A Dual Probes AFM System with Effective Tilting Angles to Achieve High-Precision Scanning

隨著微奈米技術的大幅演進，對於微奈米結構之精確量測已經成為目前一個相當重要之議題。而原子力顯微鏡是一種具有高解析能力的精確量測工具，因此近年來已經被廣泛地運用於微奈米結構之輪廓量測。然而，由於傳統原子力顯微鏡之單一探針傾斜角設計，當量測樣本在邊緣具有大幅度傾斜之特性時，無法避免量測樣本與掃描探針間相對角度之量測誤差，間接造成掃描結果的扭曲與失真。 為了改善上述之量測失真問題，本研究提出一新型雙掃描探針原子力顯微鏡掃描系統，此系統具備高度適應性，它可以隨著各種樣本輪廓特徵分別對兩根掃描探針調整一個適合的探針傾斜角度。此外，本研究也提出一種探針傾角計算之方法，在不同的樣本輪廓特徵下可以有效地計算出所需之探針掃描傾角，在兩根掃描探針個別以所設計之傾角掃描完成後，藉由所開發的掃描結果疊合之演算法，將兩根掃描探針得到之掃描資料有效地合併，以準確地還原樣本原始的輪廓特徵。 最後，本研究將提出之精確掃描方法與局部掃描策略結合，使其所開發之原子力顯微鏡系統具備高速與高精確度的掃描能力。從一系列的實驗結果可以證實此研究所提出的方法效果。With the constant improvement of micro/nano-fabrication techniques, the measurement of feature size of micro/nano-fabricated structures becomes an important issue. Atomic force microscopy (AFM) is a high accuracy measurement instrument that has been widely used in measuring of micro/nano-fabricated structures recently. However, due to the monotonic tilting angle of a single probe in a traditional AFM system, the scanning results of the measured sample with high steep wall features usually exhibit distortion phenomenon at the corner part. To solve this problem, a novel dual probe AFM system is proposed in this thesis. A highly flexible system structure is adopted in this work to create different tilting angle of each probe. With the method developed for the right tilting angle, we can obtain the effective tilting angles under different scanning scenarios. In addition, a useful merging method is also designed in this thesis, which can stitch the scanning results from two different scanning units probes together to produce high-precision overall scanning results. Finally, by combining the proposed scan method with some local scan strategy developed in our lab, we can achieve high-speed precision scan. Experimental results are shown to validate the outstanding capability of the proposed methods by applying in our self-development AFM system