本論文將探討矽在銀(111)表面上，控制基板溫度及改變矽的鍍率，其表面重構隨矽（Si）覆蓋量增加之變化。我們在超高真空的環境下，透過直流電加熱方式產生矽蒸氣，使其吸附於加熱的銀(111)表面上，並利用X光光電子能譜術（X-ray Photoemission Spectroscopy, XPS）與低能電子繞射（Low Energy Electron Diffraction, LEED）來研究矽在銀(111)表面上隨蒸鍍時間增加之結構變化。以高鍍率鍍了少量的矽以後，透過低能量電子繞射觀察到(4×4)與(√13×√13)R13.9°的重構同時存在。隨著鍍矽量增加，當表面覆蓋超過一個原子層(1ML)的矽之後，新的(4/√3×4/√3)R30°重構產生，並越來越顯著，而原本存在的(4×4)與(√13×√13)R13.9°重構則越來越不明顯。另外，為了探討是否真實有矽(4×4)單一結構存在於銀(111)表面上，我們試著以極緩慢的鍍率在銀基板上鍍矽，發現表面覆蓋少量的矽時，由低能量電子繞射成功觀察到(4×4)單一重構，並隨著表面覆蓋的矽增加，(√13×√13)R13.9°重構開始逐漸形成，其表面結構的變化與高鍍率之結果一致。我們也利用X光光電子能譜術，量測到兩種不同矽2p的電子態，隨著矽覆蓋量增加，觀察到不同電子態消長的現象。不論是高鍍率還是低鍍率，在覆蓋一個原子層以前，兩種電子態皆以固定的比例增加，約超過一個原子層厚之後，才開始各自有不同的轉折變化，由趨勢推測是矽-矽與矽-銀兩種化學態的變化結果。矽在銀(111)基板之重構，透過低能量電子繞射來了解表面原子排列情形，同時結合矽2p和銀3d電子能譜來分析表面原子分布的趨勢。本論文亦根據上述結果，檢視了可能的原子結構模型。;We have studied the superstructures of Si on Ag(111) grown with varied Si coverages and substrate temperatures. The surface reconstructions of Si/Ag(111) were characterized with X-ray photoelectron spectroscopy (XPS) and low energy electron diffraction (LEED). The (4×4) and(√13×√13)R13.9°reconstructions were observed for the Si coverage of one monolayer; the (4/√3×4/√3)R30° reconstruction would emerge with further Si deposition. With a low rate of deposition of Si, the surface showed a single (4×4) reconstruction initially, and became the combination of several reconstructions as the Si coverage was increased. With a high rate of deposition, the single (4×4) phase was not observed. The evolution of the core levels Si 2p and Ag 3d was measured and analyzed with an increasing Si coverage. Combining the results of XPS and LEED, the possible atomic models for the different surface reconstructions were proposed.
