Misorientation effect on the monolayer terrace topography of (100) InP substrates annealed under a PH3/H2 ambient and homoepitaxial layers grown by metalorganic chemical vapor deposition

Abstract

The detailed monolayer terracelike topography of nominal on-axis and misoriented vicinal (100) InP surfaces was systematically investigated by ‘‘ex situ’’ atomic force microscopy. Vicinal (100) InP reconstructs into steps around 550 °C in either argon or phosphine/hydrogen. Widths of observed monoatomic terraces are measured to be in close agreement with misorientation angles. Homoepitaxial growth by metalorganic chemical vapor deposition preserves the terracelike structure. Growth acts through a monoatomic step flow mode following the classical Burton–Cabrera–Frank theory. Surface diffusion length is estimated up to 350 nm in our standard growth conditions at 630 °C and 2.5 μm/h. Spiral growth is also observed and takes its origin from a screw dislocation emerging on the surface of the substrate. The critical misorientation angle below which the spiral growth mechanism occurs and competes with the vicinal steps is in the range of 0.05°–0.1°.