超奈米微晶鑽石薄膜用於場發射元件及引導神經再生之研究

Studies of Ultra-nanocrystalline Diamond Films on Field Emission Devices and Nerve Regeneration

陳盈潔(Ying-Chieh Chen)

指導教授 ： 戴念華 ； 林諭男

國立清華大學/工學院/材料科學工程學系/博士(2009年)

摘要

本研究發展出一種嶄新的製程方式「低壓高溫偏壓輔助法」，在氫氣/甲烷電漿下，直接成長超奈米微晶鑽石薄膜。此製程所成長之薄膜具有的特性與現有氬氣電漿下所成長的薄膜性質十分相似，具有鑽石晶粒 (3-5 nm)，但卻具有更平坦的表面 (~6 nm均方根)與更快的成長速率(~1 µm/小時)。進一步藉由X光同步輻射、原子力顯微鏡和穿透性電子顯微鏡探討其成核成長的機制。
為了促進鑽石的場發射特性，我們發展出三種方式來達成：第一，氮原子在高溫下被參雜到超奈米微晶鑽石薄膜，藉由提升基板的溫度。第二，將氮參雜的超奈米微晶鑽石薄膜沉積在奈米矽線上，奈米矽線的場發射特性藉由沉積氮參雜的超奈米微晶鑽石薄膜可以大大提升。第三，高溫成長的超奈米微晶鑽石薄膜利用離子佈植的方式將氮離子佈植在鑽石膜的表面。其相關的可能機制也將被探討。
鑽石本身已被證實具備生物相容性，因此我們進一步探討超奈米微晶鑽石在生物方面應用的可行性。主要研究著重於超奈米微晶鑽石跟神經幹細胞的相互作用，進而提升鑽石在生物材料方面的應用特性。利用普通的培養皿作為對照組來分別探討經過氫氣或氧氣電漿改質超奈米微晶鑽石對神經幹細胞的成長、延展與分化的影響。

關鍵字

超奈米微晶鑽石薄膜

並列摘要

The fundamental process underlies the synthesis of ultra-nanocrystalline diamond (UNCD) films, using a modified low-pressure, heat-assisted bias-enhanced nucleation and growth (BEN-BEG) technique, involving H2/CH4 chemistries. This growth process yields UNCD films similar to those produced by the Ar-rich/CH4 chemistries, with pure diamond nanograins (3-5 nm), but smoother surface (~6 nm root-mean-square) and higher growth rate (~1 µm/hr). X-Ray synchrotron analysis, atomic force microscopy, and transmission electron microscopy studies on the BEN-BEG UNCD films provided information critical to understand the nucleation and growth mechanism and growth conditions-nanostructure-properties relationships.
For the purpose of improving the electron field emission properties (EFE) of the UNCD films, we developed three different approaches: Firstly, nitrogen species were doped into UNCD films by microwave plasma chemical vapor deposition (MPCVD) process at high substrate temperature. Secondly, nitrogen-doped UNCD was conformal coated on silicon nanowires by a modified ultra-sonication process. The EFE properties of silicon nanowires were pronouncedly improved due to UNCD coating. Lastly, nitrogen ions with varied energies were implanted into UNCD films grown by microwave plasma chemical vapor deposition process at high substrate temperature 800°C. The EFE properties of the films were significantly improved. The feasible mechanisms will be discussed.
The interaction of UNCD with neural stem cells (NSCs) has been studied and its surface modification in order to improve its function as a biomaterial has been investigated. Hydrogen- and oxygen-terminated UNCD films were compared with standard grade polystyrene in terms of their impact on the growth, expansion, and differentiation of NSCs.

並列關鍵字

UNCD

參考文獻

2. Wang, W.L., Liao, K.J., Fang, L., Esteve, J. & Polo, M.C. Analysis of diamond nucleation on molybdenum by biased hot filament chemical vapor deposition. Diamond Relat Mater 10, 383-387 (2001).

3. Sekaric, L. et al. Nanomechanical resonant structures in nanocrystalline diamond. Applied Physics Letters 81, 4455-4457 (2002).

4. Yugo S, Kanai T, Kimura T, Muto T Generation of diamond nuclei by electric-field in plasma chemical vapor-deposition. Applied Physics Letters 58, 1036-1038 (1991).

5. Wolter SD, Stoner BR, Glass JT, Ellis PJ, Buhaenko DS, Jenkins CE, Southworth P Textured growth of diamond on siliconn via insitu carburization and bias-enhanced nucleation. Applied Physics Letters 62, 1215-1217 (1993).

6. Lee YC, Lin SJ, Lin CY, Yip MC, Fang WL, LinIN Pre-nucleation techniques for enhancing nucleation density and adhesion of low temperature deposited ultra-nanocrystalline diamond. Diamond Relat Mater 15, 2046-2050 (2006).