工艺偏差对压阻式硅微压力传感器性能的影响

工艺实践表明,采用体硅湿法刻蚀工艺加工压阻式微型压力传感器时,敏感膜片会存在厚度偏差,电阻条偏离应力最大区域导致位置偏差,电阻条偏离期望的[110]晶向造成角向偏差.结合工艺实验并借助有限元法分析了上述几种主要工艺偏差对灵敏度、线性度等性能的影响.研究表明,2μm的厚度偏差会使灵敏度下降大约10%,线性度会明显下降;位置偏差会使敏感元件偏离应力最大区域而降低灵敏度:5°的电阻条角向偏差会使灵敏度下降大约3%.相关研究可为最大程度减小工艺偏差的影响提供参考依据.

Influence of Processing Deviation on Performance of Silicon-based Micro Piezoresistive Pressure Sensors

The experimental data indicate that there is the thickness deviation of sensitive membrane caused by silicon anise-tropic wet etching process, the position deviation of the resistor from the area with the largest stress, and the resistor's angular deviation from the expected orientation. With the experimental results, the influence of the processing deviations on sensitivity and linearity has been analyzed with the FEM (finite element method). The study showed that 2μm thickness deviation lead to 10% sensitivity loss and the linearity decrease, the position deviation of the resistors lead to the sensitivity decrease, and 5°angular deviation lead to about 3% loss of sensitivity.