Selective Deposition of PdO Nanoparticles on Si Nanodevices for Hydrogen Sensing

In this paper, we present a method, involving plasma-enhanced atomic layer deposition and constant-power device-localized Joule heating (DLJH), for the selective deposition of palladium oxide (PdO) nanoparticles at the n– region of n+/n–/n+ polysilicon nanobelt (PNB) devices. These PdO-decorated PNB devices were then operated under DLJH so that the temperature of the n– region was maintained during the sensing of H2 gas. From their measured responses, the devices operated at a temperature of 339 K exhibited the most reactive interactions between PdO and H2. Considering the possibility of humidity interference, we also characterized the PdO-decorated PNB devices for H2 sensing at various relative humidities. The PdO nanoparticles on the PNB devices having a grain distance that sustained a spillover effect were almost immune to RH interference.