Investigation of strain-engineering techniques for modification of the characteristics of FETs in polar III-nitride material system and analytical modeling of device peculiarities

在过去的十年中，极性AlGaN/GaN异质结构场效应晶体管（HFET）一直是器件研究界的焦点，作为高功率，高电压微波应用的诱人候选人。宽禁带AlxGa 1-xN材料系统的高温度稳定性和大击穿电压促进了AlGaN/GaN HFET作为高压/高温条件下开关应用的重要候选者的适用性。鉴于对传感设备的可靠性改进的日益增长的需求以及电动车辆的普及的激增，需要能够在超出硅技术所提供的温度和电压范围的温度和电压范围下操作的功率谨慎的固态电子电路。据PI所知，尚未从提供常关（零栅极电压下的零电流）HEFT的工艺开发要求和常关/常开（零栅极电压下的非零电流）对的可重复制造挑战的角度，对宽带隙极性III族氮化物材料系统在开关模式电子器件中的应用进行系统研究。这项发现补助金提案的结果将导致改进的方法，用于分析，设计和评估极性材料系统中的固态电子器件和电路，以有效利用这种相对较新的电子材料家族的材料特性。此外，分析模型将开发纳入AlGaN/GaN HFET的漏电流崩溃和过度的栅极泄漏。

During the past decade, polar AlGaN/GaN heterostructure field effect transistors (HFETs) have been the focus of the device research community as alluring candidates for high power, high voltage microwave applications. High temperature stability and large breakdown voltage of wide-bandgap AlxGa1-xN material system, promote the applicability of AlGaN/GaN HFETs as vital candidates for switching applications under high-voltage/high-temperature conditions. In light of the growing demand for reliability improvement of the sensory equipment and surge in popularity of electric vehicles, power-prudent solid state electronic circuits capable of operating at temperature and voltage ranges beyond those offered by silicon technology are in demand. To the best of the PI's knowledge, a systematic investigation of the application of wide-bandgap polar III-Nitride material system to switching-mode electronics from the standpoints of process-development requirements for offering normally-off (zero current at zero gate voltage) HEFTs and challenges of reproducible fabrication of normally-off/normally-on (nonzero current at zero gate voltage) pair has not been performed. Results of this Discovery Grant proposal will lead to improved methods for analysis, design, and evaluation of solid state electronic devices and circuits in polar material systems for the efficient exploitation of the material properties of this relatively new family of electronic materials. Moreover, analytical models will be developed for incorporation of drain-current collapse and excessive gate leakage of AlGaN/GaN HFETs.