Effect of barrier variabilities on the strain propagation and 2DEG profile of GaN/AlGaN HEMT heterostructures

Abstract

This work presents an analysis of strain distribution and depth of 2DEG (2-Dimensional Electron Gas) in AlGaN/GaN HEMT (high electron mobility transistor) heterostructures for different variabilities. In this, we have simulated both single and double-channel HEMT heterostructures. We studied two types of barrier variability: Al mole fraction in the Al <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> Ga <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1−x</inf> N barrier and thickness of barrier on both single and double-channel. It was observed that strain decreases, and the depth of 2DEG increases when mole fraction x in Al <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> Ga <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1−x</inf> N barrier increases for both single and double-channel. Barrier thickness also follows the same trend for both single and double-channel. It was found that the performance of the double-channel heterostructure was better than the single-channel heterostructure in terms of strain distribution and depth of 2DEG formation. We believe that study of the strain distribution of such structures would help the scientific community to design high-performance HEMT-based devices.