90° double reflection high-energy electron diffraction experiments on vicinal surfaces of GaAs

Reflection high-energy electron diffraction (RHEED) experiments recording the intensity of the specular beam in two azimuths have been carried out simultaneously. The critical temperature for the transition from 2D nucleation to step-flow growth was simultaneously estimated in the [10] and [110] directions by observing the disappearance of RHEED intensity oscillations on GaAs(001) substrates 2° misoriented towards GaAs(111)A. It was found that the oscillations disappear at a lower substrate temperature in the [110] azimuth. The difference in the transition temperatures was 25°C.