InAs(001)吸附表面的不可逆重构相变研究

A-s Adsorbed InAs( 001) Surfaces and Its Irreversible Reconstruction Phase Transition

对吸附了大量As的InAs（001）样品进行升降温热处理，发现在485℃时表面有从（3×1）重构到（2×4）重构的不可逆转变现象。利用扫描隧道显微镜对（3X1）重构表面分析，结果表明大量常温吸附的As从表面脱附使InAs（001）（2×4）重构表面最顶层的Asdimer也一起脱离表面，（3×1）重构表面实际上是由20％的富As（2×4）重构区域与80％的富In（4×2）重构区域组成。不可逆相变是由于As束流提供的As4原子团吸附到富In区域，使样品表面恢复N（2×4）重构相，而（2X4）蓖构相能在390～490℃温度范同内稳定存在。

For the lust tirre,the irreversible phase transition from （3 × 1） to （2 ×4） reconstructions was observed at 485℃ on the As-adsorbed,InAs （031） surfaces in the heating-up and cooling-down process.The （3 ×1） reconstructed InAs（031） surface was characterized with scanning tunneling microscopy （STM）,and reflztion high energy electron diffraction. The results show that the thermal desorption of a large number of the As atoms,adsorbed at room temperature on the InAs （1301） surfaces,drogged with them quite a few As-dimers away from the （2× 4） reconstructed surfaces. In fact, the （3 × 1 ） reconstructed surfaces include 20% As-rich （2 × 4） reconstruction and 80% In-rich （4 ×2） reconstruction.The irreversible phase transition originated from the adsorption of the As4 clusters of the As-beam on the In-rich area, resulting in the （2× 4） reconstruction. We found that the （2 × 4） reconstruction was fairly stable in the 390- 490℃ range.