質子照射下石墨烯的電子結構之研究

The Electronic Structure of epitaxial graphene/SiC by proton-irradiation

吳祥寧(Shaing-Ning Wu)

指導教授 ： 林敏聰

國立臺灣大學/理學院/物理研究所/碩士(2011年)

https://doi.org/10.6342/NTU.2011.10519

摘要

摘要
石墨烯 (Graphene)是單層的石墨擁有六角蜂窩結構與碳組成的二維平面物質，於科學應用和下一代電子元件上是具有潛力的材料。這歸功於其特殊的能帶結構、電子傳輸、磁性行為和化學穩定性。此外，質子束刻寫 (Proton beam writing)是具有三維製造、奈米解析度、精確刻寫深度的技術。因此，石墨烯電子結構在質子照射下的影響在未來的應用上會是重要的議題。我們的研究中，石墨烯生成於碳化矽 (SiC)表面，利用2.1 MeV的高能質子束以不同劑量參數照射石墨烯。此外，也照射沒有石墨烯覆蓋的碳化矽系統做為對照組。量測上，我們借由具有空間解析度與能量解析度的掃描式光電子顯微術(Scanning PhotoElectron Microscopy-SPEM)在未照射區、照射區以及邊界上量測X光光電子能譜 (XPS)。我們發現，相較於未照射區，石墨烯的sp 2鍵結無明顯變化，但對於底層的碳化矽鍵結有明顯減少。此外，我們發現在碳化矽系統中，邊界上能譜的特徵峰位置有明顯的改變，而在石墨烯/碳化矽系統中只有些微的變化。我們宣稱，石墨烯的電子結構受到質子束照射是較少影響，然而卻對底層的碳化矽有者顯著的改變。這結果對於電子結構的調控具有深度選擇性，將提供一項優點於電子元件的製造與電子結構的調控。

關鍵字

石墨稀 ； 碳化矽 ； 質子束刻寫 ； 掃描式電子顯微術 ； X光光電子能譜

並列摘要

Graphene, a single-layer graphite with a honeycomb structure and two dimensional carbon-based material is served as a promising candidate for next generation devices and scientific application. It’s due to the unique properties about band structure, electronic transport, magnetism and chemical stability.
In this thesis, we utilize proton beam writing technique with SiC by growing the few layers graphene on SiC substrate (graphene/SiC). By employing the proton beam writing technique, we would do the 3-D fabrication with advantages such as nanometer resolution, specific penetration depth and modifying the electric transport properties. In experiment, we used 2.1 MeV protons to irradiate the graphene/SiC structure with different dosage, and irradiated the area without graphene (SiC system) to be a reference area. We employed scanning photoelectron microscopy (SPEM) with spatial and energy resolution to characterize the electronic structures of pristine, boundary and irradiated area. We found that the electronic structure of graphene wasn’t verified but, within the SiC layer, its electronic properties were largely changed. In addition, the electronic structure of SiC system is largely binding energy shift in the boundary as compared with graphene/SiC. We claim that the graphene layer would be more stable than the SiC substrate under proton-irradiation. This study demonstrates that proton-writing technique provides a good depth selectivity to modify the target layer (SiC) of the graphene/SiC structure. It is applicable for the fabrication of electronic device by using proton beam writing.

並列關鍵字

Graphene ； SiC ； Proton beam writing ； SPEM ； XPS

參考文獻

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