Ahn H, Wu C L, Gwo S, Wei C M, Chou Y C
Department of Physics, National Tsing-Hua University, Hsinchu, Taiwan 300, Republic of China.
Phys Rev Lett. 2001 Mar 26;86(13):2818-21. doi: 10.1103/PhysRevLett.86.2818.
A comprehensive atomic model for the reconstructed surface of Si3N4 thin layer grown on Si(111) is presented. Kikuchi electron holography images clearly show the existence of adatoms on the Si3N4(0001)/Si(111)-(8x8) surface. Compared with the ab initio calculations, more than 30 symmetry-inequivalent atomic pairs in the outmost layers are successfully identified. Scanning tunneling microscopy (STM) images show diamond-shaped unit cells and nine adatoms in each cell. High-resolution STM images reveal extra features and are in good agreement with the partial charge density distribution obtained from total-energy calculations.
本文提出了一个用于在Si(111)上生长的Si3N4薄层重构表面的综合原子模型。菊池电子全息图像清楚地显示了Si3N4(0001)/Si(111)-(8x8)表面上存在吸附原子。与从头算计算相比，成功识别出了最外层中30多个对称不等价的原子对。扫描隧道显微镜（STM）图像显示出菱形晶胞，每个晶胞中有九个吸附原子。高分辨率STM图像揭示了额外的特征，并且与从总能计算得到的部分电荷密度分布非常吻合。
