Fabrication and Characterization of a Micro Methanol Sensor Using the CMOS-MEMS Technique.

Area of Science:

• Materials Science
• Electrical Engineering
• Chemical Sensing

Background:

• Methanol gas detection is crucial for environmental monitoring and industrial safety.
• Existing sensors often lack sensitivity or require complex fabrication.
• Complementary Metal Oxide Semiconductor (CMOS)-Microelectromechanical System (MEMS) technology offers miniaturization and integration potential.

Purpose of the Study:

• To develop and characterize a novel methanol microsensor.
• To leverage CMOS-MEMS fabrication for enhanced sensor performance.
• To evaluate the sensor's sensitivity for low-concentration methanol gas detection.

Main Methods:

• Fabrication of a microsensor using CMOS-MEMS techniques.
• Integration of a microheater for optimal working temperature.
• Deposition of a sensitive film (tin dioxide doped cadmium sulfide) via sol-gel method.
• Post-CMOS processing for suspended structure formation.
• Resistive sensing mechanism with a readout circuit.

Main Results:

• Successful fabrication of a methanol microsensor with a suspended structure.
• The sensor demonstrated capability for detecting low concentrations of methanol gas.
• Achieved a notable sensitivity of 0.18 V/ppm for methanol detection.

Conclusions:

• The developed CMOS-MEMS methanol microsensor is effective for low-concentration gas detection.
• The integrated microheater and sensitive film composition contribute to sensor performance.
• This technology shows promise for portable and sensitive methanol gas sensing solutions.