| Summary: | 碩士 === 國立臺北科技大學 === 光電工程系研究所 === 101 === Due to the more benefits with flexible substrate, this study is to research the technology of the fabrication of thin film GaN light emitting diodes (GaN LEDs) which transferred from sapphire to flexible substrate. In this projects, The LED structures were fabricated by using MOCVD and then it is separated from sapphire substrates by laser lift-off (LLO) after device bonding to substitute substrate. Then, the structure was transferred to stainless steel foil (SSF) and made the boundary ohmic contact by means of Ag glue. In addition, photoluminescence (PL) measurement demonstrates the emitting wavelength at 365 nm and 450 nm respectively which was no changed before and after transferring to flexible substrate and also manifested illuminating blue light. From current–voltage characteristics, the forward voltage had essential decrease to 3.38V about 4.8%. Besides, it was observed the impact of stress on multiple quantum well (MQW) was changed by bending and it also made the spectrum blue shift.
Over and above substrate transferring, it used RF reactive magnetron sputtering to grow Ni film and then forms Ni nanodot by rapid thermal annealing (RTA) above LED device so as to be the etching mask. By Inductive Couple Plasma (ICP) etching, it roughed GaN surface to release stress from the interior of LED which resulted in photoluminescence spectrum blue shift.
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