Observation of Fine Compositional Fluctuation in GaAs/AIxGa1-xAs Superstructure Using Composition Analysis by Thickness-Fringe (CAT) Method

Abstract
The fine compositional fluctuation in a GaAs/Al x Ga1-x As superstructure grown by metal-organic chemical vapor deposition (MOCVD) was evaluated by using the composition analysis by thickness-fringe (CAT) method. A sinusoidally oscillating Al composition in the growth direction was observed to have a period of 1∼4 nm and in the range x=0.15 to 0.5. The CAT method was successfully applied to measure such fine compositional fluctuations with a high spacial resolution.