Array of Resonant Electromechanical Nanosystems: A Technological Breakthrough for Uncooled Infrared Imaging

Area of Science:

• Physics
• Electrical Engineering
• Materials Science

Background:

• Microbolometers are common uncooled infrared detectors but suffer from self-heating and 1/f noise.
• Achieving high temperature resolution (50 mK) with microbolometers is challenging due to inherent limitations.

Purpose of the Study:

• To present an alternative infrared detection approach using micro/nanoresonators.
• To demonstrate enhanced thermal response and reduced noise for infrared imaging.

Main Methods:

• Fabrication of dense arrays of electromechanical resonators with a 12 µm pitch using a post-processing method for CMOS integration.
• Design of H-shape pixels with 9 µm-long nanorods (250 nm x 30 nm) for optimal thermal response.
• Experimental measurement of thermal response, noise equivalent power, and response time.

Main Results:

• Experimental thermal responses reached up to 1024 Hz/nW.
• Electromechanical resonators achieved a noise equivalent power of 140 pW with a response time under 1 ms.
• Demonstrated potential for 20 mK temperature sensitivity at a 12 µm pitch with co-integration and a new readout scheme.

Conclusions:

• The developed micro/nanoresonator technology offers unrivaled performance for their small dimensions.
• This approach presents a promising alternative to microbolometers for uncooled infrared detection.
• Future enhancements, such as vanadium oxide deposition, could further improve thermal response by an order of magnitude.