A Novel $\hbox{Pt/In}_{0.52}\hbox{Al}_{0.48}\hbox{As}$ Schottky Diode-Type Hydrogen Sensor
On the basis of a Pt/In0.52Al0.48As metal-semiconductor structure, a novel hydrogen sensor is fabricated and demonstrated. The studied Pt/In0.52Al0.48As Schottky diode-type hydrogen sensor exhibits significant sensing performance including high relative sensitivity ratio of about 2600% (under the 1% H2/air gas and VR=-0.5 V at 30 degC), large current variation of 310 muA (under the 1% H2/air gas and VR=-5 V at 200 degC), widespread reverse-voltage regime (0~-5 V), stable hydrogen-sensing current-voltage (I-V) curves, and fast transient response time of 1.5 s. The calculated Schottky barrier-height change and series-resistance variation, from the thermionic-emission model and Norde method, are 87.0 meV and 288 Omega, respectively (under the 1% H2/air gas at 30 degC). The hydrogen concentrations and operating temperatures tested in this letter are in the range of 15 ppm-1% H2/air and 30 degC-250 degC, respectively. Based on the excellent integration compatibility with InP-based electronic devices, the studied device provides the potentiality in high-performance sensor-array applications
A study on metal-insulator-silicon hydrogen sensor with La2O3 as gate insulator
A new MIS Schottky-diode hydrogen sensor with La<inf>2</inf>O<inf>3</inf> as gate insulator was fabricated. Its hydrogen-sensing properties were studied from room temperature (RT) to 300°C. Results showed that the device had excellent hydrogen-sensing performance below about 250°C.
Chemical sensors with catalytic metal gates
We first review the principles of gas sensitive field effect devices with catalytic metal gates. A discussion about recent experiments under ultrahigh vacuum conditions is given. More particularly, we consider the properties of the interface between the catalytic metal and the insulator it is evaporated on. A few more of the applied research areas related to these devices are also discussed and some remaining research problems are suggested.