Post dry etching treatment of nanopillar GaN/InGaN multi-quantum-wells

摘要: Abstract Time-resolved photoluminescence (PL), current-voltage characteristics and deep trap spectra of nanopillar GaN/InGaN multi-quantum-well (MQW) light emitting diodes (LEDs) prepared by reactive ion etching (RIE) from planar samples were studied as a function post-RIE surface treatment. Immediately after RIE, we observe sharp drop intensity the 460 nm MQW PL band strong increase defect-related 600 nm similar to yellow in n-GaN. KOH (NH4)2S sulfur passivation treatments increased above level structure decreased defect band, but was not effective decreasing RIE-induced excessive leakage current LEDs. Only annealing at ≥ 700 °C following RIE able strongly suppress leakage. Deep suggest that are accompanied Ec-0.7 eV electron density Ev+0.8 eV hole quantum wells. The first these defects is attributed nitrogen interstitial acceptors believed be nonradiative recombination centers, while traps gallium vacancy acceptor complexes with shallow donors. Both types produced on sidewalls nanopillars can largely annealed 700 °C, although higher temperatures needed fully their negative impact. These results also relevant curing effects dry-etch damage for micro-LEDs small chip dimensions, serious problem micro-LED field.