以過濾式陰極電弧沉積系統合成碳氟( a-C:F)薄膜及其鑑定之研究

Characteristics and properties of fluorinated amorphous carbon (a-C:F) films deposited by filtered cathodic vacuum arc plasma system

薛仰志(Yang-Chih Hsueh)

指導教授 ： 施漢章

國立清華大學/工學院/材料科學工程學系/碩士(2007年)

https://doi.org/10.6843/NTHU.2007.00401

摘要

在本實驗中，我們是以CF4作為前驅物，以固態石墨靶﹙碳純度達99.99%﹚作為陰極材料，並使用本實驗室之過濾式陰極電弧電漿沈積系統合成非晶質類鑽碳膜。其中我們藉由改變製程中的負偏壓以及CF4氣體流量來觀察非晶質碳氟薄膜﹙a-C:F films﹚性質上所發生的變化，以分辨出在何種條件之下薄膜擁有最適合應用在所需目的上的特質。本實驗裡利用X光電子能譜﹙XPS﹚來觀察此非晶質碳膜的化學鍵結行為，發現隨著負偏壓的上升，皆會導致薄膜鍵結往低能遷移的特性。另外，還利用拉曼光譜來鑑定薄膜石墨化的程度；利用低掠角的X光繞射得到薄膜的晶體結構；利用掃瞄式電子顯微鏡得到膜厚和薄膜的表面形貌，觀察到當氣體流量30 sccm和負偏壓675 V左右時，薄膜的表面形貌將從純粹的薄膜結構轉變成直徑約為10–20 nm的均勻奈米顆粒，並同時利用原子力顯微鏡﹙AFM﹚來判定薄膜的表面粗糙度變化和進一步的表面形貌，發現隨著通入氣體流量和負偏壓的上升皆會造成薄膜表面粗糙度的提升﹔利用液滴法測量接觸角，觀察在薄膜上的表面自由能變化﹔最後利用奈米檢測系統探討薄膜的機械性質。

關鍵字

DLC ； 碳氟薄膜 ； FCAP

並列摘要

Diamond-like carbon (DLC) films are known for their high mechanical hardness, high wear resistance, low friction coefficients, optical transparency, electrical resistivities, besides, have extensively applications in many areas such as the electronic devices, high precise mechanisms, etc. Even though the incorporation of fluorine into DLC films will reduce their surface energy, don’t change their original excellent properties. The hydrophobic characteristics attach DLC films superior properties can be used in nonstick kitchenware and protective coatings for optical instruments.
The feathers of DLC films are defined by the method of production. The key point of DLC is the fraction of sp3 bonding, and it’s decided by ion energy. Via former reports, we have already know many different production process of causing different ion energy, such as direct dual ion beam deposition(DDIBD), plasma-based ion implantation (PBII), plasma-enhanced chemical vapor deposition (PECVD), filtered cathodic arc plasma system (FCAP) and others.
Filtered cathodic vacuum arc plasma system is a developed technology for depositing amorphous DLC films, It has the advantages of a high deposition rate and low deposition temperature. The cathodic arc can guarantee a good diamond-like film quality by generating highly ionized plasma (30–100%).There is a magnetic filter before the substrate, it can removes the neutrals and macro-particles that are produced by bombarding the carbon target.
This relationships between various bias voltage and CF4 flow rate of the a-C:F films were explored in this research.