電漿處理對於奈米碳管/鑽石針尖陣列複合之場發射性質研究

Field emission characteristics of plasma treated carbon nanotubes on diamond tip arrays

賴學良(Lai, Hsueh Liang)

指導教授 ： 蔡宏營

國立清華大學/工學院/動力機械工程學系/碩士(2016年)

摘要

摘要
本研究目的結合電漿蝕刻奈米碳管以及與鑽石薄膜合成複合材料，製作出有一低起始電場與高電流穩定度之優異場發射冷陰極。
研究方法是以鑽石針尖結構來作為奈米碳管與矽基板之間的緩衝層，減少場發射過程中產生之焦耳熱以達到提升奈米碳管電流穩定度之目的；並以不同電漿對成長於鑽石結構上之奈米碳管來進行改質，使碳管結構產生改變，達到降低起始電場之目的。以掃描式電子顯微鏡來觀測電漿對奈米碳管形貌之影響，並以拉曼光譜檢測其結構之變化並且測量其場發射效應。
本研究成功以一新穎製程製作出矽針尖陣列，此製程包含微影與矽等向蝕刻兩步驟，為一簡單且低成本之製程。而之後在矽針尖陣列上依序成長鑽石與奈米碳管，再以電漿處理奈米碳管，形成一新穎場發射陰極端。
本研究所製作之新穎場發射陰極端結合了奈米碳管、電漿處理與鑽石針尖陣列的優點，擁有2.84 V/μm低起始電場，電場到達5.5 V/μm時有0.59 mA/cm2的電流密度，場增益因子為1701，且在15小時內之電流穩定度優於原始奈米碳管與成長於鑽石針尖陣列的奈米碳管。

關鍵字

場發射 ； 奈米碳管 ； 鑽石針尖陣列 ； 電漿處理

並列摘要

Abstract
The purpose of this study is to produce a plasma treated carbon nanotubes (CNTs) composite diamond tip arrays with low turn-on field and steady emission current density. It can be a high performance field emission cathode.
CNTs (for current emission) and diamond (for heat spreading) composite presents good FE properties. The diamond film conducts away the Joule heat, which is generated between CNTs and Si substrate during field emission. The plasma changes the morphology and structure of CNTs and improves the field emission properties. The structural and morphology of treated CNTs are examined by Raman spectroscopy and scanning electron microscopy (SEM), respectively. The field emission effect of treated CNTs are examined by the field emission meter.
Micro Si tip arrays is fabricated by using lithography and XeF2 etching. This novel method is low-cost and simple.
In this study, a novel FE cathode has been fabricated, which combines the advantage of diamond tip arrays, CNTs, and plasma treatment. The cathode presents good FE properties: the turn on voltage is 2.84 V/µm, the current density at 5.5 V/µm is 0.59 mA/cm2, and the field enhancement factor is 1701. The current stability of novel FE cathode is better than as grown CNTs/CNTs on diamond tip arrays.

並列關鍵字

field emission ； carbon nanotubes ； diamond tip arrays ； plasma treatment

參考文獻

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