溫度與離子束對高分子縱深分析之影響

Effect of Specimen Temperature on C60+-Ar+ Co-Sputtering of Polymers

蔡孟宏(Meng-Hung Tsai)

指導教授 ： 薛景中

國立臺灣大學/工學院/材料科學與工程學研究所/碩士(2012年)

https://doi.org/10.6342/NTU.2012.03239

摘要

聚甲基丙烯酸甲酯 (PMMA)是日常生活中大量被利用之高分子，並且許多學者提出關於利用不同離子束濺射PMMA之濺射機構。在此，本實驗採用Wagner 於2004年提出之斷鍊機構，並以此為依據做更深入的研究。
此外，利用C60離子單獨濺射PMMA已被證實是可以獲得大量且穩定的特徵破片產率，但在界面產生之碳沉積一直是個無法避免的問題，然而，根據本實驗室於2008年所提出的研究顯示，利用共濺射技術可有效的降低界面產生的碳沉積問題，藉此增加可分析深度。此外，為了同時獲得飛濺出的特徵破片與表面化學結構之關係，本實驗採用將X光光電子能譜儀(XPS)與動態二次離子質譜儀(Dynamic-SIMS)裝置於同一主腔體中，藉以同時收集相關資訊。
在本實驗中，比較單原子離子源(Ar+)，多原子離子源(C60+)與共濺射技術濺射PMMA之特徵破片與表面化學結構之關係，藉以推測不同離子源濺射所產生的濺射機構，並改變不同溫度，觀察溫度、入射離子源與濺射機構之關係。在最後，量取濺射達界面時的表面形貌，說明溫度、表面形貌生成與濺射機構之關係。
綜合以上討論，本實驗發現，以0.2 kV 300 nA Ar+在-120 °C 下和C60+ 10 kV 10 nA共濺射為最佳共濺射條件。

關鍵字

C60+-Ar+共濺射 ； 縱深分佈分析 ； 表面分析 ； 動態二次離子質譜術 ； X光光電子能譜 ； 聚甲基丙烯酸甲酯

並列摘要

It is known that owing to high sputtering yield, cluster ions like C60+ produce more high-mass secondary ions and yield less damaged in the remaining surface than atomic ion sputtering. However, in some polymer, damage still accumulates with C60+ sputtering, so that subsequently acquired chemical information during depth profile can be different from its initial state. Beside of using different type of primary ion and mixed ion co-sputtering of different fluence, the effect of specimen temperature to the depth profile of organic materials is examined in this work. The ion beam induced change in the chemical structure of polymethylmethacrylate (PMMA) at different temperatures was examined by X-ray Photoelectron Spectroscopy (XPS) and Dynamic-Secondary Ion Mass Spectrometry (D-SIMS). At lower temperature (-120 °C), because the energy of primary was dissipated more quickly than that at room temperature, less damage to the chemical structure and higher secondary ion intensities are observed. Similar to that observed with SF5+ ion sputtering, the sputtering rate increases with increasing temperature. This behavior is attributed to that the cluster ion beam tends to scissor the polymer chains and delay the cross-linking, the higher mobility of molecules at higher temperature promoted the sputtering materials. On the other hand, it is found that the sputter rate decreased with increasing temperature when low-energy Ar+ is used concurrently. This opposite behavior is attributed to that the Ar+ induced radicals and the high mobility at higher temperature allows cross-linking hence the sputtering rate decreased with increasing temperature. Furthermore, in co-sputtering, it was expected that higher sputter energy would yield higher sputter rate. However, because of the interaction between ion beams leads to the breakage the C60 ion, the use of high energy Ar+ yields lower sputter rate.

並列關鍵字

XPS ； Dynamic-SIMS ； PMMA ； temperature ； C60+-Ar+ co-sputtering ； surface analysis ； depth profile.

參考文獻

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