Fabrication of Mesa Shaped InGaN-Based Light-Emitting Diodes Through a Photoelectrochemical Process

Abstract

InGaN-based light-emitting diodes (LEDs) were fabricated to have a higher light extraction through the photoelectrochemical (PEC) mesa shaping process. After the PEC selective wet oxidation and wet etching processes, stable and controllable crystallographic etching planes were formed as p-type GaN { $$ 10\overline{11} $$ } planes and n-type GaN { $$ 10\overline{1} 0 $$ } planes included at an angle of 27 deg. The ever-present cone-shaped structure of a PEC-treated LED has a larger light scattering area and higher light extraction cones on the mesa sidewall, as analyzed by microphotoluminescence and light output power measurement. This cone-shaped-sidewall LED has a higher light output power and a larger divergence angle compared with a conventional LED measured in an LED chip form.