In0.35Ga0.65As layers were grown on GaAs(1 0 0) substrates by metal-organic vapor phase epitaxy using graded buffer layers. GaAs(1 0 0) substrates misoriented toward (1 1 1)A and (1 1 1)B and exactly oriented GaAs(1 0 0) substrates were used. Surface morphology of InGaAs layers strongly depended on the substrate misorientation direction. The lowest root mean square of surface roughness was obtained for the layer on the substrate misoriented toward (1 1 1)A under optimized conditions. Strain relaxation in InGaAs layers was influenced by substrate misorientation. Threading dislocation densities were 6.4 x 10(6), 3.6 x 10(6), and 2.0 x 10(6) cm(-2) in InGaAs layers on the exactly oriented substrate and substrates misoriented toward (1 1 1)A and (1 1 1)B, respectively. (C) 2002 Elsevier Science B.V. All rights reserved.