,A Novel Oxygen-Based Digital Etching Technique for p-GaN/AlGaN Structures without Etch-Stop Layers

• 作 者: Yang Jiang Ze-Yu Wan Guang-Nan Zhou Meng-Ya Fan Gai-Ying Yang R.Sokolovskij Guang-Rui Xia Qing Wang Hong-Yu Yu
• 机 构: School of Microelectronics, Southern University of Science and Technology, Shenzhen 518055, China“,”
• 出 处: 中国物理快报（英文版）
• 发表日期: 2020年6期

A novel O2 plasma-based digital etching technology for p-GaN/A1GaN structures without any etch-stop layer was investigated using an inductively coupled plasma (ICP) etcher,with 100 W ICP power and 40 W rf bias power.Under 40sccm O2 flow and 3min oxidation time,the p-GaN etch depth was 3.62nm per circle.The surface roughness improved from 0.499 to 0.452nm after digital etching,meaning that no observable damages were caused by this process.Compared to the dry etch only methods with C12/Ar/O2 or BCla/SF6 plasma,this technique smoothed the surface and could efficiently control the etch depth due to its self-limiting characteristic.Furthermore,compared to other digital etching processes with an etch-stop layer,this approach was performed using ICP etcher and less demanding on the epitaxial growth.It was proved to be effective in precisely controlling p-GaN etch depth and surface damages required for high performance p-GaN gate high electron mobility transistors.