低As压退火对GaAs(001)表面形貌与重构的影响

Effect of low As pressure annealing on the morphology and reconstruction of GaAs (001)

在低As压条件下退火处理原子级平坦的Ga As(001)β2(2×4)重构表面.利用扫描隧道显微镜对表面进行研究,发现随着低As压退火时间的延长,表面形貌与表面重构的演变同步进行.表面形貌经历了从有序平坦转变为无序平坦,然后逐渐恢复到有序平坦状态的过程.表面重构则由β2(2×4)重构逐渐转变为(2×6)重构,然后再转变为锯齿状的(2×6)重构,并且表面形貌与表面重构的演变存在一定的相互关系.

In the low As beam equivalent pressure condition, the in-situ annealing treatment is carried out for the previously atomically flat GaAs（001） β2（2×4） reconstruction surface. Utilizing scanning tunneling microscopy, the surface is found to change its morphology simultaneously with the surface reconstruction during the increase of low As beam equivalent pressure annealing time. The surface morphology undergos from ordered flat to disordered flat and then gradually returns to the ordered flat state again. The surface reconstruction turns from β2（2 × 4） to（2 × 6） and then changes to ＂zig-zag＂（2 × 6） state. And there is a correlation between the evolution of the surface morphology and surface reconstruction.