介观压阻效应及器件

介绍GaAs/AlAs/InGaAs双势垒超晶格薄膜结构的介观压阻效应以及几种基于此效应的新型传感器件。阐述介观压阻效应的四个过程，结合空气桥结构和欧姆接触技术，在001]晶向半绝缘GaAs衬底上加工出来了GaAs/AlAs/InGaAs共振隧穿结构(Resonant tunneling structures, RTS)，并对其进行了加压试验研究，发现其介观压阻灵敏度达到2.54×10–9 Pa–1，是硅压阻灵敏度的一个数量级以上。采用控制孔技术成功加工出了基于RTS的圆膜压力、四梁加速度和仿生矢量水声三种新型纳机电器件，并分别对其进行了压力罐、振动台和水下驻波测试。结果表明圆膜压力传感器具有较好的力电耦合特性；四梁加速度计的压阻灵敏度随RTS两端偏置电压可调，并在微分负阻区具有最大压阻灵敏度；矢量水听器具有良好的“8”字余弦指向性，灵敏度在1 000 Hz时达到184.6 dB，可以实现水平面内的水下声信号探测。

Meso-piezo-resistive Effect and Devices

The meso-piezoresistive effect of GaAs/AlAs/InGaAs double barrier supper-lattice thin films and some new types of sensor based on this effect are introduced. The four steps of meso-piezoresistive effect are demonstrated, and the GaAs/AlAs/InGaAs resonant tunneling structure (RTS) is processed on 001] crystal orientation semi-insulating substrate. Pressure measurements show that its meso-piezoresistive sensitivity reaches 2.54×10–9 Pa–1, which is an order higher than that of silicon. The Nano-electromechanical sensors, such as membrane pressure sensor, four-beam accelerometer and bionic vector hydrophone, are fabricated successfully by micro control-hole technology, and they are measured in pressure tank, vibration table and standing wave tube respectively. Measurement results show that the membrane pressure sensor has good electro-mechanical coupling characteristics; the piezoresistive sensitivity of four-beam accelerometer can be adjusted by the biased voltage of RTS, and the largest sensitivity is in the negative differential resistance (NDR) region; The vector hydrophone has excellent “8” cosine directivity, and its sensitivity reaches –184.6 dB at 1 000 Hz, which can realize horizontal underwater sound signal detection.