Discrimination of Compound Semiconductor Heterointerfaces by Simultaneous Observations of Atomic Force Microscopy and Lateral Force Microscopy

ZnSe/GaAs heterointerfaces were studied with simultaneous probing by atomic force microscopy (AFM) and lateral force microscopy (LFM). Surface flatness of the (110) cleaved facets was examined with AFM and the frictional force was measured across the heterointerfaces with LFM. On (110) cleaved facets where ZnSe and GaAs surfaces are located on the same horizontal plane with atomic precision and are not distinguishable with AFM, different frictional forces between ZnSe and GaAs surfaces are observed with LFM. This demonstrates the possibility that the geometrical flatness and the difference of semiconductors on cleaved facets of semiconductor heterointerfaces are distinguished with the simultaneous probing of AFM and LFM, respectively. Abruptness of the ZnSe/GaAs heterointerfaces was found to be drastically improved by replacing ZnSe with ZnSe/ZnS0.18Se0.82 superlattices lattice-matched to GaAs.