MOVPE Growth of Antimonide-containing Alloy Materials for Long Wavelength Applications

GaAs-based heterostructures comprised of GaAs1-xNx-GaAs1-ySby (x<0.03, y<0.35) multiple quantum wells (MQW) that utilize ‘W’-shaped type II transitions have potential for realizing high-performance monolithic VCSELs and low temperature-sensitivity edge-emitting lasers in the 1.55 μm wavelength region. MOVPE growth of GaAsSb is complicated by both thermodynamicly driven phase separation and kinetic effects that arise from incomplete thermal decomposition of methyland hydride precursors at typical growth temperatures. The impact of growth chemistry on the formation of strained and pseudomorphic films was studied through the growth of relaxed GaAsSb films and multi-period pseudomorphic GaAsSb/GaAs superlattices. Trimethyland triethylgallium and trimethyland triethylantimony were used in a variety of combinations. The observed variations of the Sb incorporation efficiency for relaxed and strained films with growth conditions are not predicted by the existing thermodynamic models of the growth, indicating a coupling of the surface growth chemistry and the strain-induced changes in the surface stoichiometry. Through modification of the growth chemistry and process conditions an extended range of Sb incorporation was realized as well as enhanced control over the alloy * Electronic Address: [email protected] Ac ce pt ed m an us cr ip t 2 composition in strained layers. These achievements lead directly to an extended wavelength range in type II MQW structures.