Abstract: The mound formation during molecular beam epitaxy of InP with variations of growth temperatures and Ⅴ/Ⅲ beam equivalent pressure (BEP) ratios is studied by means of atomic force microscopy. Three-dimensional (3D) mounds are observed in two kinds of growth conditions. One is at low growth temperature, the origin of mound formation can be attributed to an intrinsic growth instability of a singular surface in the presence of so-called Ehrlich-Schwoebel (ES) step-edge barrier, which inhibit the downward movement of adatoms at surface step-edges. The other is at high temperature, or at low Ⅴ/Ⅲ (BEP) ratio, the reason of mound formation is related to phosphorus deficiency. Under suitable growth conditions, two-dimensional (2D) layer-by-layer growth can be obtained.

Key words: The mound formation during molecular beam epitaxy of InP with variations of growth temperatures and Ⅴ/Ⅲ beam equivalent pressure (BEP) ratios is studied by means of atomic force microscopy. Three-dimensional (3D) mounds are observed in two kinds of growth conditions. One is at low growth temperature, the origin of mound formation can be attributed to an intrinsic growth instability of a singular surface in the presence of so-called Ehrlich-Schwoebel (ES) step-edge barrier, which inhibit the downward movement of adatoms at surface step-edges. The other is at high temperature, or at low Ⅴ/Ⅲ (BEP) ratio, the reason of mound formation is related to phosphorus deficiency. Under suitable growth conditions, two-dimensional (2D) layer-by-layer growth can be obtained.