It is worth noting that surface corrosion and oxidation may cause local modification of the cleavage surface topography. These processes take place in air and may create individual relief for the layers, as a consequence of their different chemical activity. In fig.a topography of the corroded cleavage is shown. The enhanced corrosion of ZnSe-based layers contrasting stable GaAs surface is evident from the image (see also a height profile in fig.c). Additionally, in comparison with freshly cleaved surface, an undoped waveguide region (W) is resolved as two 100 nm wide stripes. The corrosion of ZnSe-based materials is, however, rather slow under ambient condition, and it takes more than one month to wait single-monolayer-changes in the surface morphology. [2, pdf-file ru]
AFM images are obtained by commercial SPM P4 with CSC12 cantilevers.
On the next pages description of the used lateral force mode and the details of image obtaining are presented. For more information see also paper NN.
Additional information about laser structures were received with usage of Contact EFM, Kelvin mode.