ABSTRACT
Growth and processing of heterojunction GaN-based light emitting diodes are described. Multilayer LEDs were fabricated out of p-AlGaN/n-GaN/n-AlGaN on sapphire substrate which were grown using plasma-assisted ionized source beam epitaxy. The growth system utilized high-efficiency radio frequency plasma to generate atomic nitrogen from molecular nitrogen. Ga and Al source beams were partially ionized and accelerated to enhance the incorporation with atomic nitrogen. The turn-on voltage of the LEDs was around 2.5 V and soft breakdown occurred at a reverse bias of around 10 V. At a forward bias of 4 V, the current was 10 mA. The LEDs were stable for a sustained period of time. The light intensity increased linearly with increasing current from 17 to 35 mA and started to saturate around 45 mA. The spectrum showed a peak at the wave length of 518 nm (2.4 eV).
