- 學位論文
以微波電漿束化學氣相沉積系統於石英基材成長之類鑽碳薄膜的電磁性能
Electromagnetic Performance of Diamond Like Carbon Films Grown on Quartz Substrates Using the Microwave Plasma Jet Chemical Vapor Deposition System
摘要
碳元素以不同的型態存在地球上，其中類鑽碳薄膜具有sp2與sp3鍵結，藉由改變類鑽碳中sp2與sp3鍵結比例，可使類鑽碳薄膜同時具有鑽石及石墨之材料特性。實驗中，改變工作壓力及甲烷濃度來沈積不同sp2與sp3鍵結比例之類鑽碳薄膜，使具有優良的電導率性質，以增加電磁屏蔽性能。利用微波電漿束化學氣相沈積(Microwave plasma jet chemical vapor deposition，MPJCVD)系統沈積類鑽碳薄膜於石英基材上，並探討類鑽碳薄膜在不同工作壓力及甲烷濃度參數改變下，其結構性質對電磁屏蔽效應之影響。進而固定工作壓力及甲烷濃度並添加不同氮氣濃度，觀察氮氣添加對電磁屏蔽效應影響。 實驗結果可證實，工作壓力提升至80 torr時，使類鑽碳薄膜表面形貌轉變成脊狀奈米鑽石，降低類鑽碳薄膜中sp3含量至47 %，且提升表面粗糙度至100 nm。類鑽碳之結構變化可提升疏水性至137度，並降低片電阻值至7.11(ohm/squar)，提升類鑽碳薄膜之電磁屏蔽性能至18 dB(吸收及反射係數分別為4 dB、14 dB)。並且當工作壓力為80 torr且氮氣濃度增加0.2 %時，電磁屏蔽性能會降至17 dB，但氮氣濃度的加入可提升類鑽碳薄膜之吸收係數至12.5 dB，並降低反射係數至4.5 dB。
並列摘要
Different forms of carbon widely exist in the Earth and one of them is Diamond like carbon (DLC) film, which is organized by sp2 and sp3 bonds. By changing the ratio of sp2 to sp3 in DLC film, DLC film can simultaneously have the material characteristics of diamond and graphite. In this study, in order to make DLC film have excellent conductivity to increase the performance of electromagnetic shield, working pressure and Methane concentration are changed to depose DLC film, which has different ratios of sp2 to sp3. Microwave plasma jet chemical vapor deposition (MPJCVD) system is used to depose DLC film on the quartz substrate and the influence of the structure properties of DLC film in different working pressures and Methane concentration on electromagnetic shield effectiveness is discussed. In addition, working pressure and Methane concentration are fixed and different Nitrogen concentration is added to observe the influence of the addition of Nitrogen on electromagnetic shield effectiveness. The result of this study verifies that the working pressure, which rises to 80 torr, can make the surface morphology of DLC film turn into ridge-like nanodiamond, decrease sp3 content in DLC film structure to 47 %, and increase the rough degree of DLC film surface to 100nm. The changes of DLC film structure can increase hydrophobicity to 137°, decrease sheet resistance to 7.11 (ohm/squar), and rise electromagnetic shield effectiveness of DLC film to 18 dB (absorption coefficient is 4 dB and reflection coefficient is 14 dB). Moreover, when working pressure is 80 torr and Nitrogen concentration rises to 0.2 %, the performance of electromagnetic shield effectiveness will decrease to 17 dB; however, the addition of Nitrogen concentration can increase absorption coefficient of DLC film to 12.5 dB and decrease reflection coefficient to 4.5 dB.