Modified single-phase LPE technique for In 1− x Ga x As 1− y P y laser structures

A modified single-phase technique for growth of epitaxial layers of the quaternary compound, In1−xGaxAs1−yPy has been used to fabricate high-quality laser structures in the 1.3 and 1.55 μm-wavelength range. This method permits the concentration of small amounts of phosphorus in the InGa:As melt to be maintained accurately and independent of the history of the graphite boat. Growth of planar structures having small variations in wavelength and uniformity in layer thickness of the order of hundreds of ångströms was easily repeatable. Laser structures, in addition, had low values for threshold current density and gave high yields for both the 1.3 and 1.55 μm wavelength ranges.