Open AccessImpact of the diaphragm structure on the linearity and temperature sensitivity of low-pressure piezo-resistive MEMS pressure sensors
Author(s) -
Nithin,
Rathnamala Rao,
K. N. Bhat
Publication year - 2020
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/872/1/012022
Subject(s) - wheatstone bridge , linearity , materials science , resistor , sensitivity (control systems) , microelectromechanical systems , pressure sensor , voltage , diaphragm (acoustics) , resistive touchscreen , repeatability , offset (computer science) , input offset voltage , compensation (psychology) , pressure measurement , electronic engineering , acoustics , electrical engineering , optoelectronics , engineering , computer science , mechanical engineering , cmos , operational amplifier , physics , psychoanalysis , psychology , amplifier , chemistry , chromatography , loudspeaker , programming language
This paper presents result of a detailed simulation study aimed at optimizing the different diaphragm structures of silicon micro machined MEMS pressure sensor for operation and measurement of the low-pressure ranges(600mbar). We first show that the conventional arrangement of the Wheatstone bridge resistors realized using the “Flat diaphragms” give rise to large temperature dependence of the offset voltage which affects the sensitivity and linearity of the pressure sensors during operation in the temperatures ranging from-40°Cto+80°C, thus making the temperature compensation of the sensor output voltage rather tedious and impossible in certain instances. We further demonstrate that, this issue can be circumvented and excellent linearity with minimum dependence of the offset-voltage, sensitivity and linearity can be achieved by using “sculptured diaphragms” with optimized diaphragm dimensions. Towards this goal, in this paper, we present a set of simulation studies involving optimization of the pressure sensor diaphragm dimensions and structures with single and multiple boss structures to achieve better sensitivity, linearity, and at the same time minimize temperature drift, and to achieve better repeatability.