InAs Quantum Dot Lasers With Dry Etched Facet by Br-Ion Beam-Assisted Etching

The etching conditions of the AlGaAs materials in bromine ion beam-assisted etching (Br-IBAE) process have been determined. The etching rates can be varied from several nm/min to ~300 nm/min through controlling the bromine pressure and the substrate temperature. High-performance InAs quantum dot (QD) lasers have been grown by molecular beam epitaxy system. The broad area QD lasers are fabricated by standard photolithography and metallization processes, while the laser facets are formed by Br-IBAE dry etching process. With the dry-etched facets, the InAs QD lasers have a threshold current density Jth, and slope efficiency, η
_i
of 480 A/cm
²
and 34%, respectively. The Br-IBAE dry etched facet reflectivity of 0.28 is obtained from fitting the J
_th
versus reciprocal cavity length curves.