在線路圖案的定義過程，無論是使用什麼型態的曝光系統，對準量測技術皆為關鍵的製程步驟，在曝光之前能夠準確的將載台進行可以有效減少製程的重工率，進而降低製程成本。本實驗室在先前的研究過程中，發現使用數位微影系統定義的光阻圖案結果與能量規劃演算結果具有一定程度的對準誤差 (Overlay) ，分析後發現基材載台與光學引擎載台偏移為主要誤差因子，因此本文提出基於莫爾條紋 (Moiré Fringe) 的對位量測方法，應用於數位微影系統的基材載台與光學引擎載台對位，根據本文所設計光學對位模組，可量測出兩平面間的相對線性位移及相對旋轉位移，未來可回授此偏移量於數位微影系統進行曝光前的校正補償。本文首先分析莫爾條紋位移量與實際位移量之間的關係，接著設計可應用於數位微影系統的光學對位之光路架構，最後以光柵做為對準符號實際建構對位量測模組，並量測兩組位移範例，並以計算相位差的方式來預測實際位移量。實驗結果顯示此光學架構可偵測0.1µm的最小精度線性位移，且量測誤差控制在±0.03µm之內，以及可偵測0.1°的最小精度角位移，且量測誤差控制在±0.03°之內。

In the definition of circuit patterns, alignment metrology plays a crucial role in the advanced lithography. Align the stage precisely before exposure to minimize rework rates and reduce the production cost. In recent researches, we found that the mismatch results occur between the real resist pattern results and optical simulation produced by the digital lithography system. The error factors come from the misalignment of the substrate and the optical engine stages. This research proposes alignment measurement techniques based on Moiré fringe, where is applicable in the digital lithography system. This designed optical alignment module can detect the linear and angular displacement between the two stages. The author constructs the mathematical formula between Moiré fringe and the actual displacement, and designs the setup of optical alignment used in digital lithography system. The author uses the phase grating as the alignment mark for two cases of alignment modules to predict overlay. The experimental results show that this module can detect a linear overlay of 0.1 µm and the measurement error is controlled within ±0.03µm; angular overlay of 0.1° and the measurement error is controlled within ±0.03°.

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