掺杂n^(+) GaAs的热电式MEMS微波功率传感器在Ka波段的研究  

Study on Thermoelectric MEMS Microwave Power Sensor with Doped n^(+)GaAs at Ka-Band

作　　者：洪阳 张志强[1] 孙国琛 郑从兵 刘佳琦 HONG Yang;ZHANG Zhiqiang;SUN Guochen;ZHENG Congbing;LIU Jiaqi(Key Laboratory of MEMS of the Ministry of Education,Southeast University,Nanjing Jiangsu 210096,China)

机构地区：[1]东南大学MEMS教育部重点实验室,江苏南京210096

出　　处：《传感技术学报》2022年第2期143-147,共5页Chinese Journal of Sensors and Actuators

基　　金：国家自然科学基金项目(61604039);至善青年学者支持计划项目(2242019R40030)。

摘　　要：本文主要通过理论设计和性能测试,研究了热电堆的半导体臂n^(+)GaAs的掺杂浓度对热电式MEMS微波功率传感器在Ka波段工作性能的影响。该类传感器基于微波功率-热-电转换原理工作,其中热电堆是由半导体臂n^(+)GaAs和金属臂Au构成。通过建立理论分析模型,探究了灵敏度、信噪比与掺杂浓度之间的关系,以指导传感器的结构设计,并基于GaAs MMIC工艺制备了四种n^(+)GaAs掺杂浓度下MEMS微波功率传感器。实验结果表明:当n^(+)GaAs掺杂浓度分别为2.4×10^(18) cm^(-3)、8.5×10^(17) cm^(-3)、3.2×10^(17) cm^(-3)和1.9×10^(17) cm^(-3)时,测量的灵敏度在30 GHz分别为15.21μV/mW、17.86μV/mW、74.36μV/mW和142.34μV/mW,而其在38 GHz分别为10.91μV/mW、17.88μV/mW、48.94μV/mW和98.59μV/mW,该结果表明灵敏度随掺杂浓度增大而减小;信噪比在30 GHz分别为8.58×10^(5) W^(-1)、6.13×10^(5) W^(-1)、1.38×10^(6) W^(-1)和2.08×10^(6) W^(-1),而其在38 GHz分别为6.44×10^(5) W^(-1)、6.13×10^(5) W^(-1)、1.11×10^(6) W^(-1)和1.47×10^(6) W^(-1),该结果表明信噪比随掺杂浓度的增大先减小再增大。In this paper,the influence of the n^(+)GaAs doping concentration in semiconductor arms of the thermopile on the performance of thermoelectric MEMS microwave power sensor at Ka-band is researched through the theoretical design and performance test.This type of sensor is based on the operation principle of microwave power-heat-electricity conversion,where the thermopile is composed of the semiconductor arms n^(+)GaAs and the metal arms Au.Through the establishment of a theoretical analysis model,the relationships between the sensitivity,signal-to-noise ratio and doping concentration are explored to guide the structural design of the sensor.Four MEMS microwave power sensors with the different n^(+)GaAs doping concentration are fabricated based on the GaAs MMIC process.The experimental results show that when the n^(+)GaAs doping concentration is 2.4×10^(18) cm^(-3),8.5×10^(17) cm^(-3),3.2×10^(17) cm^(-3) and 1.9×10^(17) cm^(-3),the sensitivity is 15.21μV/mW,17.86μV/mW,74.36μV/mW and 142.34μV/mW at 30 GHz,and 10.91μV/mW,17.88μV/mW,48.94μV/mW and 98.59μV/mW at 38 GHz,respectively,which shows that the sensitivity decreases with the increase of the doping concentration,while the signal-to-noise ratio is 8.58×10^(5) W^(-1),6.13×10^(5) W^(-1),1.38×10^(6) W^(-1) and 2.08×10^(6) W^(-1) at 30 GHz,and 6.44×10^(5) W^(-1),6.13×10^(5) W^(-1),1.11×10^(6) W^(-1) and 1.47×10^(6) W^(-1) at 38 GHz,which shows that the signal-to-noise ratio first decreases and then increases with the increase of the doping concentration.

关 键 词：MEMS 微波功率传感器 掺杂n^(+)GaAs 灵敏度 信噪比 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]