Title :
Tapered air apertures for thermally robust VCL structures
Author :
Naone, Ryan L. ; Coldren, Larry A.
Author_Institution :
Dept. of Mater., California Univ., Santa Barbara, CA, USA
Abstract :
We report on a vertical-cavity laser (VCL) process that allows high-temperature annealing up to 950/spl deg/C for 3 min while minimizing degradation of light-current-voltage characteristics. We used a wet chemical approach to form tapered undercut profiles in buried AlGaAs layers. This two-step process involves AlGaAs multilayers which have been graded to give a tapered oxidation front upon steam oxidation. The second step involves removal of the oxide by a KOH-based solution, keeping the original shape of the oxidized region intact. The air-apertured devices maintained their characteristics after high-temperature annealing while structures with oxide apertures showed a 50% reduction in external efficiency.
Keywords :
III-V semiconductors; annealing; gallium arsenide; indium compounds; molecular beam epitaxial growth; optical fabrication; optical multilayers; quantum well lasers; semiconductor growth; surface emitting lasers; thermal stability; 3 min; 950 C; AlGaAs; AlGaAs multilayers; GaAs; InGaAs-GaAs MQW lasers; KOH-based solution; air-apertured devices; buried AlGaAs layers; external efficiency; high-temperature annealing; light-current-voltage characteristics; second step; steam oxidation; tapered air apertures; tapered oxidation front; tapered undercut profiles; thermally robust VCL structures; two-step process; wet chemical approach; Annealing; Apertures; Degradation; Materials science and technology; Oxidation; Robustness; Shape; Surface emitting lasers; Threshold current; Vertical cavity surface emitting lasers;
Journal_Title :
Photonics Technology Letters, IEEE
