摘要
本研究使用亮場顯微鏡為量測系統，透過應用跨焦調變方式與選取適當的跨焦演算法則，發展出一套可以快速檢測出晶圓中光柵圖案之週期與超過光學繞射極限之次波長級與奈米級線寬的技術。在過去以跨焦技術執行光柵圖案線寬量測時，常需先以其他量測工具確認光柵週期，再進行線寬檢測，而所使用的線寬檢測資料庫也多為以線寬為週期一半處為中心呈現對稱性變化的現象，而本研究以Talbot光學繞射效應為理論基礎，並結合Entropy跨焦演算法將跨焦曲線正規化後，建立一套同步判斷光柵週期與線寬的技術，即由跨焦曲線圖先判定光柵之週期後，再以此週期之資料庫同時進行線寬檢測，在相同週期的光柵試片中，所有線寬變化與跨焦量測值為1對1之比對，可避免過去線寬資料庫比對時產生誤判的可能性，週期與線寬比對時間約數毫秒即可完成，而線寬在±4nm變化時仍可檢測出其變異性，顯示系統有奈米等級之檢測靈敏度。
並列摘要
This study utilizes bright-field microscope as a measurement system for developing a technique based on the through-focus method. It allows a rapid examination of the grating pitch of wafers and the line-width of nano and below optical diffraction limit sub-wavelength wires via selected through-focus algorithms. Previously, when examining grating pattern line-width through the use of through-focus method, often the grating pitch must first be confirmed by using other analysis tools, separate from line-width analysis. In addition, the line-width database also presents a symmetrical phenomenon at half the grating pitch. This study focuses on the Talbot effect as foundation, coupled with Entropy through-focus algorithm that normalizes the through-focus focus metric (TFFM) profile, further allowing the establishment of a technique that allows simultaneous analysis of the grating pitch and line-width. The TFFM profile first determines the grating pitch, which is then used simultaneously to conduct line-width analysis. The correspondence between a specific line-width and the related measured through-focus focus metric is one to one against the grating specimen of the same pitch, avoiding the possibility of misjudgment due to comparisons using past data. The time difference between grating and line-width comparison is shortened to within milliseconds, even allowing detection of anomaly when line-width is at ±4nm. This shows the system has nano-scale sensitivity.