GaAs/AlGaAs Diode Lasers on Monolithic GaAs/Si Substrates

摘要

One approach to the development of optical interconnects between Silicon systems utilizes diode lasers fabricated in III-V epitaxial layers grown on Si wafers. We have fabricated double-heterostructure lasers in Gallium Arsenide/Aluminum Gallium Arsenide layers grown on a Germanium-coated Si substrate, and both asymmetric large-optical-cavity (LOC) lasers and graded-index, separate-confinement heterostructure (GRIN-SCH) lasers in such layers grown directly on a Si substrate. The GaAs/A1GaAs layers were grown by molecular beam epitaxy on (100) p-Si substrates. Si and Beryllium were used as the n- and p-type dopants, respectively. Oxide-defined stripe-geometry devices, 300 micro long, were fabricated using standard Gold tin and Chromium gold metallizations for the n- and p-type contacts, respectively. The laser facets were formed by ion-beam-assisted etching. The double-heterostructure devices (8 micro stripe width), in which the active region contained about 10 mole percent A1As, were evaluated using pulsed bias at 77 K. They produced power outputs up to 3.3 mW per facet and exhibited thresholds as low as 170 mA. Keywords: Lasers, Optical Interconnects, Optoelectronic Device.