No abstract

We address the problem of MBE growth in one horizontal and one vertical direction in the presence of Schwoebel barriers. The time-independent growth equation introduced previously is shown to be identical to that for a classical particle in a potential well. We solve this equation using periodic boundary conditions and find time-independent solutions consisting of a periodic array of mounds. We derive the .dispersion relation., i.e. the amplitude as a function of wavelength for these mounds. The equation of motion is derivable from a free energy indicating that there is a most stable ground state, which is independent of the initial conditions. The mounds are marginally unstable and there is a minimum wavelength below which no mounds exist. The wavelength of the mounds coarsens slowly in time according to At " , with a = 114.

Scanning tunneling microscopy studies have been performed on GaAs homoepitaxial films grown by molecular-beam epitaxy. After an initial transient regime, indicated by reflection high-energy electron diffraction oscillations, the system evolves to a dynamical steady state. This state is characterized by a constant step density and as such the growth mode can be termed generalized step flow.

No abstract

Scanning tunneling microscopy studies have been performed on GaAs homoepitaxial films grown by molecular-beam epitaxy. Images show that in the earliest stages of deposition the morphology oscillates between one with two-dimensional islands and flat terraces. After the initial transient regime, the system evolves to a dynamical steady state. This state is characterized by a constant step density and as such the growth mode can be termed step flow. Comparison with reflection high-energy electron-diffraction (RHEED) shows that there is a direct correspondence between the surface step density and the RHEED specular intensity. Thick films (up to 1450 monolayers) display a slowly-increasing surface roughness. Analysis of the scaling properties and comparison with theories of film growth will be made.