石墨烯是由碳原子所組成的二維平面系統，它的電阻率極低，電子遷移速率快，使石墨烯成為半導體工業取代矽晶圓的最佳材料之一。石墨烯為一零能隙的材料為取代閘極最需克服之問題，必須將石墨烯的能隙打開(gap opening)。產生能隙的方法之一為部分地氧化石墨烯。所以局部地氧化石墨烯對於未來的半導體發展更為重要。本實驗利用掃描探顯微術來局部氧化石墨稀並觀察石墨稀氧化的機制，我們發現氧化產生的結構有部分來自於石墨稀底下矽基板氧化矽的貢獻，利用改變矽基板上氧化層的厚度我們也釐清了氧化石墨稀和氧化矽的比例，也更進一步的了解氧化石墨稀和氧化矽產生的先後次序。經由以上實驗的啟發，我們試著改變矽基板的參雜來改變基板表面的功函數，石墨稀的功函數會隨著底下矽基板的功函數改變而導致不同的氧化行為，經由了解參雜對氧化石墨稀的影響，我們發展出經由氧化石墨稀微調能階的方法。Graphene is a two dimensional system consists of carbon atom. It has low resistance and high electron mobility, and is considered as one of the potential materials to replace silico in semiconductor industry. One of the problem to be overcome in using graphene as a gate in semiconductor devices is the property of gapless energy spectrum. Several ways of gap opening are considered. One way to open the gap is partial oxidation of graphene. Therefore local oxidation of graphene is a key issue for further application in semiconductor. We use atomic force microscopy (AFM) with local anodic oxidation (LAO) to oxidize and observe the mechanism of LAO on graphene. We find that the oxidation height is contributed from underneath silicon oxide protrusion and surface graphene oxide (GO). By varying the buffer oxide layer thickness, we clarify the formation order of GO and silicon oxide. Inspired from above experiments, a concept of using doping difference in template for controlling the LAO is presented. This method may give us a way to fine tune the band gap of graphene.
