Area selectivity of InGaAsP-InP multiquantum-well intermixing by impurity-free vacancy diffusion

Area selectivity of bandgap tuning in the InGaAsP-InP multiquantum-well structure has been investigated using low temperature photoluminescence (PL). The bandgap blue-shift in the intermixed region was as much as 170 meV for a rapid thermal anneal of 30 s at 850°C, and was controllable using annealing temperature and time. From samples with SiO₂ stripe patterns, clearly separated PL peaks were observed centered at 0.95 and 1.08 eV, each representing signals originating from the dielectric capped and exposed areas, respectively. In samples with stripes intervals less than 6 μm, PL signals did not separate, but formed one broad spectrum due to lateral diffusion. The lateral diffusion was found less than 3.0 μm