- 學位論文
室溫下鋁在Si(111)晶面成長模式與原子結構
Growth Mode of Al Films on Si(111) Surface at Room Temperature
摘要
近年來在半導體產業中，單層以及數個原子層的二維材料逐漸受到重視，在半導體基板上生長金屬薄膜(Ultra thin film)的製程備受關注。常見的系統有Al/Si，而目前2004年，劉洪(Hong Liu)等人，進行低溫下(145 K)在Si(111)基板上成功成長出鋁薄膜，此實驗的目的希望可以在常溫下成長出鋁的薄膜。 實驗中藉由分子束磊晶(Molecular beam epitaxy)將鋁在沉積在Si(111)表面，接著進行熱退火(post-annealing)處理，並利用掃描穿隧電流顯微技術探測表面形貌以及原子排列方式，最後以SPIP分析軟體以及python進行模擬分析。 在實驗過程中我們嘗試改變室溫(300 K)蒸鍍鋁層數(Al coverage) 0.8 ML, 1.7 ML以及 3.0 ML，再進行不同溫度的熱退火(annealing)處理於230 °C以及350 °C。雖然沒有成長出理想的鋁薄膜，不過我們成長出有序排列的覆蓋層(overlayer)，並對Al(100)以及Al(111)二維鋁島進行進一步的探討。 覆蓋層(overlayer)主要有二種情況一種為 Al(√3×√3)R30°結構，另一種保持跟Si(111)基板平行的方向，我們認為可能是Al(2×2)，或者是僅是沿著Si(111)排列。Al(100)鋁島與Si(111)矽基板的晶格排列情況，會依據Si(111)任一晶格方向進行成長。在不同熱退火溫度下Al(111)鋁島分別有趨勢偏向Al(√7×√7)R5°, Al(2×2)R19°以及 Al(√7×√7)R10°，三種晶格方向。
並列摘要
In recent years, single-layer and several atomic layers of two-dimensional materials have gradually attracted much attention in the semiconductor industry. In 2004, Hong Liu et al had successfully grown aluminum thin films on Si (111) substrates at low temperatures (145 K). We hope to grow aluminum film at room temperature. In this experiment, We deposit Aluminum on Si (111) substrates with Molecular beam epitaxy(MBE) at RT .And annealing Sample . Finally, we use scanning tunneling microscopy (STM) to find direct information of the film texture, orientation and morphology in great detail. And then, we analyze STM image with software SPIP and python. We change temperature of annealing (230 °C, 350 °C) and Al coverage (0.8 ML, 1.7 ML, and 3.0 ML) and observe their difference. Although we did not get well Aluminum thin film, we grow the overlayer orderly and find the 2D Al island will follow specific direction. We discover Al overlayer which grows Al(√3×√3)R30° ,another one follows with Si (111) primitive vector. Al(100) 2D island which grow follow single of Si(111) substrates primitive translation vector and Al(111) 2D island which grow follow Si(111) substrates Al(√7×√7)R5°, Al(2×2)R19° ,and Al(√7×√7)R10°.