Fabrication and Characteristics of an nc-Si/c-Si Heterojunction MOSFETs Pressure Sensor

Sensors

Xiaofeng Zhao²  Dianzhong Wen¹ 

[1] Key Laboratory of Electronics Engineering, College of Heilongjiang Province, Major Laboratories of Integrated Circuits, Heilongjiang University, Harbin 150080, China;

关键词: nc-Si/c-Si heterojunction;    MOSFETs pressure sensor;    MEMS technology;    CMOS process;   

DOI  :  10.3390/s120506369

来源: mdpi

【 摘 要 】

A novel nc-Si/c-Si heterojunction MOSFETs pressure sensor is proposed in this paper, with four p-MOSFETs with nc-Si/c-Si heterojunction as source and drain. The four p-MOSFETs are designed and fabricated on a square silicon membrane by CMOS process and MEMS technology where channel resistances of the four nc-Si/c-Si heterojunction MOSFETs form a Wheatstone bridge. When the additional pressure is P, the nc-Si/c-Si heterojunction MOSFETs pressure sensor can measure this additional pressure P. The experimental results show that when the supply voltage is 3 V, length-width (L:W) ratio is 2:1, and the silicon membrane thickness is 75 μm, the full scale output voltage of the pressure sensor is 15.50 mV at room temperature, and pressure sensitivity is 0.097 mV/kPa. When the supply voltage and L:W ratio are the same as the above, and the silicon membrane thickness is 45 μm, the full scale output voltage is 43.05 mV, and pressure sensitivity is 2.153 mV/kPa. Therefore, the sensor has higher sensitivity and good temperature characteristics compared to the traditional piezoresistive pressure sensor.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland