水素終端および酸化Si(100)上Geの固相エピタキシャル成長

Abstract

Thin Ge films with thickness about 10 nm were deposited on hydrogen-terminated and oxidized Si(100) surfaces using electron beams. The above two types of surfaces by chemical treatments and measured the amounts of oxygen and hydrogen by ion channeling and nuclear resonant reaction of H-1(N-15, alpha gamma)C-12, respectively were prepared. They were estimated to be 1.2 nm (SiO2) and 0.9 x 10(exp 15) H/sq cm (1-2 monolayers). The samples were post-annealed at 600, 800, 900 and 1000 C for 5 s in a high vacuum. The hydrogen-terminated Si(100) has a strongly stable hydride structure, which remains at the Ge/Si interface up to 900 C. This very thin and stable Si-hydride surface brings significant effects to improve the surface morphology and crystallinity and to hold steep interfaces compared with the oxidized surface.

厚さ約10nmのGe薄膜を水素終端および酸化Si(100)表面上に電子ビームを用いて蒸着させた。化学処理によって上記の2つの型の表面を作り、酸素と水素の量を各イオンチャネリングとH-1(N-15,αγ){12}Cの核共鳴反応によって測定した。1.2nm(SiO2)と0.9×10{15}H／平方センチメートル（1-2単分子層）と推定した。試料は高真空で5秒、600,800,900および1000度Cで後熱処理した。水素終端Si(100)は非常に安定な水素化物構造をもち、Ge/Si界面に900度Cまで存在する。この薄膜と安定なSi水素化物表面は、表面モルフォロジーと結晶化度の改善と酸化された表面に比べて急勾配界面保持とに著しい効果をもたらす。