Unique surface structure formation on a Ge-covered Si(110)-162 surface

Ge蒸着Si(110)-162表面の新規構造形成

横山 有太*; 魚住 雄輝; 朝岡 秀人  

Yokoyama, Yuta*; Uozumi, Yuki; Asaoka, Hidehito

Si-Ge系のナノ構造をSi(110)-162表面に作製し、低次元構造の作製を試みた。蒸着量に応じて、新規のナノドット生成や、Si-Ge層による新規の表面再配列構造を見出した。特にSi-Geの表面再配列構造は1次元鎖を持ち、Geの濃度に応じて1次元鎖間の距離を自在に制御できる可能性を示した。

Si-Ge structures forming new shapes on a Si(110)-162 reconstructed surface were investigated via scanning tunneling microscopy. Pyramidal-shaped Si-Ge nanoislands lying along the 1 1 1 directions were formed on the striped structure at Ge coverage between 3 and 6 monolayers. However, when a single monolayer of Ge was deposited on the Si(110)-162 surface, single-domain of 162 striped structure disappeared, and a new double-domain striped structure was formed over the surface along directions that differed from the 1 1 2 directions. This structure represents a new Si-Ge striped structure that forms by the mixing of Ge and Si due to high temperature annealing. These results indicate that the surface structure changes specifically with trace amounts of Ge.