高精密三維光電顯微鏡之非線性補償研究

Study on Nonlinear Compensation for Enhancing the Vertical Resolution of Three-dimensional (3-D) Electro-Optical Laser Microscope

黃士逢(Shih-Feng Huang)

指導教授 ： 邱銘宏

國立虎尾科技大學/電機資訊學院/光電與材料科技研究所/碩士(2012年)

摘要

本研究基於幾何光學、臨界角法之原理，衍生出一種非掃描非干涉的三維反射式光學顯微鏡，利用物體表面上的高度差所造成的反射光角度改變，再經由平行四邊形稜鏡將此角度改變轉換成靈敏的出射光強度改變。
為考慮稜鏡反射率對高度轉換之非線性誤差造成量測表面高度的誤差而進行補償之研究，可將此非線性誤差減至最低，使得所得之三維影像更接近真實。
此三維反射式光學顯微鏡，其放大倍率可達到兩百五十倍以上，可提供次微米的量測，並擁有奈米級的縱向解析度，可同時量測二維與三維之影像，量測上無論是粗糙之表面抑或是光滑表面上的小缺陷皆能快速被檢測出，量測速度上因為使用CCD擷取影像，如拍照一般，所以可做為大面積快速之即時量測，十分創新有趣。

關鍵字

CCD ； 臨界角 ； 顯微鏡

並列摘要

In this study, we proposes a non-scanning, non-interferometric, three- dimensional (3D) optical microscope based on geometric optics, and critical angle principle. According to the first-order optic approximation, the deflection angle of the reflection light from the test specimen is proportional to its surface height.
In addition, the reflectance of a parallelogram prism is also proportional to the incident angle at the critical angle nearby. We used two charge-coupled devices (CCD) as cameras to record the images at the critical angle nearby and at the angle of total internal reflection, respectively, for making a reflectance profile. The reflectance profile can be transformed into the 3-D surface profile of the test surface.
Because the reflectance curve versus the incident angle is nonlinear, the nonlinear-error compensation is need to do in order to reduce the error and to enhance the measurement accuracy. This is one of the focus in this study.
The reflectance profile, obtained from CCDs, is the ratio of intensity recorded at the critical angle to the intensity recorded at the total internal reflection angle. The 3-D microscope provides a sub-micron measuring range with nanometer resolution in the axial direction and can also be used to measure roughness, film thickness or surface defects in real time.

並列關鍵字

CCD ； critical angle ； microscope ； three-dimensional measurement

參考文獻

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