GROWTH OPTIMIZATION OF GAXIN1-XASYP1-Y GAAS(0.98 MU-M) QUANTUM-WIRE HETEROSTRUCTURES/

The strain-induced lateral-layer ordering technique has proven itself to be a viable method for creating quantum wires (QWRs) via molecular beam epitaxy. In an effort to achieve emission at the technologically important 0.98 mu m wavelength, GaxIn1-xAsyP1-y QWRs formed on on-axis GaAs substrates using (GaP)(m)/(InAs)(n) short-period superlattices ( SPS) are investigated. The growth parameters, such as the growth tempe rature, the source switching pause scheme, and the group-V source flow sequence are optimized to create QWRs with emission near 0.98 mu m. F or structures utilizing abrupt switching between constituent layers, i t was determined that the optimal temperature at which to grow the (Ga P)(22)/(InAs)(1) SPS on GaAs was 480 degrees C. By introducing pause t imes and additional group-V source coverage to the growth scheme, the quality of the QWR heterostructure is markedly improved. The existence of a lateral composition modulation in the growth plane is evidenced by the low-energy emission (redshift) with respect to the bulk GaxIn1- xAsyP1-y, and the highly polarized nature of the photoluminescence (PL ) spectra. Furthermore, the effects of the barrier material between QW R layers (in the growth direction) on the temperature stability of PL peak wavelengths near 0.98 mu m were studied. The temperature induced wavelength shift depends on the barrier material, barrier thickness, a nd the composition of the SPS used in the QWR region. A minimum PL pea k wavelength shift of about 200 Angstrom between 77 and 300 K was obse rved in the GaxIn1-xAsyP1-y QWR system with Ga0.51In0.49P barriers. (C ) 1998 American Vacuum Society.