Investigation on a novel SiC Schottky barrier diode hydrogen sensor with trench-insulator structure

Abstract

A novel SiC Schottky barrier diode (SBD) hydrogen gas sensor with trench-insulator structure was proposed in this paper. A physical model is built for this hydrogen sensor based on 4H-SiC SBD thermionic emission theory, tunneling effect of carriers, adsorption/desorption principle of hydrogen and modulation effects of Schottky barrier height. Use Silvaco TCAD, the semiconductor simulation software, to analyze SBDs with trench-insulator layer and to compute current-voltage characteristics at different temperature, hydrogen concentration and trench width under forward bias. The temperature and hydrogen concentration affect the I–V characteristics of the devices by changing the Schottky barrier height. Compared with normal metal-silicon carbide and metal-insulator-silicon carbide devices at 573 K in terms of on-off voltage, current resolution, response speed, and stability, the trench-insulator hydrogen sensor showed good performance. Relationship between device characteristics and trench width was researched using the above model. Trench width has an opposite effect on sensor resolution and sensitivity.

Review of Hydrogen Gas Sensors for Future Hydrogen Mobility Infrastructure

“…However, SiC has been widely studied in devices operating at high temperatures because it has a wide bandgap of 3.3 eV, which is three-fold wider than that of Si, higher thermal conductivity (4.9 W/cm•K), and higher breakdown voltage, as well as contains fewer crystal dislocation defects than other semiconductor materials with a wide bandgap [36]. Qi et al [37] evaluated a SiC Schottky diode hydrogen sensor with a trench-insulator structure; a Pd/Ta 2 O 5 /SiC Schottky diode hydrogen sensor operating at 300 ∘ C with a SiC substrate was also reported [shown in Figs. 3(a)-(c)] [38].…”