Non-Linear Device Applications of Nano-Patterned Barium Strontium Titanate Thin Films

目的-本研究的目的是研究钛酸钡锶（BST）薄膜的纳米级活性区域的非线性特性，它们对沉积和图图化过程的依赖，以及它们在宏观尺度上的表现，包括电容-电压行为。该项目的重要目标包括基于非线性传输线拓扑的BST电路的非线性计算机辅助设计模型和设计技术的发展。该方法是使用平面电容器（变容管）结构，在BST薄膜上分层，作为更复杂器件的构建块。这些结构将使用聚焦离子束（FIB）铣削来制造纳米级的间隙。智力优势-将开发的变容管具有与薄膜表面粗糙度相同数量级的特征尺寸-在这个尺度上，薄膜的均匀性和由此产生的电容电压特性，开关速度和介电弛豫还没有得到很好的理解。利用微波信号生成的BST将需要对非线性特性和建模方法的进步有透彻的了解。更广泛的影响-将开发的设备可以对整个社会产生巨大影响，因为其功能是军事雷达和许多商业电信系统等专业系统的组成部分。此外，所获得的关于BST非线性行为的基本知识将对高密度存储器等相关领域的工程师和物理学家有用。pi在研究活动中有涉及代表性不足的少数民族的记录，并将招募女性和少数民族学生来完成这项工作。

Objective - The objective of this research is to investigate the non-linear properties of nano-scale active regions of barium strontium titanate (BST) thin films, their dependence upon deposition and patterning processes, and their manifestation in macro-scale observables including capacitance-voltage behavior. Important goals for this project include the development of non-linear computer-aided-design models and design techniques for BST circuits based on non-linear transmission line topologies. The approach is to use planar capacitor (varactor) structures, layered on a BST film, as the building block for more complex devices. The structures will be patterned using focused ion beam (FIB) milling to create nano-scale gaps. Intellectual Merit - The varactors that will be developed have feature sizes on the same order of magnitude as the film's surface roughness - at this scale, the homogeneity of the film and resultant capacitance-voltage properties, switching speed and dielectric relaxation are not well understood. The exploitation of BST for microwave signal generation will require a thorough understanding of the non-linear properties and advancements in modeling methodologies.Broader Impact - The devices that will be developed can have a great impact on society at large, as the functionality is integral to specialized systems such as military radar and many commercial telecommunications systems. Furthermore, the fundamental knowledge gained on non-linear behavior of BST will be useful to engineers and physicists working in related fields such as high-density memory. The PIs have a track-record of involving under-represented minorities in their research activities and will recruit female and minority students to perform this work.