An Investigation on the Hydrogen Gas Sensitivity of Silicon Nanowire Devices

Abstract

In this work we investigate feasibility of SiNW for hydrogen gas sensing application. We have used 58μm long p-type silicon NW with source and drain doping and body doping of . This particular structure has been used to resemble fabricated NW platform that has been used to extract the surface states density of SiNW when exposure of gas with pressure of 0.5, 1.0 and 1.5 bar. It is found that 100nm thick SiNW can exhibit sensitivity of gas down to 2500 ppm, 800 ppm, and 100 ppm for pressures of 0.5, 1.0 and 1.5 bar respectively if is exposed on NW in natural ambient. If is exposed on NW in vacuum environment this sensitivity goes down to 200 ppm, 100 ppm, and below 50 ppm respectively for 0.5, 1.0 and 1.5 bar. With the reduction of NW thickness a significant improvement of sensitivity is observed. For 10nm thickness SiNW can exhibit sensitivity of gas down to 500 ppm, 400 ppm, and below 50 ppm for pressure of 0.5, 1.0 and 1.5 bar respectively in natural ambient and in vacuum environment this sensitivity goes down to 100 ppm, 100 ppm, and below 50 ppm respectively for 0.5, 1.0 and 1.5 bar.