Strain mapping of V-groove InGaAs/GaAs strained quantum wires using cross-sectional Atomic Force Microscopy

Cross-sectional Atomic Force Microscopy (AFM) measurements in air combined with finite element (FE) calculations are used to study the (110) cleaved s urface of compressive InGaAs/GaAs quantum wells (QWs) and V-groove quantum wires (QWRs). The elastic relaxation is clearly identified as the main caus e of the AFM height contrast revealed on the cleaved edge. In particular, w e show that the native oxidation due to the air exposure does not alter sig nificantly the elastic deformation of the cleaved surface. This simple tech nique, which does nor require any sample preparation or chemical etching, i s applied to the characterization of the growth front evolution during the organometallic chemical vapor deposition growth on V-grooved substrates. Ma king use of the AFM surface profile measurements evidences the segregation of indium in the InGaAs film. (C) 2000 Elsevier Science B.V. All rights res erved.