Pt-AlGaN/GaN HEMT-sensor layout optimization for enhancement of hydrogen detection

摘要

This paper reports on the layout optimization of Pt-AlGaN/GaN HEMT-sensors for enhancing hydrogen sensor performance. Sensors with gate width and length ratios W_g/L_g from 0.25 to 10 were designed, fabricated and tested for the detection of hydrogen gas at 200°C. Sensitivity, sensing current variation and transient response are directly related to the sensor gate electrode W_g/L_g ratio. The obtained results demonstrated a 217% increase in sensitivity and 4630% increase in sensing current variation at 500 ppm H_2 for a W_g/L_g from 0.25 to 10. In addition, the detection limit was lowered to 5 ppm. Transient characteristics demonstrated faster sensor response to H_2, but slower recovery rates with increasing ratio.