Two-dimensional epitaxial growth of strained InGaAs on GaAs (001)

Molecular beam epitaxy growth of lattice mismatched In0.53Ga0.47As / GaAs(100) system is studied by in situ scanning tunneling microscope (STM) and reflection high energy electron diffraction. InGaAs layers with a thickness ranging up to 250 nm do not exhibit a smooth surface when grown under In-rich conditions. RHEED and STM confirm the well-ordered (4x2) reconstruction and mono-layer steps associated with this unique planar growth mode. Large STM scans reveal a characteristic morphology of rectangular shaped islands distributed on large flat terraces which are typically more than 300 nm width but only monolayer steps.