由於非晶質碳膜製程簡單、沉積溫度低且不需做成尖錐Spindt結構就可以場發射電子，大幅降低製作場發射元件成本，因此被視為極有潛力的場發射材料。但在近期研究報導中指出量測其場發射性質時，需要將電壓快速升降數次以達穩定的場發射電流，稱為conditioning效應，而限制其在場發射器元件上的應用。此外目前研究對於碳膜場發射電子的機構尚未完全釐清，依據Robertson所提之團簇模型，藉由提升非晶質碳膜之導電通路，可進一步改善其場發射特性。
本研究嘗試以微波ECR電漿源耦合R.F.偏壓的方式，將氮原子摻雜於非晶質碳膜中，並以拉曼光譜、高解析電子顯微鏡及ESCA分析微結構，測試場發射性質，探討微波功率、R.F.偏壓及摻雜氮含量對非晶質碳膜成長、微結構與場發射性質之影響。
實驗結果顯示隨著氮摻雜量增加，碳膜中sp2碳鍵結增加且團簇尺寸減小，使其拉曼光譜的G peak往高波數偏移，且ID/IG比值增加。藉由高解析電子顯微鏡觀察，發現碳膜中序化的團簇尺寸隨氮含量增加而扭曲縮小。以原子力顯微鏡觀察鍍膜表面型態，發現鍍膜表面非常平整，沒有表面幾何侷限的存在。經由ESCA分析氮含量並鑑定氮碳鍵結，可確認摻雜之氮原子在非晶質碳膜結構中取代苯環結構內的碳原子(Narom)而造成序化結構扭曲，並成為團簇間的架橋原子(Nbridge)，增加電子傳導路徑，使碳膜之場發射性質隨氮含量增加而改善，起始電壓由14.1 V/μm(氮含量1.0 at%)降低至1.4 V/μm(氮含量4.9 at%)。

Amorphous carbon thin films recently are regarded as a promising candidate for the FED cathode material. The advantage of carbon based thin films is the simplification of the manufacturing process compared to the formation of Spindt tips and the lower deposition temperature. However, it was found, during field emission testing, necessary to ramp the voltage up and down several times in initial stage in order to stabilize I-V curves which is called conditioning effect, which limits its application in field emission. Besides, according to the cluster model as proposed by Robertson, a better emission property can be achieved if path conductivity of amorphous carbon films can be enhanced. Therefore, in this study an attempt is made to incorporate nitrogen into amorphous carbon films. The influences of incorporating nitrogen on the growth characteristics and the improvement of field emission properties are investigated.
Electron cyclotron resonance plasma dual with R.F. bias was used to synthesize nitrogen-containing amorphous carbon films with a CH4+N2 gas mixture. The effects of nitrogen content, microwave power and R.F. bias on the structural and electrical properties of thin films had been determined by Raman spectroscopy, HRTEM, XPS and field emission test.
Experimental results show that the shift of G peak position toward higher wavenumber increases with nitrogen content increasing indicating that the effect of nitrogen addition is to promote the C sp2 bonding. From the Gaussian fitting results of ID/IG value combined with the observation of HRTEM, it could be confirmed that the size of ordering cluster domain decreases with nitrogen content increasing. The binding energy analysis from ESCA spectra of C 1S and N 1S for nitrogenated amorphous carbon films indicates that the N atoms incorporate either by substituting C atoms in the aromatic rings (Narom) or connecting these sp2 microdomains (Nbridge). The emission test results show that the electron emission properties could be improved by reducing electric threshold field from 14.1 V/μm to 1.4 V/μm as nitrogen content increases from 1.0 at% to 4.9 at%. The AFM observation shows that the surface is so smooth that there should exist no geometric field enhancement. Thus the incorporation of nitrogen into amorphous carbon films could introduce the matrix/cluster interface with suitable electronic characteristics for easily conducting electrons, i.e. the path conductivity of amorphous carbon films is enhanced by incorporating nitrogen, and subsequently improves the emission properties.

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