DYNAMICS AND ROUGHNESS SPECTRUM OF THE GAAS(001) SURFACE DURING THE MBE PROCESS

The roughness spectrum of the GaAs(001) surface has been studied during growth and after growth interruption by combining the time-dependent recording of the RHEED specular beam intensity with intensity profile measurements of the specular streak. The profiles reflect drastic changes in the distances of Ga-terminated steps in [110BAR] direction, the roughness of As-terminated steps in [110] direction, and the number of levels included in the surface profile. The rates of the underlying kinetic and thermodynamic processes are estimated from the recovery of the specular beam intensity which shows a stepwise increase for growth interruptions after extended deposition.