吳志毅Wu, Chih-I臺灣大學:光電工程學研究所徐誠志Hsu, Chen-ChihChen-ChihHsu2010-07-012018-07-052010-07-012018-07-052008U0001-0808200816450300http://ntur.lib.ntu.edu.tw//handle/246246/188369利用掃描穿隧顯微鏡研究低溫成長於矽Si(100)-2×1表面的鉛薄膜。有三種鉛島會形成: 六角形表面平坦的鉛(111)島嶼，長條型表面平坦的鉛(100)島嶼和長條型三維的鉛島嶼。對於表面平坦的鉛(111)島嶼，島的厚度局限在4~10個原子層之間。觀察其數量分布，以6層高的島嶼最多。這種成長行為起源於量子尺寸效應。利用掃描穿遂能譜不同厚度的島嶼測量到量子井態。利用量子力學中無限位能井模型可以解釋這個結果。此外，表面平坦的鉛(100)島嶼和三維的鉛島嶼每跨過一個臺階方向會轉90°。這現象意味著鉛(100)島嶼和三維的鉛島嶼會受到矽Si(100)-2×1表面重購的影響The growth of Pb film on the Si(100)-2?1 surface has been investigated at low temperature using scanning tunneling microscopy. Three kinds of Pb islands are formed: hexagonal flat-top Pb(111) islands, rectangular flat-top Pb(100) islands, and rectangular 3D Pb islands. For flat-top Pb(111) islands, the thickness of islands is confined within the range of 4 to 10 atomic layers. Among these islands, those with heights of six layers are most abundant. This growth behavior is a result of the quantum size effect. Quantum well states are detected by scanning tunneling spectroscopy on the Pb islands of varying thickness. A simple model based on the infinite potential well can explain our results. Besides, flat-top Pb(100) islands and 3D islands rotate by 90? from one terrace to the next. This phenomenon implies that the structures of Pb(100) and 3D islands are influenced by the Si(100)-2?1 surface.Acknowledgements Ibstract IIIable of Contents Vist of Figures VIIhapter 1. Introduction 1hapter 2. Experimental principles 4.1 Principles of scanning tunneling microscopy (STM) 4.2 Local density of state (LDOS) 6.3 STM operating modes 8a) Constant current mode 9b) Constant height mode 10c) Current image tunneling spectroscopy (CITS) 11.4 Quantum Size Effect (QSE) and Quantum Well States (QWS) 12a) Quantum size effect (QSE) 12b) Quantum well states (QWS) 13.5 Three traditional growth modes 15.6 Si(100)- 2?1 reconstruction 16hapter 3. Experimental Instruments and Procedures 19 3.1 Experimental Setup 19 3.2 Ultra-high-vacuum (UHV) System 20 (a) Dry rotary Pump 20b) Turbo molecular pump 20c) Ion pump 21d) Titanium sublimation pump (TSP) 22.3 Evaporator system 23.4 Tip preparation 25.5 Experimental procedures 26 (a) Nearly defect-free Si(100)-2?1 reconstruction 26 (b) Pb deposition 27hapter 4. Results and Discussion 28.1 Growth mode 28.2 Growth characteristics of 2-D Pb(111) islands on Si(100)- 2?1 surfaces 33.3 Temperature effect 35.4 I-V spectra of Pb(111) islands 38.5 Comparison with Pb/Si(111) system 43.6 Conclusion 45eference 461887260 bytesapplication/pdfen-US掃描穿隧顯微術量子尺寸效應掃描穿隧能譜術鉛島量子井態Scanning Tunneling MicroscopyQuantum Size EffectScanning Tunneling SpectroscopyPb islandQuantum Well Statesthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/188369/1/ntu-97-R95941041-1.pdf