Enhancement of MEMS-based Ga2O3 Gas Sensors by Surface Modifications

As a technology capable for low cost detection of volatile organic compounds, a completely new heated MEMS based gas sensor platform has been demonstrated, which allows for the first time a long term stable hotplate operation at temperatures up to 800 °C. In combination with the highly stable metal oxide Ga2O3 as sensing material, which requires these operation temperatures, combustible gas and VOC detection with improved stability and accuracy can be expected in comparison with commercial metal oxide sensors. The overall power consumption of the Ga2O3 based sensors has been reduced from 1 Watt for state-of-the-art ceramic sensor elements to a few mW for the MEMS based Ga2O3 sensors. The functionality of the MEMS Ga2O3 sensor device has been successfully demonstrated in synthetic gas mixtures as well as indoor environments. Significant improvement of selectivity has been achieved by additional surface modifications.