Design and Investigation of Dual Dielectric Recessed-Gate AlGaN/GaN HEMT as Gas sensor Application

This paper presents a highly sensitive Recessed Gate/source/drain AlGaN/GaN HEMT (RG-AlGaN/GaN HEMT) based Carbon Monoxide gas sensors. Many types of Carbon Monoxide (CO) gas sensor have already been demonstrated experimentally. The deeply etched recessed gate based HEMT form highly sensitive 2DEG for small change in gate metal oxide. Copper Oxide and Cerium Oxide are used as a gate electrode in CO gas detection and these metal oxides are reactively sensitive to CO gas molecules. Because of the change in the work function of gate metal oxide due to the presence of gas deposition on it, there is the change in I-off, I-on, SS and V-th which can be taken as sensitivity parameter for sensing the gas molecules. For a change in work function till 700meV using various steps sizes, RG-AlGaN/GaN HEMT based CO gas sensor shows highly sensitivity with respect to device characteristics parameters.