Complementary Metal Oxide Semiconductor-Compatible Top-Down Fabrication of a Ni/NiO Nanobeam Room Temperature Hydrogen Sensor Device

Miniaturized chemical sensors are of immense utility for low-power-consuming, on-chip-integrable functional devices. In this letter, complementary metal oxide semiconductor (CMOS)-compatible fabrication of a suspended Ni/NiO nanobeam gas sensor device showing a selective response to hydrogen gas at room temperature is reported. The dimensions of the suspended Ni beam are 100 nm × 1 μm, and the thickness varied from 15 and 20 nm. Further, it is oxidized using either thermal oxidation or plasma oxidation. The selective response obtained is a nearly 50% change in resistance for 5000 ppm of H2 at 25 °C in plasma-oxidized-sputtered Ni films. The joule heating results in thermal oxidation viz-a-viz electromigration of Ni metal self-functionalization and helps in the selective response toward hydrogen.