THE APLLICATION OF V-GROOVE SLOT-ARRAY METHOD TO THE PIEZORESISTIVE PRESSURE SENSORS

摘要

This paper describes a simple method to identify the membrane thickness of the piezoresistive pressure sensor by the so-called "slot-array" which has been made in advance on the wafers before sensor fabrication. Such a method can be applied as a substitute for other etch-stop techniques with micrometer-resolution. The results can also be used to check the uniformity of pressure sensors and give a guide-line for further improvements in the batch process of silicon bulk micromachining. A series of pressure sensors with a chip size of 3x3x0.2mm3 were presented as the examples of the V-groove slot-array method. The fi-nite element method (FEM) software ANSYS was accessed to predict the stress and resistance change of the sensors. The new pressure sen-sors with stiffened-bosses are tested and had a best sensitivity of 9.0 mV/atm/V and a non-linearity less than 1%.