An Ultra-Compact MEMS Pirani Sensor for In-Situ Pressure Distribution Monitoring

Area of Science:

• Materials Science and Engineering
• Electrical Engineering
• Physics

Background:

• Pirani vacuum sensors are crucial for pressure measurement.
• Existing MEMS Pirani sensors often lack sufficient compactness or high responsivity.
• There is a need for miniaturized vacuum sensors for diverse applications.

Purpose of the Study:

• To design and fabricate an ultra-compact microelectromechanical system (MEMS) Pirani vacuum sensor.
• To evaluate the performance and responsivity of the fabricated sensor in low-pressure domains.
• To explore potential applications for the developed MEMS Pirani vacuum sensor.

Main Methods:

• Sensor design based on the Pirani principle.
• Fabrication using a commercial eight-inch MEMS foundry process with four photomasks.
• Vacuum measurement system setup for comprehensive sensor evaluation.
• Performance testing focusing on responsivity in low-pressure ranges (100 Pa down to 1 Pa).

Main Results:

• Successful fabrication of an ultra-compact MEMS Pirani vacuum sensor (<2.2 × 2.2 mm2).
• High responsivity demonstrated in the low-pressure domain starting from 100 Pa.
• Achieved average responsivity of 11.9 mV/Pa (100-7 Pa) and 96.0 mV/Pa (7-1 Pa) with a 953.0-Ω heater.
• Sensor performance validated through a dedicated vacuum measurement system.

Conclusions:

• The developed MEMS Pirani vacuum sensor offers a highly compact solution for vacuum measurement.
• The sensor exhibits excellent responsivity, particularly in the critical low-pressure ranges.
• Potential applications include vacuum indicators, health monitoring, and medical devices.