Microscopic structural properties of CdSc/ZnSe single quantum wells grown on vicinal GaAs substrate are investigated by cross-sectional high-resolution transmission electron microscope. The interface of ZnSe buffer and GaAs substrate, the surface of top ZnSe, and CdSe well Lire observed. At the ZnSe/GaAs interface, the lattice structure is strongly smeared, indicating that structures other than ZnSe and GaAs are formed. Stacking faults are generated at this region. A distinct step and terrace structure is observed at the surface of top ZnSe. The averaged terrace width coincides with the nominal value of 5degrees vicinal surface. Well layer is tilted with regard to the (200) lattice plane by 50, and no misfit dislocation is found. Strain mapping of the obtained lattice image is performed. (C) 2002 Elsevier Science B.V. All rights reserved.