Cross-sectional scanning tunneling microscopy study on II-VI multilayer structures

Cross-sectional scanning tunneling microscopy is used to study in the atomic scale the structural properties of ZnSeTe/ZnTe multiple quantum wells and N:ZnTe delta-doped structures. Some peculiar effects are found on the cleaved (110) ZnTe surface plane, which have not been observed in III-V semiconductors. In particular, cleavage induced monatomic wide vacancy chains are always present on the Te sublattice. Furthermore, the semiconductor surface is manipulated when certain positive voltages are applied to the sample. Regarding the heterostructures, the ZnSeTe/ZnTe quantum wells are found to have abrupt interfaces and the Se concentration is determined to be significantly larger than the nominal value. (C) 2007 American Institute of Physics.