基于高迁移率晶体管的氮化镓微机械谐振器  

Gallium nitride micro electro mechanical resonator based on high electron mobility transition

作　　者：郭兴龙[1] 朱友华[1] 葛梅 李毅[1] 邓洪海[1] GUO Xinglong;ZHU Youhua;GE Mei;LI Yi;DENG Honghai(School of Information Science and Technology,Nantong University,Nantong 226019,China)

机构地区：[1]南通大学信息科学技术学院,江苏南通226019

出　　处：《南通大学学报（自然科学版）》2022年第2期65-72,共8页Journal of Nantong University(Natural Science Edition)　

基　　金：国家自然科学基金面上项目(62074086,61874168);国家自然科学基金青年科学基金项目(62004109);江苏省产学研项目(21ZH626)。

摘　　要：文章设计了一款基于氮化镓(GaN)的微机械谐振器。该器件采用氮化镓具有较高的声速和优异的压电系数性质及其二维电子气(two-dimensional electron gas,2DEG)作为可开关嵌入电极,通过压电材料薄膜内正交应力(σ_(x)和σ_(y))产生厚度剪切振动模式实现增强器件振荡特性;采用平面和微机械工艺进行流片,详细说明了器件工艺过程,特别是肖特基和欧姆接触工艺,得到了尺寸为70μm×100μm谐振单元物理。该器件由电极、压电薄膜、电极组成高迁移率晶体管(high electron mobility transition,HEMT)结构,使得谐振器增加了机电共振效果。测试结果表明器件的谐振频率为26.3 MHz,品质因数为2620。通过实验对器件施加不同的栅极电压,在AlGaN/GaN界面上由于自发极化和压电极化而能够产生较大电荷密度和较高速的电子迁移率的二维电子气层。实验结果表明:HEMT的栅极电压引起的沟道的2DEG对谐振器的机电转换特性具有一定的影响,提高了谐振器的性能。该研究对于谐振器的研制具有一定的指导意义。A micromechanical resonator based on gallium nitride(GaN)is presented.The resonator is made by applying the high sound velocity and excellent piezoelectric coefficient of gallium nitride.The two-dimensional electron gas(2DEG)is used as a switchable embedded electrode,through the normal stress in the piezoelectric material film(σ_(x) and σ_(y)),the thickness shear vibration mode is produced to fortify the oscillation characteristics.The high electron mobility transition(HEMT)structure of the device is composed of electrode,piezoelectric film and electrode,and can increase the electromechanical resonance effect of the resonator.The test results show that the resonant frequency of the device is 26.3 MHz with the quality factor of 2620.By applying different gate voltages to the device,the 2DEG layer with large charge density and high electron mobility form at the AlGaN/GaN interface due to spontaneous polarization and piezoelectric polarization.In addition,the experimental results also illustrate that the channel 2DEG caused by the gate voltage of HEMT has a certain impact on the electromechanical conversion characteristics of the resonator and thus improves the resonator′s performance.This study has instructive significance in micromechanical resonator development.

关 键 词：氮化镓 高迁移率晶体管 微机械谐振器 二维电子气 

分 类 号：TN385[电子电信—物理电子学]