Title :
A Pd/Oxide/AlGaAs (MOS) junction resistor-type hydrogen sensor
Author :
Hung, Ching-Wen ; Chen, Huey-Ing ; Lin, Kun-Wei ; Tsai, Tsung-Han ; Chen, Tzu-Pin ; Chen, Li-Yang ; Chu, Kuei-Yi ; Liu, Wen-Chau
Author_Institution :
Dept. of Electr. Eng., Nat. Cheng-Kung Univ., Tainan
Abstract :
An interesting Pd/oxide/AlGaAs metal oxide semiconductor (MOS) junction resistor-type hydrogen sensor, based on the current-voltage characteristics in the linear region of an AlGaAs-based PHEMT structure, is fabricated and studied. A simple model is employed to elucidate the hydrogen detection mechanism. The dissociation of H2, diffusion of H atoms and formation of a dipole layer cause a in channel resistance, show that the VGS bias the resistance sensitivity, current variation, transient response, and response time. At 30degC, a significant resistance response of 33.3% (82.8%) to 4.3 (9970) ppm H2/air is obtained at VGS=-0.6 V. Nevertheless, the largest conductance variation (DeltaG) appears to be in the range between VGS=-0.3 and -0.4 V. The transient response at VGS=-0.3 V shows larger current variations, accompanying the longer response time than those at VGS=0 V.
Keywords :
III-V semiconductors; MIS devices; aluminium compounds; diffusion; dissociation; gallium arsenide; gas sensors; high electron mobility transistors; palladium; transient response; MOS junction resistor-type hydrogen sensor; PHEMT structure; Pd-AlGaAs; channel resistance; conductance; current-voltage characteristics; diffusion; dipole layer; dissociation; hydrogen detection mechanism; metal oxide semiconductor junction; pseudomorphic high electron mobility transistor; resistance sensitivity; response time; temperature 30 degC; transient response; voltage -0.3 V to -0.4 V; voltage -0.6 V; Delay; Equivalent circuits; Gallium arsenide; Gold; Hydrogen; PHEMTs; Schottky barriers; Stress; Temperature sensors; Transient response;
Conference_Titel :
Junction Technology, 2008. IWJT '08. Extended Abstracts - 2008 8th International workshop on
Conference_Location :
Shanghai
Print_ISBN :
978-1-4244-1737-7
Electronic_ISBN :
978-1-4244-1738-4
DOI :
10.1109/IWJT.2008.4540045