一种新型电容式压力传感器

提出了一种新的电容式压力传感器.传感器结构为由Al/SiO2/n-type Si等三层方形膜构成的固态电容.传感器采用pn结自停止腐蚀和粘结剂键合的方式制造,制造过程仅需三块掩模板.对不同边长传感器进行测试,在410～1010hPa的动态范围,边长为1000,1200和1400靘的压力传感器,相应灵敏度分别为1.8,2.3和3.6fF/hPa.边长为1500靘的传感器,其灵敏度为4.6fF/hPa,全程非线性度为6.4%,最大滞回误差为3.6%.分析结果表明介电常数变化是引起电容变化的主要原因.

A Novel Capacitive Pressure Sensor

A novel capacitive pressure sensor is presented,whose sensing structure is a solid-state capacitor consisting of three square membranes with Al/SiO2/n-type silicon. It was fabricated using pn junction self-stop etching combined with adhesive bonding, and only three masks were used during the process. Sensors with side lengths of 1000,1200, and 1400μm were fabricated,showing sensitivity of 1.8,2.3, and 3.6fF/hPa over the range of 410～1010hPa, respectively. The sensi- tivity of the sensor with a side length of 1500μm is 4. 6fF/hPa,the nonlinearity is 6.4% ,and the max hysteresis is 3.6%. The results show that permittivity change plays an important part in the capacitance change.