WAVELENGTH TUNING IN STRAINED-LAYER INGAAS-GAAS-ALGAAS QUANTUM-WELL LASERS BY SELECTIVE-AREA MOCVD

Selective-area growth and regrowth using conventional atmospheric pres sure metalorganic chemical vapor deposition is investigated for wavele ngth tuning in strained layer InxGa1-xAsGaAs-AlyGa1-yAs quantum well l asers. Growth inhibition from a silicon dioxide mask is the mechanism used for the selective-area growth rate enhancement. By varying the wi dth of the oxide stripe opening, differences in the growth rate yield different quantum well thicknesses, and hence different lasing wavelen gths for devices on the same wafer. Both two- and three-step growth pr ocesses are utilized for selective-area epitaxy of strained layer InxG a1-xAs-GaAs quantum well active regions, with lasers successfully fabr icated from the three-step growth. Scanning electron microscopy and tr ansmission electron microscopy indicate that the absence of an oxide m ask during AlyGa1-yAs growth is essential for successful device operat ion. A wide wavelength tuning range of over 630 angstrom is achieved f or lasers grown on the same substrate.