WAFER-LEVEL PATTERNING OF TIN OXIDE NANOSHEETS FOR MEMS GAS SENSORS

Gas sensing materials are typically loaded on designated area of micro-electrode via drop-casting for application in gas sensors. However, wafer-level patterning of gas sensitive materials with good reproducibility still faces challenge. In this work, we develop an effective 'top-down' approach to produce wafer-scale miniaturized gas sensing devices with high-throughput using standard photolithography of a mixture of photoresist and tin oxide (SnO2) nanomaterials suspension, followed by calcination. The prepared gas sensing chips based on the proposed method exhibited satisfactory reproducibility and uniformity of sensing response toward ethanol detection, indicating promising application for large-scale production of MEMS gas sensors.