Damage-free substrate removal technique: wet undercut etching of semipolar (20(2)over-bar1) laser structures by incorporation of un/relaxed sacrificial layer single quantum well

We applied a damage-free substrate removal technique using photoelectrochemical etching (PECE) by incorporating sacrificial layer In0.12Ga0.88N single quantum well (SL-SQW) types in semipolar (2021 ) flip-chip laser diode (FC-LD) structures. Although 40 nm type I promoted the development of high-quality green active region devices in terms of managing strain relaxation, processing was required under low-temperature KOH. However, 10 nm type II exhibited a smooth n-type GaN surface with room-temperature KOH, thereby promoting the applicability of the proposed technique for either a short light emitter or a combination with type I. The temperature-dependent PECE of SL-SQW types is important in realizing advanced FC-LDs. (c) 2021 The Japan Society of Applied Physics

Automated summary

A damage-free substrate removal technique using photoelectrochemical etching (PECE) was applied in semipolar (2021) flip-chip laser diode (FC-LD) structures by incorporating sacrificial layer In0.12Ga0.88N single quantum well (SL-SQW) types. While 40 nm type I required processing under low-temperature KOH for developing high-quality green active region devices, 10 nm type II exhibited a smooth n-type GaN surface with room-temperature KOH, promoting the applicability of the proposed technique. Temperature-dependent PECE of SL-SQW types is crucial for advanced FC-LDs.