A Comparative Study of Fabrication of Long Wavelength Diode Lasers Using CCl 2 F 2 /O 2 and H 2 /CH 4

Abstract

ABSTRACT We report comparatively on fabrication of two-section ridge-waveguide tapered 3 quantum well (QW) InGaAsP/InP (1300 nm) and 5 QW AlGaInAs/InP (1550 nm) diode lasers. Gas mixtures of CCl 2 F 2 /O 2 and H 2 /CH 4 were used to form ridge-waveguide on the lasers with InP-based material structures. As known, chlorine-and hydro-carbon based gases are used to fabricate ridge-waveguide structures. Here, we show the difference between the structures obtained by using the both gas mixtures in which surface and sidewall structures as well as performance of the lasers were analysed using scanning electron microscopy. It is demonstrated that gas mixtures of CCl 2 F 2 /O 2 highly deteriorated the etched structures although different flow rates, rf powers and base pressures were tried. We also show that the structures etched with H 2 /CH 4 gas mixtures produced much better results that led to the successful fabrication of two-section devices with ridge-waveguide. The lasers fabricated using H 2 /CH 4 were characterized using output power-current (P-I) and spectral results