TY - GEN
T1 - Hydrogen sensing characteristics of a Pd/GaAs semiconductor transistor-type sensor
AU - Hung, C. W.
AU - Chen, Huey-Ing
AU - Guo, D. F.
AU - Tsai, J. H.
AU - Cheng, S. Y.
AU - Tsai, Y. Y.
AU - Chen, T. P.
AU - Liu, Wen-Chau
PY - 2007/12/1
Y1 - 2007/12/1
N2 - An interesting Pd-GaAs high electron mobility transistor (HEMT) hydrogen sensor is fabricated and studied. For the studied device, a 5 nm-thick undoped GaAs cap layer is grown to suppress the oxidation of the underneath AlGaAs layer. Comprehensive analysis on the electrical properties including transconductance (gm), channel conductance (gD), and gate-source voltage shift (ΔVGS) is presented. Experimentally the maximum variation of transconductance (Δgm) is about 46.8 mS/mm while the maximum transconductance (gm,max) is still maintained at about 176 mS/mm. A high channel conductance variation (ΔgD) of 25.1 mS/mm is obtained in 9970 ppm H2/air gas at 50°C. This indicates that, in hydrogen-containing ambience, the channel resistance reduces in the linear region of transistor operation. The negative ΔVGS value in hydrogen-containing ambiance means that a lower VGS value is sufficient to maintain the same drain current (ID) value than that in air.
AB - An interesting Pd-GaAs high electron mobility transistor (HEMT) hydrogen sensor is fabricated and studied. For the studied device, a 5 nm-thick undoped GaAs cap layer is grown to suppress the oxidation of the underneath AlGaAs layer. Comprehensive analysis on the electrical properties including transconductance (gm), channel conductance (gD), and gate-source voltage shift (ΔVGS) is presented. Experimentally the maximum variation of transconductance (Δgm) is about 46.8 mS/mm while the maximum transconductance (gm,max) is still maintained at about 176 mS/mm. A high channel conductance variation (ΔgD) of 25.1 mS/mm is obtained in 9970 ppm H2/air gas at 50°C. This indicates that, in hydrogen-containing ambience, the channel resistance reduces in the linear region of transistor operation. The negative ΔVGS value in hydrogen-containing ambiance means that a lower VGS value is sufficient to maintain the same drain current (ID) value than that in air.
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U2 - 10.1109/SENSOR.2007.4300565
DO - 10.1109/SENSOR.2007.4300565
M3 - Conference contribution
AN - SCOPUS:50049085766
SN - 1424408423
SN - 9781424408429
T3 - TRANSDUCERS and EUROSENSORS '07 - 4th International Conference on Solid-State Sensors, Actuators and Microsystems
SP - 2043
EP - 2046
BT - TRANSDUCERS and EUROSENSORS '07 - 4th International Conference on Solid-State Sensors, Actuators and Microsystems
T2 - 4th International Conference on Solid-State Sensors, Actuators and Microsystems, TRANSDUCERS and EUROSENSORS '07
Y2 - 10 June 2007 through 14 June 2007
ER -