场的广泛问题，这些探测器将影响整个基础科学和工程领域的研究。

Objective:The goal of this research program is to design, fabricate and characterize novel probes for high-resolution scanning gate microscopy, a technique providing information on electron distribution and transport. Probes that can produce a highly-localized potential perturbation are needed to apply scanning gate microscopy to semiconductor nanostructures. The proposed probes consist of cantilevers with integrated coaxial tips to generate a confined dipolar electric field at the underlying sample. Deflection of the cantilever resulting from tip-surface interactions will be detected by modulation of a piezoresistor located at the root. Initially, the probe will be used to map the probability densities of electrons in quantum dots and other semiconductor nanostructures, which to-date is a highly-desirable but unrealized goal. Intellectual Merit:The intellectual merit includes fundamental understanding of electron organization in semiconductor nanostructures, explaining properties of these low-dimensional systems, and designing novel devices (spintronic, single-electron, etc.) exploiting these properties. Beyond scanning gate microscopy, applications include the investigation of biological specimens, failure analysis of integrated circuits, and the study of noise in semiconductor devices. The coaxial tip may also improve the resolution and contrast of scanning electrochemical microscopy and scanning near-field microscopy.Broader Impacts:The resulting knowledge will have broad social, economic, and educational impact. Improved understanding of cellular voltage-gated ion channels may lead to more effective drugs while greater insight into quantum dots may yield higher-performance replacements for transistors. Results will be disseminated through educational outreach programs. By addressing the broad problem of generating and detecting localized electromagnetic fields, the probes will influence research throughout the basic sciences and engineering.