GaN Heterostructure-Based MOSHEMT with an Embedded Cavity for Neutral Biomolecule Detection

This paper presents a GaN-based Metal-Oxide-Semiconductor High-Electron Mobility Transistor (MOSHEMT) integrated with an embedded cavity to detect neutral biomolecules. On the drain side, under the gate, the cavity structure is formed with a length of 500 nm and a depth of 7 nm. The embedded cavity eliminates the need for a reference electrode. The study employs a dielectric modulation approach within the cavity area to replicate the effects of various dielectric biomolecules. The sensitivity of the biosensor to a specific biomolecule is analyzed by examining the changes in the drain current (∆I<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DS</inf>) and threshold voltage (∆V<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</inf>) with reference to the empty cavity i.e air with a dielectric constant of 1. The MOSHEMT biosensor device structure has been simulated using ATLAS Silvaco simulation tool. The biomolecule kertain has exhibited the highest change of 1.42 V in V<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</inf> and 125 mA/mm in I<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DS</inf>.