SURFACE STOICHIOMETRY AND MORPHOLOGY OF MBE GROWN (001)GAAS THROUGH THE ANALYSIS OF RHEED OSCILLATIONS

Analysis of RHEED oscillations under static conditions and during MBE growth has been used to study the surface departure from stoichiometry and related microscopic morphology for the As-stabilized 2 multiplied by 4 (001)GaAs surface reconstruction when substrate temperature and arsenic pressure are systematically varied. Specular beam intensities under static conditions are related to the first transient peak and phase shift of the oscillations during growth. Phase shifts are linear with the logarithm of arsenic pressure and depend on substrate temperature with an activation energy of 3. 2 ev in the same way as surface stoichiometry. A discussion of the results based on a surface morphology model is presented.