Methane Gas (CH4) detection using an (EGFET) Extended Gate CMOS microsensor

To reduce the number of fatal accidents in hostile and dangerous environments for humans, today, it is necessary to harmful gases measure using portable systems that employ sensors based on microelectronics. Therefore, in this work, the main structure of an extended gate CMOS microsensor is presented where a vanadium oxide (VO
2
) layer has been incorporated as a methane gas (CH
4
) detection membrane to analyze the behavior of the proposed device. The complete microsensor is composed of an NMOS transistor and an extended gate (EGFET), using 0.5 μm ON Semiconductor CMOS processess, with V
DS
bias voltages less than 1 V and V
GS
voltage less than 1 V, for it to work in the linear region. Preliminary results performed in TopSPICE software showing an optimal behavior. I
DS
vs V
DS
characteristics curve simulations of the layout and 2D numerical simulations with the VO
2
sensitive membrane film using the silvaco TCAD software are presented.