GRINSCH GAINASP MQW LASER STRUCTURES GROWN BY MOMBE

For applications in long wavelength MQW lasers, GaInAsP/InP heterostru ctures were grown by metalorganic molecular beam epitaxy (MOMBE or CBE ). The growth process was performed with all gaseous sources for group III, group V and dopant precursors. In addition to the standard strai ned MQW laser structure with two quaternary separate confinement layer s on each side of the active MQW region, laser structures with continu ously graded GaInAsP confinement layers (GRINSCH) were prepared. In th e latter case all group III and group V flows were ramped synchronousl y while maintaining lattice matching growth conditions. By this method a parabolic variation of the band gap was obtained. Data from first t est lasers are comparable to those from standard lasers revealing the high material quality of MOMBE grown InP-based GRINSCH structures. Bes ides standard strained quaternary layers InAsP layers with compressive strain up to 2% were used as quantum wells, and InAsP MQW lasers with emission wavelengths of both 1.3 and 1.55 mu m were fabricated. Moreo ver, an excellent MQW wavelength uniformity (standard deviation Delta lambda less than or equal to 2 nm) across areas larger than 95% of a 2 '' wafer along with proven thermal stability demonstrates the high yi eld of the process for all structures revealing the feasibility of thi s material for industrial use. (C) 1998 Elsevier Science B.V. All righ ts reserved.