A Nd:YAG high power 532 nm pulsed laser was employed to deposit, a thin layer (30 nm) of palladium onthe gate of a microfabricated gas sensor (MOS capacitor). The functional performances of the MOS devicewere investigated by characterizing the capacitance (C–t, C–V) variations occurring upon H2exposure, asa function of the gas concentration. A comparison in terms of sensor response versus concentration andrecovery time was also performed with sensors in which the Pd layer was deposited by metal evaporation,maintaining all the parameters of the microfabrication process constant and by changing the operativeworking temperature. An improved performance was observed for the laser deposited Pd layer withrespect to the evaporated one, an effect ascribed to the presence of Pd atoms into the underlying siliconoxide layer.
Microfabrication of MOS H2 sensors based on Pd-gate deposited by pulsed laser ablation
Crivellari, Michele;Picciotto, Antonino;Bellutti, Pierluigi;Collini, Amos;Gennaro, Salvatore;
2013-01-01
Abstract
A Nd:YAG high power 532 nm pulsed laser was employed to deposit, a thin layer (30 nm) of palladium onthe gate of a microfabricated gas sensor (MOS capacitor). The functional performances of the MOS devicewere investigated by characterizing the capacitance (C–t, C–V) variations occurring upon H2exposure, asa function of the gas concentration. A comparison in terms of sensor response versus concentration andrecovery time was also performed with sensors in which the Pd layer was deposited by metal evaporation,maintaining all the parameters of the microfabrication process constant and by changing the operativeworking temperature. An improved performance was observed for the laser deposited Pd layer withrespect to the evaporated one, an effect ascribed to the presence of Pd atoms into the underlying siliconoxide layer.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
