Depth profiling of the dry-etching damage in n-type GaN induced by inductively coupled plasma reactive ion etching was carried out by cyclical electrochemical impedance spectroscopy (EIS) measurements and damage-free photo-electrochemical (PEC) etching. The GaN samples were dry-etched under different etching bias power ( P bias ) conditions, and PEC etchings were conducted in increments of 10 nm after EIS measurements. The damage depth was determined to be less than 50 nm for the sample corresponding to P bias = 30 W and was less than 10 nm for the two-step etching sample corresponding to P bias = 30 W + 5 W.

中文翻译：

---

使用光电化学技术感应耦合等离子体反应离子刻蚀在n型GaN中引起表面损伤的深度剖析

通过循环电化学阻抗谱（EIS）测量和无损光电化学（PEC）蚀刻，对电感耦合等离子体反应性离子蚀刻引起的n型GaN中的干蚀刻损伤进行了深度剖析。在不同的蚀刻偏压功率（P bias）条件下对GaN样品进行干蚀刻，在进行EIS测量后，以10 nm的增量进行PEC蚀刻。对于对应于P bias = 30 W的样品，确定损伤深度小于50 nm，对于对应于P bias = 30 W + 5 W的两步蚀刻样品，其损伤深度小于10 nm。