Ultra-compact, high-yield intra-cavity contacts for GaAs/AlGaAs-based vertical-cavity surface-emitting lasers

A novel method of fabricating compact intra-cavity contacts with high yield for GaAs/AlGaAs-based vertical-cavity surface-emitting lasers is presented. By carefully tailoring the composition of highaluminum content layer, a highly selective Al2O3 etch-stop layer can be formed simultaneously with the oxide aperture during wet thermal oxidation. With this technique, contact metals can be uniformly deposited on deeply embedded contact layers over large substrate areas. Utilizing this embedded etch-stop design, dual intra-cavity contacted three-terminal vertical-cavity surfaceemitting lasers were fabricated, demonstrating submilliampere threshold currents, over 54% differential quantum efficiencies and over 9 mW output powers. VC 2013 American Vacuum Society. [http://dx.doi.org/10.1116/1.4769856]