Wafer-Level Patterning of SnO2 Nanosheets for MEMS Gas Sensors

In the past few decades, gas sensitive nano-materials are usually deposited on specific area of the wafer by drop-casting or inkjet printing for application in gas sensor fabrication. However, wafer-level patterning of sensing materials with satisfactory reproducibility still encounters challenge. In this letter, we propose a facile lop-down' strategy to manufacture wafer-scale gas sensing chips with high-throughput by photolithography using a well-mixed photoresist-nanomaterial suspension, followed by calcination. The fabricated gas sensors based on the proposed approach yield excellent reproducibility and uniformity of sensing response to ethanol detection with a relative standard deviation (RSD) <4.5 %, suggesting promising application for high-volume production of MEMS compatible gas sensors.

Automated summary

Gas sensitive nano-materials have traditionally been deposited on specific areas of a wafer using drop-casting or inkjet printing for gas sensor fabrication. However, achieving reproducibility in wafer-level patterning of sensing materials has been a challenge. In this study, a simple top-down approach using photolithography and a well-mixed photoresist-nanomaterial suspension followed by calcination was proposed for the fabrication of wafer-scale gas sensing chips. The gas sensors produced using this method showed excellent reproducibility and uniformity in sensing response to ethanol detection, making it promising for high-volume production of MEMS compatible gas sensors.