SURFACE ENGINEERING DURING MOLECULAR-BEAM EPITAXIAL-GROWTH OF WIDE-GAP II-VI STRUCTURES

Systematic investigations have been carried out in order to control the surface morphology of ZnSe and related compounds. Rough surfaces can be smoothed by means of growth interruptions. The smoothing of the surface is reflected in the halfwidth of the intensity distribution along the 00 rod of the reflection high-energy electron diffraction (RHEED) pattern. Reduction of the halfwidth is observed to occur within times of less than a minute; a fast process removes short range disturbances of the surface morphology. A more detailed analysis of the intensity distribution reveals a fine structure. From this, it can be derived that the distance of surface terraces is made uniform during the growth interruption, but this takes several minutes; a slow process removes long range disturbances. Degree and time dependence of surface smoothing are influenced by the beam equivalent pressure ratio during layer growth.