Abstract
本實驗以超高真空系統在矽晶片上蒸鍍銅薄膜，經高溫退火後可在矽晶上生成銅矽化物，以此銅矽化物為催化層，研究矽晶在高溫的濕氧化行為。主要使用的分析儀器包括有：穿透式電子顯微鏡，X 繞射儀，及歐傑電子能譜儀，做微結構觀察及相的鑑定。在攝氏150 度做氧化實驗，結果發現矽晶在濕氧中一小時後，氧化層厚度可達3.4 微米，並由乾氧和空氣中的氧化對照實驗，得知高濃度的水氣是使矽晶快速氧化的必要條件。另外，矽晶在攝氏250 到 500 度間的濕氧催化現象，發現其氧化層厚度較150度同時間內的厚度為薄，最大厚度僅為0.85微米；由微結構的觀察，發現在矽晶之上有三層物質：表層為一層較乾淨的二氧化矽，中間大部分是銅矽化物，下層為一層薄的二氧化矽層；氧化層不能進一步長厚的原因是下層的氧化物生成後，減緩了銅原子的擴散，而不能生成新的銅矽化物以催化矽晶氧化。The oxidation of Si catalyzed by Cu3Si at elevated temperatureshas been investigated by transmission electron microscopy, X-ray diffractometry, and Auger electron spectroscopy. The Cufilms were deposited on Si in ultra-high vacuum eletron beamevaporation system. For wet oxidation at 150 C for 1 hr, theoxide layer was grown to 3.4 um in thickness. The presence ofmoisture was found to strongly influence the fast oxidation ofSi. For wet oxidation at 250-500 C, the reaction was found tobe not as fast as that at 150 C. The oxidation reaction wereinitiated at the surface of Cu3Si and Cu3Si/Si interface. Theoxidation reaction at the interface produce an oxide layerbetween copper silicide and Si substrate. The buried oxidelayer acts as a barrier layer for Cu. As a reult, the oxidationof Si was slowed down as the buried layer was formed on top ofSi substrate.