Initial stages of InP/GaP (100) and (111)A,B grown by metal organic chemical vapor deposition
The initial stages of the three-dimensional metal organic vapor phase epitaxy growth of InP/GaP (100) and (111)A,B were studied by atomic force microscopy (AFM) and Rutherford back scattering (RBS). We have shown that the heteroepitaxial growth takes place under StranskiKrastanov mode (layer by layer and dislocation free island growth). By combining RBS and AFM results, we show that the wetting layer is about 0.51 and 0.4nm for (100) and (111)A,B orientated substrates, respectively. The critical thickness is found to depend on the substrate orientation. However, we show by the AFM technique that the shape, the height and the size of uncapped InP/GaP self-organized nanostructures depend on the amount of InP deposited and on the substrate orientation. In particular, the structure grown on (111)A,B substrate presents higher islands than the structure grown on (100). Therefore, the formation of nanostructures on substrates different from (100) is an interesting possibility to be investigated.
rutherford back scattering heteroepitaxial growth nanostructures atomic force microsocpy