The Study On Expitaxial Growth Technology Of GaN Based LED

Featured by energy-saving, eco-friendly, fast response and small volume, LEDs based on GaN have been widely used ever since their coming out, meanwhile, its reliability has also drawn much attention. In this paper, the brightness and ESD reliability are improved through a serial of MOCVD experiments. The main work and achievements are as follows:1.The effect of doping concentration for n-type and p-type GaN on crystallization quality and LED optical properties is experimentally studied, through which the dopant flow is optimized.2.The temperature during the growing of quantum well is changed, and the optical quality and quantum well crystallization quality are analyzed by PL spectrum and XRD respectively.3.The p-AlGaN layer growing temperature is optimized, followed by PL spectrum and photoelectron tests on LED epitaxial layer, and it is found that LEDs exhibit the best optical properties with the barrier layer temperature 960℃.4.The InGaN/InGaN multi quantum well is introduced and analyzed by XRD(002) curve swing test, finding that after the doping of In into barrier layer, less dislocation faults are found in the quantum well, resulting a better interface quality. Meanwhile, PL and photoelectron tests show that In-doped barrier layer have a heavier light emission. Human body model of ESD test shows the decrement of dislocation faults in quantum wells helped decrease the leaking channels, resulting a better ESD reliability.5. LEDs grown on PSS and ordinary sapphire substrate are compared, peak width at half height in the XRD swing curve for GaN (002) and (102) face on PSS samples are both greatly decreased. The optical qualities and ESD reliabilities are also dramatically improved.