M ‐plane InGaN/GaN light emitting diodes fabricated by MOCVD regrowth on c ‐plane patterned templates

Abstract

AbstractIn this work we demonstrate a light emitting diode (LED) with m ‐plane quantum wells fabricated on a (000$ \bar 1 $) template. N‐polar, n‐type GaN was grown by MOCVD on vicinal sapphire substrates. Stripes, measuring 500 nm wide, 500 nm tall and spaced 2 μm apart, were etched parallel to the 〈11$ \bar 2 $0〉 direction leading to sidewalls that are approximately {10$ \bar 1 $0}. Sputtered AlN was used as a regrowth mask on the c ‐plane surfaces. An active region consisting of 5 InGaN quantum wells and GaN barriers followed by p‐type was grown. The regrowth occurred mostly on the exposed m ‐plane sidewalls, leading to lateral growth in the 〈10$ \bar 1 $0〉 direction. The LED was processed using conventional methods. A thick metal contact was used to connect the p‐regions together. Current vs. voltage measurements showed good rectifying behavior with a turn on of about 6 volts. On‐wafer electroluminescence measurements revealed a peak wavelength of 422 nm. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)