Mechanical characteristics of deeply boron-doped silicon membranes for capacitive pressure sensors.

Abstract

SummaryThe mechanical behavior of deeply boron-doped silicon membranes is analyzed by using a simple analytical model. The boron-doped silicon membranes have intrinsic properties different from those of widely-used bulk silicon membranes: strong influence of a residual well as greatly decrease their sensitivity. This paper confirms the strong influence of these intrinsic properties on pressure-to-deflection response for boron-doped silicon flat and semi-bossed structures. By comparing the calculated values with measured values, an intuitive image for actual thin membranes is successfully obtained. Moreover, the temperature dependence of the capacitive sensors is discussed to propose a new model that considers the change in the residual stress and the elastic constant with temperature.The obtained results will be helpful in optimizing design parameters for capacitive pressure sensors.