AlGaN/GaN pressure sensor with a Wheatstone bridge structure
AlGaN/GaN pressure sensor with a Wheatstone bridge structure
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惠斯通电桥结构的 AlGaN/GaN 压力传感器
DOI：
10.1063/1.4996257
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发表时间：
2018-08-01
期刊：
影响因子：
1.6
通讯作者：
Cai, S. J.
中科院分区：
文献类型：
--
作者：
Tan, X.;Lv, Y. J.;Cai, S. J.
本文首次研制了基于AlGaN/GaN异质结的惠斯通电桥型压力传感器。该压力传感器由4个无栅高电子迁移率晶体管(HEMT)组成，在厚度为585μm的圆形薄膜上留有15μm厚的硅衬底。实现了AlGaN/GaN压力传感器的直接电压读出，在0.1Mpa~5 Mpa的较宽压力范围内，其非线性系数为0.6%，灵敏度为1.25μV/kpa/V。由于面内各向同性的特性，AlGaN/GaN压力传感器的工作机理与硅基传感器有很大的不同。虽然四种无栅HEMT的电阻都随着压力的增大而增加，但在压电效应下相邻电阻的变化随着排列的不同而变化。最后利用惠斯通电桥电路的差动运算实现了电压的线性读出。
In this work, a Wheatstone bridge-type pressure sensor based on AlGaN/GaN heterostructure was fabricated for the first time. The pressure sensor consisted of four gateless high electron mobility transistors (HEMTs) on a 585 μm depth circular membrane, in which 15-μm-thick silicon substrate was left. Direct voltage readout was realized in the AlGaN/GaN pressure sensor, which exhibited a non-linearity of 0.6% with a sensitivity of 1.25 μV/kPa/V over a wide pressure range from 0.1 MPa to 5 MPa. Because of the in-plane isotropic properties, the working mechanism in the AlGaN/GaN pressure sensor is found to be quite different from the silicon-based sensor. Although the resistances of the four gateless HEMTs all increased with enlarging pressure, the changes of neighboring resistors varied with alignments under the piezoelectric effects. Finally, voltage linear readout was realized by the differential operation of Wheatstone bridge circuit.