利用表面增強拉曼散射光譜檢測原子層沉積技術製備之極薄膜

Applications of Surface Enhanced Raman Spectroscopy on Nanoscale Ultrathin Films Prepared by Atomic Layer Deposition

粘立暐(LI-WEI NIEN)

指導教授 ： 陳敏璋

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.2012.10407

摘要

極薄膜在奈米材料和固態元件扮演重要的角色。本論文使用表面增強拉曼散射效應來檢測奈米尺度的非晶相薄膜，藉由激發奈米尺寸金屬結構的侷域化表面電漿共振，以增強待測物拉曼光譜的強度。
　　本研究利用低溫原子層沉積技術成長非晶相的氧化鈦奈米薄膜，由變角度橢圓儀測量可知，氧化鈦介電常數隨著氧化鈦的堆疊和結構排序增加而上升。在不同厚度之氧化鈦薄膜上，我們利用熱蒸鍍法製作金奈米結構層使之產生侷域化表面電漿共振和產生表面增強拉曼散射效應，進而檢測到厚度僅為2奈米氧化鈦之拉曼光譜。
　　延續上述之研究，利用原子層沉積技術成長一層不同厚度之氧化鋁在金奈米結構顆粒和待測物（氧化鈦/玻璃、砷化鎵）之間，觀察表面增強拉曼散射效應對於金屬奈米結構與待測物間距離的變化，發現增加1奈米氧化鋁至待測物與金奈米結構之間會增強待測物之拉曼強度，但增加氧化鋁厚度從1奈米到20奈米會降低待測物之拉曼強度。

關鍵字

表面增強拉曼散射效應 ； 侷域化表面電漿共振 ； 原子層沉積技術 ； 氧化鈦

並列摘要

The ultrathin films play an important role in the nanoscale materials and solid state devices. The discovery of surface enhanced Raman scattering (SERS) facilitates the detection of the nanoscale amorphous thin films because of large enhancement factor by exciting the localized surface plasmon resonance (LSPR).
The probed ultrathin TiO2 films deposited by low temperature atomic layer deposition (ALD) are amorphous. The dielectric constants of TiO2 films, measured by variable-angle spectroscopic ellipsometry, increase with the films thickness because of the increase in atomic layer stacking and the ordering of structure. Thermal evaporation was used to fabricate the nanostructured Au layer upon the TiO2 films with different thickness for enabling LSPR and SERS sensing. Structure characterization of the amorphous nanoscale TiO2 film as thin as ~2 nm was achieved by the SERS technique.
Extending the above research, an Al2O3 layer with different thickness was inserted between the probed materials (TiO2/glass and GaAs) and the Au nanostructure to study the distance dependence of SERS. It was been observed that inserting a 1nm Al2O3 layer between the probed materials and Au nanostructure enhances the Raman intensity. However, increasing the thickness of the Al2O3 layer from 1nm to 20nm decreases the Raman intensity.

並列關鍵字

surface enhanced Raman scattering (SERS) ； localized surface plasmon resonance (LSPR) ； atomic layer deposition (ALD) ； titanium oxide (TiO2)

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