散射式掃描近場光學顯微鏡一次十奈米級光學檢測

Scattering-Type Scanning Near-Field Optical Microscopy-Optical Characterization in sub-10 nm Scale

朱仁佑(Jen-You Chu) ； 汪天仁(Tien-Jen Wang) ； 張祐嘉(You-Chia Chang) ； 葉吉田(Jyi-Tian Yeh) ； 王俊凱(Juen-Kai Wang)

《科儀新知》 163期 (2008/04) Pp. 35-45

https://doi.org/10.29662/IT.200804.0005

摘要

傳統光學顯微鏡的解析度受限於光學繞射因素而無法達到奈米尺度。傳統孔洞式掃描近場光學顯微鏡雖然可克服此限制，但是其解析度限於五十奈米以上，且其光訊號隨孔洞縮小而急速下降，無法進行高解析度的奈米檢測。筆者介紹一套自我發展擁有小於十奈米光學解析度的散射式掃描近場光學顯微鏡。它利用原子力顯微鏡的探針針尖當散射源，來增強在針尖前端與樣品間的侷限電場。藉由外差干涉、探針調制及光路設計等技術，可同時於多波長下記錄地貌、近場光場強度及相位影像。這項技術能夠用以探測奈米材料的光學特性及因奈米結構所產生的電磁場變化，可以期待對於未來奈米科技的發展將能夠作出重大貢獻。

並列摘要

The resolution of classical optical microscopy is limited by optical diffraction and cannot reach nanometer scale. Although aperture-type scanning near-field microscopy can overcome this limitation, its spatial resolution is limited to 50 nm and its optical throughput decreases drastically with the decrease in the aperture size, obstructing its application in nanometer-scaled characterization. We have developed an interferometric scattering-type scanning near-field optical microscope which owns a sub-10 num resolution. This microscope takes advantage of the nanometer-scaled tip apex of an atomic force microscope to enhance the localized field between the tip apex and sample. Taking advantage of heterodyne, modulation and optical design technique, it has the ability to record topography, near-field optical and phase artifact-free images at multiple laser wavelengths simultaneously. This technique is highly promising for nanoscaled optical characterization and for mapping out the local field distribution around nanostructures. It is expected that this instrument can make significant contribution to the development of nanoscience and nanotechnology.