Improving properties of GaInNAs with a short-period GaInAs/GaNAs superlattice

Short-period superlattices of GaInAs/GaNAs were grown by gas-source molecular beam epitaxy. Hall measurement shows that the electron mobility is improved by a factor of almost two. The photoluminescence (PL) intensity is improved by rapid thermal annealing. The PL intensity for digital alloys is 2.5 to 3 times higher than that of the random alloy at room temperature, and the improvement is even greater at low temperature (10 K) by a factor of about 12. The optimal annealing temperature was investigated from 650/spl deg/C to 900/spl deg/C. High temperature (above 850/spl deg/C) annealing causes In and N interdiffusion and forms GaInNAs at the superlattice interface. The PL spectrum shows separation between the quantum confined level and the GaInNAs state.