Ammonium Sulfide Passivation for AlGaAs/GaAs Buried Heterostructure Laser Fabrication Process

Abstract
We have introduced ammonium sulfide ((NH4)2S x /(NH4)2S) treatment to reduce the surface recombination in the regrowth process of an AlGaAs/GaAs buried heterostructure (BH) laser by MOCVD. The (NH4)2S x -treated BH lasers showed much lower threshold current than BH lasers without the chemical passivation. This fabrication technology is expected to be very effective for the realization of ultralow-threshold micro-cavity lasers with a few-micron or submicron cavity structure.