Fe/S/GaAs(100)界面形成研究

Interface Formation and Interaction of Fe on S-Passivated GaAs(100)

为了改善界面费米能级钉扎,运用CH3CSNH2/NH4OH对GaAs(100)表面进行钝化,并对界面的形成过程进行研究。结果表明,经高温退火处理后,S在GaAS(100)表面以GaS的形式存在,没有形成化合物;研究了Fe生长过程中的成键特性和电子态,Fe淀积到S/GaAs(100)表面,引起0.5eV的能带弯曲,Fe与Ga、S发生较强的化学反应,而与As的反映被消弱。随着Fe覆盖度的增加,S原子停留在界面处,起到绝缘层的作用,而As和Ga则存在扩散和偏析现象,Fe在S/GaAs(100)表面以岛状形式生长。

We have studied the interface formation and electronic structure of an Fe overlayer deposited on S-passivated GaAs(100). In the first stage of deposition, Fe clusters were formed near S atoms. Compared to Fe/GaAs(100),the sulfur passivation weakens the reaction between As and Fe, which is beneficial to the magnetism at the interface. A magnetic ordering feature could be found at higher coverage due to large exchange splitting .