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Studying the Effect of Deposition Conditions on the Performance and Reliability of MEMS Gas Sensors

View Article: PubMed Central

ABSTRACT

In this paper, the reliability of a micro-electro-mechanical system (MEMS)-based gas sensor has been investigated using Three Dimensional (3D) coupled multiphysics Finite Element (FE) analysis. The coupled field analysis involved a two-way sequential electrothermal fields coupling and a one-way sequential thermal-structural fields coupling. An automated substructuring code was developed to reduce the computational cost involved in simulating this complicated coupled multiphysics FE analysis by up to 76 percent. The substructured multiphysics model was then used to conduct a parametric study of the MEMS-based gas sensor performance in response to the variations expected in the thermal and mechanical characteristics of thin films layers composing the sensing MEMS device generated at various stages of the microfabrication process. Whenever possible, the appropriate deposition variables were correlated in the current work to the design parameters, with good accuracy, for optimum operation conditions of the gas sensor. This is used to establish a set of design rules, using linear and nonlinear empirical relations, which can be utilized in real-time at the design and development decision-making stages of similar gas sensors to enable the microfabrication of these sensors with reliable operation.

No MeSH data available.


Effect of thermal conductivity variation of Si3N4 on the maximum thermal stress of different gas sensor materials
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f5-sensors-07-00319: Effect of thermal conductivity variation of Si3N4 on the maximum thermal stress of different gas sensor materials

Mentions: The structural analysis presented in this paper study the effect of the variation in the thermal, electrical and mechanical properties on the maximum generated stress in all the different thin film layers composing the studied MEMS-based gas sensor. In the electrothermal analysis, only the conductivity of Si3N4 and the resistivity of the heater material (Pt/Ti or polysilicon) were found to generate a significant effect on the thermal response of the modeled MEMS-based gas sensor [4]. Therefore, only the variations of these thermal/electrical parameters were considered in the current case. The variations of the maximum generated stress in various thin film layers versus the uncertainty in the thermal conductivity of Si3N4 and the electrical resistivity of Pt/Ti and polysilicon are shown in Figures 5, 6 and 7, respectively.


Studying the Effect of Deposition Conditions on the Performance and Reliability of MEMS Gas Sensors
Effect of thermal conductivity variation of Si3N4 on the maximum thermal stress of different gas sensor materials
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3756723&req=5

f5-sensors-07-00319: Effect of thermal conductivity variation of Si3N4 on the maximum thermal stress of different gas sensor materials
Mentions: The structural analysis presented in this paper study the effect of the variation in the thermal, electrical and mechanical properties on the maximum generated stress in all the different thin film layers composing the studied MEMS-based gas sensor. In the electrothermal analysis, only the conductivity of Si3N4 and the resistivity of the heater material (Pt/Ti or polysilicon) were found to generate a significant effect on the thermal response of the modeled MEMS-based gas sensor [4]. Therefore, only the variations of these thermal/electrical parameters were considered in the current case. The variations of the maximum generated stress in various thin film layers versus the uncertainty in the thermal conductivity of Si3N4 and the electrical resistivity of Pt/Ti and polysilicon are shown in Figures 5, 6 and 7, respectively.

View Article: PubMed Central

ABSTRACT

In this paper, the reliability of a micro-electro-mechanical system (MEMS)-based gas sensor has been investigated using Three Dimensional (3D) coupled multiphysics Finite Element (FE) analysis. The coupled field analysis involved a two-way sequential electrothermal fields coupling and a one-way sequential thermal-structural fields coupling. An automated substructuring code was developed to reduce the computational cost involved in simulating this complicated coupled multiphysics FE analysis by up to 76 percent. The substructured multiphysics model was then used to conduct a parametric study of the MEMS-based gas sensor performance in response to the variations expected in the thermal and mechanical characteristics of thin films layers composing the sensing MEMS device generated at various stages of the microfabrication process. Whenever possible, the appropriate deposition variables were correlated in the current work to the design parameters, with good accuracy, for optimum operation conditions of the gas sensor. This is used to establish a set of design rules, using linear and nonlinear empirical relations, which can be utilized in real-time at the design and development decision-making stages of similar gas sensors to enable the microfabrication of these sensors with reliable operation.

No MeSH data available.