Verifying finite element simulation in miniature silicon based stacked diaphragm pressure sensors

摘要

Micro electro mechanical system are usually defined as highly miniaturized devices combining both electrical and mechanical components that are fabricated using integrated circuit batch processing techniques. Silicon based stacked diaphragm structure is a combination of silicon-di-oxide and the silicon layer. This work brings out a new approach of finding the sensitivity of stacked diaphragm with respect one of the important parameters like deflection. The sensitivity is also evaluated under thermal effect and, the analytical model developed for the same closely matches with the finite element model. The doping concentration of 10~(17)cm~(-3), in which single silicon shows maximum sensitivity has been selected and an increase in the sensitivity is observed on using a stacked diaphragm structure. The stacked diaphragm structure is designed, simulated and compared with existing single diaphragm design with respect to diaphragm deflection and sensor output voltage for linearity over a wider range. The effect of the buried oxide in the stacked diaphragm structure is also considered in this work. The work in this paper provides a mathematical expression for realizing the effect of boron implanted resistors on the stacked diaphragm structure. The simulation result reported in the literature evaluates the deflection at a particular temperature but the new analytical model developed in this paper evaluates the sensitivity of the diaphragm over a temperature range.