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采用反射高能电子衍射仪与扫描隧道显微镜技术对GaAs(001)-(2×4)表面重构下的表面形貌进行深入研究,获得GaAs(001)薄膜处于不同(2×4)表面重构时的表面形貌。研究发现当GaAs(001)表面处于β2(2×4)时,经过精确控制薄膜的生长、退火以及淬火工艺,GaAs(001)表面能够获得由单一重构组成且原子级平坦的表面形貌;研究结果证实β2(2×4)的表面重构原胞中存在三对As Dimers,其中两对位于重构原胞顶层,一对处于重构原胞次层,这与球棍模型理论下获得的β2(2×4)重构原胞高度吻合;研究发现γ(2×4)表面重构实际上是β2(2×4)重构与C(4×4)重构混合后的重构形式,γ(2×4)重构表面是由大量单层岛和单层坑混合后的无序平坦表面;α(2×4)存在的温度区间很窄,它是GaAs表面从富As状态到富Ga状态转变的过渡重构形式,实验中将很难获得单一α(2×4)重构相表面。
The surface topography of GaAs (001) - (2 × 4) surface was investigated by means of reflection high-energy electron diffraction and scanning tunneling microscope. The surface reconstruction of GaAs (001) When the surface morphology. The results show that the GaAs (001) surface can be obtained by a single reconstitution and atom level planar surface morphology when the GaAs (001) surface is at β2 (2 × 4) and the growth, annealing and quenching process of the GaAs (001) The results confirmed that there are three pairs of As dimers in β2 (2 × 4) surface reconstructed cells, two of which are located in the top of reconstructed cells and one in the sub-layer of reconstructed cells, which is obtained with the club model theory Β2 (2 × 4) reconstructed cells were highly consistent. It was found that the γ (2 × 4) surface remodeling is actually the reconstructed β2 (2 × 4) remodeling and C (4 × 4) remodeling The γ (2 × 4) reconstructed surface is a disorderly flat surface composed of a large number of monolayers and monolayers. The α (2 × 4) temperature range is very narrow, To the transition reconstruction of Ga-rich state, it will be very difficult to obtain a single α (2 × 4) reconstructed surface in the experiment.