A novel O 2 plasma-based digital etching technology for p-GaN/AlGaN 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 40 sccm O 2 flow and 3 min oxidation time, the p-GaN etch depth was 3.62 nm per circle. The surface roughness improved from 0.499 to 0.452 nm after digital etching, meaning that no observable damages were caused by this process. Compared to the dry etch only methods with Cl 2 /Ar/O 2 or BCl 3 /SF 6 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 ...

中文翻译：

---

无蚀刻停止层的p-GaN / AlGaN结构的基于氧的新型数字蚀刻技术

使用电感耦合等离子体（ICP）蚀刻机，以100 W ICP功率和40 W rf偏置功率，研究了不带任何蚀刻停止层的p-GaN / AlGaN结构基于O 2等离子体的新型数字蚀刻技术。在40 sccm O 2流量和3分钟的氧化时间下，p-GaN蚀刻深度为每圈3.62 nm。数字蚀刻后，表面粗糙度从0.499纳米提高到0.452纳米，这意味着该工艺不会引起可观察到的损坏。与使用Cl 2 / Ar / O 2或BCl 3 / SF 6等离子体的仅干法刻蚀方法相比，该技术可平滑表面，并且由于其自限制特性，可以有效地控制刻蚀深度。此外，与具有蚀刻停止层的其他数字蚀刻工艺相比，这种方法是使用ICP蚀刻机进行的，对外延生长的要求较低。