STATIC PHASE-DIAGRAMS OF RECONSTRUCTIONS FOR MBE-GROWN GAAS(001) AND ALAS(001) SURFACES

Static phase diagrams for GaAs(001) and AIAs(001) surfaces have been d etermined using the reflection high-energy electron diffraction techni que. The investigated structures have been grown by molecular beam epi taxy with a Riber 32P machine. Two types of observations of surface re constructions were performed: without any arsenic flux and for variabl e arsenic flux. In the experiments both the substrate temperature and the As, flux were measured directly (the absolute values of the As, fl ux are given in the phase diagrams). On the GaAs(001) surface reconstr uctions (4X2), (3X1), (3X6), (2X4) and (2X2) were observed; on the AIA s(001) surface the reconstructions (3X2), (2X4), (2X2), and (2X3) were seen. The boundaries between different reconstructions have been dete rmined precisely both for the GaAs(001) and the AIAs(001) surfaces. On the basis of the static phase diagrams the values of activation energ ies for phase transitions on the GaAs(001) and the AIAs(001) surfaces have been found. The obtained results have been compared with those al ready existing in the literature.