本計畫是我們規劃探討二維材料缺陷物理，為期四年的計畫。我們計畫透過基板表面處理與 內部缺陷清理來調控化學氣相沉積的結核數與成長速度，微調反應氣體比例調控蝕刻與沉積 比率，以及利用電漿解離促進碳源前驅氣體的分解以達到減少依賴表面催化反應的目的。上 述研究可以幫助進一步了解缺陷在二維材料成長的物理機制並對實現二維材料量產的進展做 出貢獻。在二維材料成長完成，我們計畫利用原子力顯微鏡在二維材料上進行掃描探針微影 達到局部結構與化學變化形成奈米缺陷結構、利用離子佈植在二維材料上形成摻雜缺陷或結 構性破壞、利用電漿表面處理在二維材料上形成官能基進行能隙調控、並持續以同步輻射x 光光源研究二維材料缺陷的修復動力行為。在本計畫中我們也計劃建構與精進一些量測技術 以致對所產生的缺陷有更好的物理理解。其中我們將建構一套新的即時量測化學氣相沉積系 統以研究原位即時的缺陷產生與演化動力、添購一台二維壓電顯微平台以改善目前自製二維 拉曼光譜系統的空間解析度、置入一物鏡於原有的原子力顯微鏡系統並與拉曼光譜耦合建置 尖端增強拉曼光譜系統、以及持續改進目前在同步輻射量測掃描光電子能譜的樣品製備與資 料擷取程序。 ;Within the scope of this proposal, we aim to study the physics of defects in two dimensional (2D) materials, with strong emphasis on graphene. To achieve the above goal, novel engineering efforts are needed in hardware and software construction, data acquisition procedure refinement, and data analysis and model building. To realize the above goals, we seek MOST funding support in equipment procurement and operation maintenance. First, defects generation and evolution during growth of 2D materials is going to be studied. Study on the interplay between substrate conditions, ambient control and energy input in the growth process are planned. In term of substrate, nucleation density manipulation by surface treatment will be employed. Ambient control by delicate gas ratio tuning will be used to manipulate the deposition/etch rate in each respective growth step. While for energy input, we will use inductive coupled plasma to enhance the dissociation rate of carbon precursor, thus bypassing the surface catalytic reaction. Second, we plan to generate defects in 2D materials after growth by various methods. Scanning probe lithograhy is used to locally oxidize or create vacancy on the 2D films with controllable defect density. Ion implantation with controllable dose and energy will be used to create doping or vacancy like defects on supported or suspended 2D materials. Plasma treatment will be employed to created functionalization or structural defects. The defect creation processes are technologically important but generally poorly explored issues to date. On the other hand, the reduction or recovery mechanisms are also very intersting scientific issue to be studied. For better characterization, we plan to implement a time resolved direct monitoring system into a CVD system to fully study the defect generation and evolution process during growth. Besides that, a more refined Raman mapping system will be constructed by incorporating a piezo stage into our existing tool. We also plan to implement a light collecting objective into our atomic force microscope system to achieve tip enhanced Raman spectroscopy. Last of all, we will keep improving the sample preparation and data acquisition technique for scanning photolectron microscopy in synchrotron radiation center to achieve better chemical mapping capability.
