A new SiC/HfB2 based low power gas sensor

A new SiC-based heated micro gas sensor with a 100μm×100μm heated membrane and excellent heater long-term stability is presented. Combining a previously presented micro hotplate with new gas sensitive (211) oriented In2O3 thin film layers yields a very stable low power NO2 gas sensor. The modular design allows its operation at operating voltages of either 1–2 or 12–24V for battery and grid powered automotive applications. A total of 20mW of power is sufficient for the operation at 250°C. The sensitivity and signal reproducibility in the MAK-range (5ppm, maximum workplace concentration according to German federal law) is good. The response time τ50=50s needs improvement.