使用空間載頻相位偏移技術量測薄膜的表面輪廓及厚度

Thickness and Surface Profile Measurement of Thin Film by Using Spatial Carrier Phase Shifting Technique

沈家裕(Chia-yu Shen)

指導教授 ： 李正中

國立中央大學/理學院/光電科學研究所/碩士(2012年)

摘要

本研究主要是以建立一套抗震動的相移式光學薄膜量測系統，可以量測二維的表面輪廓(Surface Profile)、薄膜光學常數和厚度，為一個非破壞性的量測系統。
本量測系統只要是為了取代偏極陣列像素遮罩法(Micro- Polarizer-Array-Pixelated Mask)的相移式光學量測系統，本實驗架設系統，具有相同的量測功能且使用的光學元件也較少。有別以往PZT相移式量測方法，可以避免環境震動的影響且同時具有橢偏儀折射率和厚度的量測功能，又可以量測表面輪廓。
本研究主要是使用空間載頻相移技術在系統中引進一個傾斜量來作為四步相位的量測方法，因此可以得到表面輪廓的資訊。利用多波長的量測方法，使用基因演算法擬合出薄膜的折射率及厚度，結果與橢偏儀比較，有很好的一致性。

關鍵字

薄膜 ； 厚度 ； 相移 ； 表面輪廓

並列摘要

Our research is used to build a vibration-insensitive phase-shifting interferometer to measure optical constants of thin film. Two-dimensional surface profile, optical constants and thickness of thin film can be measured by this interferometry, which is a nondestructive measurement.
Our interferometer can replace phase-shifting interferometer, which has a micro-polarizer-array-pixelated mask placed in front of CCD. Both interferometers have the same function. But a few of optical device is used in our measurement system. Our system has the function in measuring refractive index and thickness of thin film like ellipsometer and also the surface profile additionally, and it can avoid the fluctuation of environment, different from PZT phase-shifting interferometry.
The system is based on spatial carrier phase shifting technique, a tilt is introduced to make up the four-step phase-shifting information, and therefore the surface profile can be obtained. The multi-wavelength measurement can help to solve the refractive index and thickness of thin film by fitting the reflective phase and reflectance with gene algorithm and our interferometer has almost the same quality as ellipsometer in measurement.

並列關鍵字

thin film ； thickness ； surface profile ； phase shift

參考文獻

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