Estimation Method and Experimental Verification of the Least Cutting Passes for Fabrication of a Nanochannel Trapezium Groove on Single-Crystal Silicon with Changed Downward Force at a Fixed Cutting Depth

預定深度之單晶矽奈米流道梯型凹槽固定下壓深度及改變下壓力之加工到最少切削道次估算方法及實驗驗證

林榮慶(Zone-Ching Lin) ； 馬士閎(Shih-Hung Ma) ； 陳致榮(Zhi-Rong Chen)

《中國機械工程學刊》 42卷5期 (2021/10) Pp. 439-449

摘要

Employing the concept of specific down force energy (SDFE), the paper establishes a method to estimate the least cutting passes for optimal step-by-step approximation to objective convergence function of the expected depth of nanochannel trapezium groove. This method is a two cutting passes offset fabrication method. For this method, a fixed downward force is set at the 1st cutting pass on each cutting layer is set to use. At the 2nd cutting pass, downward force is changed to achieve the same cutting depth as the one at the first cutting pass. Through simulated change of offset amount, the protruding height on the bottom of groove is smaller than the set convergence value. Then, regulating the downward force repeatedly can make the protruding height on botton of groove meet the range of convergence value being below 0.54nm as set by the paper. When a real AFM machine changes the downward force, additional time and efforts have to be spent on changing the downward force. But this paper, for acquisition of the least fabrication lead time during actual application, applies SDFE theoretical model to further estimate the least cutting passes for reaching the expected depth of nanochannel trapezium groove. This method not only can estimate the least cutting passes, but also can make the number of changes of downward force become the least. Finally, the paper even conducts experiments for verification, proving that the above method can really make the fabrication lead time become the least.

關鍵字

atomic force microscope (AFM) ； silicon expected depth ； nanochannel ； least cutting passes

並列摘要

本文利用比下壓能觀念，建立最佳化之逐步逼近到預定之奈米流道梯形凹槽深度之目標收斂函數的最少切削道次之估算方法。其方法為兩切削道次偏移循環加工方法，此方法在每一切削層第一切削道次皆設定一固定下壓力，第二切削道次則改變下壓力取得與第一切削道次之相同切削深度，而經由模擬改變偏移量使凸起高度小於設定之收斂值後再反覆調整下壓力，使得凸起高度滿足本文中所設定之收斂值0.54nm範圍內；實際AFM機台在改變下壓力時，需額外耗費工時來改變下壓力，而本文為了在實際應用上取得最少加工前置時間，則應用比下壓能理論模式進一步估算出可達到預定奈米流道梯形凹槽深度之最少切削道次估算方法，在估算出最少切削道次之外，也使得變換下壓力次數達到最少，本文最後還進行了實驗來驗證，證實了確實可使加工前置時間為最少。