Nonuniversality in mound formation during semiconductor growth

Abstract
The growth of epitaxial GaAs(100) and InP(100) via molecular beam epitaxy has been characterized in vacuo using scanning tunneling microscopy and a height-height correlation analysis of the resulting images. The GaAs growth characteristics can be changed from a layered to a mounded morphology via a change in the As:Ga flux ratio. For InP growth, mounding is observed for growth on a nominally flat substrate, but layered growth occurs on a vicinal substrate. For both the GaAs and InP cases, the measured growth exponents are different for layered vs mounded growth, and do not conform to the predictions of existing dynamical scaling theories.