Light output improvement of InGaN/GaN leds by self-assembled Ag nano-particles and SiNx surface roughening

A method of surface roughening is introduced to the InGaN/GaN LED chip fabrication process by self-assembled Ag nano-particles. 10nm silver film is deposited by E-beam evaporation (EBV) on SiN_x passivation layer and the silver nano-scale particles self-assemble after 400°C Rapid Thermal Annealing (RTA), which are used as the mask for SiN_x Reactive Ion Etching (RIE), and the surface roughness varies with different duration of etching. Test results show that it´s easy and effective to achieve the light output promotion; after RTA for 3min and RIE for 3min, the light output (LOP) is increased by 77.6% under 20mA injection current.