GaAs(001)-(2×6)重构下的表面形貌及其重构原胞  

Morphology and reconstructed unit cell at GaAs(001)-(2×6) surface

作　　者：周勋[1] 罗子江[2] 王继红[3] 郭祥[3] 丁召[3] 

机构地区：[1]贵州师范大学物理与电子科学学院,贵阳550001 [2]贵州财经大学信息学院,贵阳550004 [3]贵州大学理学院,贵阳550025

出　　处：《功能材料》2016年第4期147-151,156,共6页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(60866001);贵州省科学技术基金资助项目(黔科合J字[2014]2046号;[2013]2114号);贵州师范大学2012年博士基金资助项目([2012]001号);贵州省教育厅自然科学研究资助项目(黔教合KY字(2014)265号)

摘　　要：采用RHEED与STM技术对GaAs(001)-(2×6)表面重构下的表面形貌进行研究,研究发现GaAs(001)-(2×6)重构表面是GaAs(001)-β2(2×4)重构表面经530℃,1.33μPa As BEP退火获得,在(2×6)重构下的GaAs(001)表面形貌已经进入表面存在系列单层岛和坑覆盖的无序平坦状态。为了进一步确定(2×6)重构的原胞结构,采用球棍模型对其原胞结构进行模拟,提出新的As表面覆盖率计算方法、结合STM图片分析对球棍模型进行验证和筛选,首次在实验上证实(2×6)重构原胞中存在2个As Dimers和2个Ga Dimers,并以此重构原胞结构构建理论下的(2×6)重构表面,获得结果与STM图片高度吻合。The morphology and reconstructed unit cell at GaAs(001)-(2×6)reconstructed surface were studied using reflection high energy electron diffraction and scanning tunneling microscopy(STM).We found that GaAs(001)-(2×6)reconstructed surface can be obtained annealing the GaAs(001)-β2(2×4)reconstructed surface under 530 ℃ and 1.33μPa As beam equivalent pressure.The morphology at GaAs(001)-(2×6)surface was disordered flat which existed series of islands and pits with 1monolayer height.To clarify the actual structure of GaAs(001)-(2×6),a new method to calculate the As coverage on GaAs(001)surface was proposed and used it to determine the GaAs(001)-(2×6)reconstruction.Combined the STM images and ball-and-stick model to confirm that there were two As dimers and two Ga dimers in a reconstructed unit cell on GaAs(001)-(2×6)surface,then utilized this unit cell to conceive the(2×6)reconstructed surface which was highly consistent with STM image.

关 键 词：GaAs(001)-(2×6)重构 表面形貌 As覆盖率 重构原胞 

分 类 号：TN3[电子电信—物理电子学] O47[理学—半导体物理]