InGaAlAs selective-area growth on an InP substrate by metalorganic vapor-phase epitaxy

With the aim of improving the performances of optical integrated devices, we investigated InGaAlAs selective growth by metalorganic vapor-phase epitaxy. In the case of InGaAlAs selective-area growth (SAG), spike growth at the mask edge did not occur, and the increase in growth thickness and PL peak wavelength at the mask edge are smaller than those in the case of InGaAsP SAG. These results are considered to be due to the high growth temperature and low indium content in the case of InGaAlAs SAG. However, as aluminum content increases, the growth pattern changes. The flatness at the mask edge degrades and the compositional change in the selective region increases by small migration and vapor-phase diffusion lengths for aluminum species. Moreover, in the case of a multiple-quantum-well structure, PL peak intensities for the selective and non-selective regions are similar; thus, even in the case of InGaAlAs SAG, high crystalline quality can be obtained.