Fabrication of Thin-GaN LED Structures by Au–Si Wafer Bonding

Abstract

Using Au-Si wafer bonding and laser lift-off (LLO) techniques, an light emitting diode (LED) GaN epi layer was successfully transferred onto a Si substrate. After the wafer bonding, a KrF excimer laser was used to separate the GaN layer from the grown sapphire substrate. The Raman spectra results show that the quality of the transferred GaN epi layer did not change; the initial compressive stress level of the GaN epi layer was relieved by 202 MPa after transferring. The transferred GaN epi layer was further processed for use in a thin-GaN LED device. The luminance-intensity-current voltage curve results indicate a forward voltage of 3.4 V, and a luminance intensity of 204 mcd at 20 mA.