Extremely flat growth-interrupted InAlAs surface grown on a (411)A-oriented InP substrate by molecular beam epitaxy

We investigated flatness of growth-interrupted InAlAs and InGaAs surfaces using In0.53Ga0.47As/In0.52Al0.48As quantum wells (QWs) with well widths (L-w) of 0.6-12 nm grown on a (4 1 1)A-oriented InP substrate by molecular beam epitaxy. In the (4 1 1)A QWs with growth interruption (GI) at the InGaAs/lnAlAs interface (InAlAs surface), full width at half maximum (FWHM) of a photoluminescence peak of the 1.2-nm-thick InGaAs well was as narrow as 15.6 meV, which was almost the same as that of the corresponding well without GI (14.4 meV). On the other hand, the FWHM of the (10 0) QWs with GI at the InAlAs surface was 24.1 meV (L-w = 1.2 nm), which was 55% larger than that of the (4 1 1)A QWs with GI at the InAlAs surface. This result indicates that the effectively atomically flat interfaces [(4 1 1)A super-flat interfaces] are successfully kept in spite of introducing GI, while GI makes the ( 10 0) interface much rough. (C) 2002 Elsevier Science B.V. All rights reserved.