Polymer Ring-Flexure-Membrane Suspended Gate FET Gas Sensor: Design, Modelling and Simulation.

Area of Science:

• Materials Science
• Electrical Engineering
• Mechanical Engineering

Background:

• Microelectromechanical systems (MEMS) offer miniaturized solutions for gas sensing.
• Existing gas sensors face challenges in sensitivity and consistent performance.
• Polymer-based MEMS devices are emerging for specialized sensing applications.

Purpose of the Study:

• To design, model, and simulate a novel polymer MEMS gas sensor platform.
• To enhance gas adsorption transduction efficiency and improve sensor sensitivity.
• To evaluate the sensor's performance for hydrogen gas detection.

Main Methods:

• Utilized a ring-flexure-membrane (RFM) structure integrated with a suspended gate field effect transistor (SGFET).
• Employed finite element method (FEM) and TCAD simulation tools (CoventorWare, Synopsis Sentaurus TCAD).
• Designed and simulated a differential amplifier circuit using Cadence Virtuoso.

Main Results:

• The RFM-SGFET architecture ensures constant gate capacitance change during gas adsorption.
• Achieved a differential amplifier sensitivity of 2.8 mV/MPa at 3 V gate bias.
• Demonstrated a maximum hydrogen gas detection range of up to 1% concentration.

Conclusions:

• The novel RFM-SGFET platform significantly improves gas sensing sensitivity and transduction efficiency.
• The proposed design and simulation pave the way for advanced polymer MEMS gas sensors.
• A fabrication process integration plan using CMOS and surface micromachining is presented.