The Atomic Layer Etching Technique with Low Damage for p-GaN/AlGaN/GaN Structure

In this work, an atomic layer etching (ALE) technique is proposed for p-GaN/AlGaN/GaN. The surface roughness was significantly reduced from 0.5 nm to 0.357 nm, after an ALE process with 15 s O2 modification step and 32 s BCl<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> removal step. Additionally, the oxides product in O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> modification step can be effectively etched or removed. These findings indicate that O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>/BCl<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf>-based ALE technique is a promising approach for fabricating a variety of high-performance GaN devices that contain the p-GaN layer, such as p-GaN Gate HEMTs and GaN p-FETs.