Nonlinear analyses on CMOS integrated silicon pressure sensor

This paper reports theoretical and experimental results of analysis on nonlinear characteristics, for the newly designed CMOS integrated pressure sensor with square silicon diaphragm. It is shown that nonlinearity is caused by both the large diaphragm deflection effect and nonlinear piezoresistance effect of resistors. The optimum layout for piezoresistors to minimize their nonlinearity is also shown. The measured nonlinearity for the fabricated device quantitatively agrees well with the numerically analyzed nonlinearity.