A Study of Mechanical Lift-Off Technology for High-Efficiency Vertical LEDs Using Micro-Porous GaN Template

Abstract

The high efficiency vertical light emitting diodes (V-LEDs) using mechanical lift-off with Micro-Porous GaN template formed by high temperature molten KOH wet etching process were demonstrated. The average threading dislocation density (TDD) of u-GaN after regrowth was estimated by transmission electron microscopy (TEM) reduced from 2x10(9) to 1x10(8) cm(2). The sapphire substrate was easily removed by mechanical lift-off during wafer bonding process. The light output of V-LEDs are greatly enhanced by 100% compared with Conventional-LEDs at an operating current of 20mA due to the high quality thin GaN and excellent heating dissipation.