The interesting hydrogen sensing performances of a Pt-oxide-AlGaAs (MOS) high electron mobility transistor (HEMT) are studied and demonstrated. The effects of hydrogen adsorption on device performances such as the threshold voltage shift ΔVth, drain saturation current variation ΔIDS, and transient response are presented. Δ.V th and ΔIDS decreased with increasing operating temperature. This suggests that, at higher temperature, less hydrogen atoms diffuse through the Pt bulk and reach the interface between the Pt metal and oxide layer resulting from the relatively faster formation rate of hydroxyl on the Pt surface. The response curves of the studied Pt-AlGaAs MOS HEMT show various profiles at different temperatures. The influences of hydrogen concentration and temperature on the interface sites occupied by adsorbed atoms are also studied.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)