Collaborative Research EAGER: Reliable High Current Density Vacuum Electronics

合作研究 EAGER：可靠的高电流密度真空电子器件

• 批准号: 1450508
• 负责人: Siddharth Rajan
• 金额: $ 13万
• 依托单位: Ohio State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1450508&HistoricalAwards=false
• 关键词: Collaborative; Research; EAGER; Reliable; Current

Vacuum electronic devices and systems, which are based on the control of electron motion through vacuum, have numerous applications including plasma displays, microwave and terahertz radiation sources for communications and imaging, scanning electron microscopes, and electronics for extreme environments. However, devices that efficiently and reliably emit electrons into vacuum have been challenging due to their low current density and poor reliability. The proposed project, a collaboration between Purdue University and Ohio State University, aims to demonstrate new designs for vacuum emitters to enable them to operate reliably at high current densities. Two complementary approaches involving two different semiconductors - Silicon and Gallium Nitride will be used to demonstrate vacuum emitters, guided by detailed electronic and thermal modeling techniques. The proposed work will enable realization of high-performance vacuum electronic devices that can be integrated on semiconductor chips at the micrometer scale. These microscale high current density emitters would surpass the current state-of-art and could enable a large array of new applications that exploit vacuum electronics for display, high data-rate communications, high-temperature electronics, and imaging. The project will lead to training and education of graduate students in a highly interdisciplinary and novel area of semiconductor technology, and could lead to several new commercially relevant applications for vacuum electronic circuits and systems.This collaborative project will combine the complementary expertise in Si fabrication and vacuum electronics at Purdue University, and III-nitride heterostructure and polarization engineering at Ohio State University to demonstrate reliable high current density emitters. A new approach to Si field emitters will be investigated to take advantage of current saturation effects in Silicon with fairly low carrier concentration, The Si emitters will be designed to control current density through lattice and ionized impurity scattering limited transport. A parallel approach using heterostructure and polarization engineering will be pursued to achieve highly efficient field emission in planar III-nitride semiconductor structures. III-nitride semiconductors have intrinsic polarization that enables large voltages to be dropped across nanometer scale distances. This enables field engineering to align the conduction band within the semiconductor with the vacuum level outside. The polarization engineering concepts will be combined with ballistic transport in ultrascaled structures to achieve efficient field emission from III-nitride semiconductor surfaces. The proposed device will enable high current density field emission in planar geometries that could be advantageous for several applications. Sophisticated modeling techniques including 2-dimensional electro-thermal simulations and Monte Carlo simulations of transport in heterostructures will be developed at Purdue University and Ohio State University to design and evaluate the vacuum emitters in both Silicon and III-nitride material systems. Development and demonstration of micro-fabrication technology for integrated vacuum electronic devices will be done. The proposed work would lead to better understanding of field emission from engineered nanoscale structures and III-nitride semiconductors. The concepts proposed here use promising and novel approaches for overcoming challenges related to high current density emitters, and could therefore have transformative impact on the science and applications of vacuum microelectronics.

真空电子设备和系统基于对真空中电子运动的控制，具有多种应用，包括等离子体显示器、用于通信和成像的微波和太赫兹辐射源、扫描电子显微镜以及用于极端环境的电子设备。然而，由于电流密度低且可靠性差，高效可靠地将电子发射到真空中的器件一直具有挑战性。拟议的项目是普渡大学和俄亥俄州立大学之间的合作项目，旨在展示真空发射器的新设计，使其能够在高电流密度下可靠运行。涉及两种不同半导体（硅和氮化镓）的两种互补方法将用于演示真空发射器，并以详细的电子和热建模技术为指导。拟议的工作将能够实现可集成在微米级半导体芯片上的高性能真空电子器件。这些微型高电流密度发射器将超越当前的技术水平，并可实现大量利用真空电子器件进行显示、高数据速率通信、高温电子器件和成像的新应用。该项目将在半导体技术的高度跨学科和新颖领域对研究生进行培训和教育，并可能导致真空电子电路和系统的几个新的商业相关应用。该合作项目将结合普渡大学硅制造和真空电子学以及俄亥俄州立大学的III族氮化物异质结构和极化工程方面的互补专业知识，以展示可靠的高电流 密度发射器。将研究一种新的硅场发射体方法，以利用载流子浓度相当低的硅中的电流饱和效应，硅发射体将被设计为通过晶格和电离杂质散射限制传输来控制电流密度。将采用异质结构和极化工程的并行方法，以在平面 III 族氮化物半导体结构中实现高效场发射。 III 族氮化物半导体具有本征极化，可以在纳米级距离上降低大电压。这使得现场工程能够将半导体内的导带与外部的真空水平对齐。偏振工程概念将与超尺度结构中的弹道输运相结合，以实现 III 族氮化物半导体表面的高效场发射。所提出的装置将能够在平面几何形状中实现高电流密度场发射，这对于多种应用来说是有利的。普渡大学和俄亥俄州立大学将开发复杂的建模技术，包括异质结构中的二维电热模拟和蒙特卡罗输运模拟，以设计和评估硅和III族氮化物材料系统中的真空发射器。开展集成真空电子器件微加工技术开发与示范。拟议的工作将有助于更好地理解工程纳米级结构和 III 族氮化物半导体的场发射。这里提出的概念使用有前景的新颖方法来克服与高电流密度发射器相关的挑战，因此可能对真空微电子学的科学和应用产生变革性的影响。