III-N Hot Electron Transistors for high-frequency amplification
Abstract
Short Statement of work Funds are provided to investigate approaches to achieve TeraHertz operation in Hot Electron Transistors. The PI is Prof. Umesh Mishra, the performer is the University of Santa Barbara. This grant has a three year period of performance with total funding of $600,000 This action provides an initial increment of $100K In prior work, N-Polar Hot Electron Transistors (HET)s performed much better than Ga-Polar HETs on base resistance, turn-on voltage, breakdown voltage, and current density. However, high current gain is very difficult to achieve in N-Polar HETs due to unfavorable band shape for the emitter injector barrier. The Ga-Polar HET has much higher current gain, but has lower breakdown voltages, current density and higher base resistance. Since current gain is one of the most important metrics for transistor performance, this effort will investigate device physics for simultaneous improvements in breakdown voltage, base resistance, and current density of Ga-Polar HETs with the goal of device performance approaching THz performance for an amplifier. Approach: This effort will investigate device growth on bulk substrates to reduce the dislocation density in the active area of the device in order to reduce the leakage currents and increase the breakdown voltage. The reduced leakage currents will enable a further investigation of the role of the injection barrier height on the gain and current density of the hot electrons passing through the base. The device structure geometry will be realized with a self-aligned process in order to maximize the frequency performance through the reduction in parasitic capacitances, contact and base resistance. Objective: The objective of this effort is to investigate device physics for simultaneous improvements in breakdown voltage, base resistance, current density and current gain of Ga-Polar HETs with the goal of device performance approaching THz performance for an amplifier. Merit/relevance The HET is a leading device approach for high frequency vertical transistors in the GaN materials system. This effort will expand the understanding of basic electron transport physics in ultra-small geometries and will enable a new THz amplifier technology for future Navy surveillance and communication systems.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jun 10, 2016
- Source ID
- N000141612250
Entities
People
- Umesh Mishra
Organizations
- Office of Naval Research
- United States Navy
- University of California, Santa Barbara