Study of an Epitaxial Regrowth Process by MOCVD for Photonic-Crystal Surface-Emitting Lasers
Lih-Ren Chen, Kuo‐Bin Hong, Kuan-Chih Huang, Cheng-Lin Liu, Wei Lin, Tien‐Chang Lu
Abstract
We study a metal organic chemical vapor deposition regrowth process for electrically driven photonic-crystal surface-emitting lasers (PCSELs). The photonic-crystal (PC) structure consisting of air voids embedded in semiconductor materials is fabricated on the topmost p-GaAs layer of a base-epitaxial wafer followed by the regrowth of a p-Al0.45GaAs layer and a p+-GaAs contact layer, consecutively. The effect of both ex situ and in situ surface treatment before regrowth processes together with the regrowth parameters are investigated. The O2 plasma treatment, one of the ex situ treatment process steps, is found to be critical for the surface condition. A flat surface with retained air voids is obtained with proper surface treatment and epitaxial growth condition, and the electrically pumped PCSELs are successfully demonstrated. Moreover, the optimized regrowth condition is also applicable to various PC topologies to enhance the optical output performance.