液體在旋轉塗佈過程中，由於離心力之作用，使不穩定手指狀會在連續液膜波前處產生。本實驗針對旋轉塗佈過程中，中心塗佈與環形塗佈不穩定手指狀流的產生，進行探討及研究，希望藉由環形旋塗研究來控制螺旋旋塗之不穩定手指數；實驗中利用晶圓不同的距離、不同機台轉速，不同的初始狀態及計算方式，進行塗佈半徑與面積相關聯之比較，藉此觀察旋轉塗佈過程中，距離、轉速以及初始塗佈的狀態，對流體連續薄膜波前發展的現象，並與相對應的中心塗佈比較，藉以研究兩者塗佈不穩定手指狀流相關的影響，以達到理想的塗佈臨界半徑與塗膜液體減量的效果。實驗結果發現在高黏度矽油低邦得數下，中心塗佈可以獲得比環形塗佈好的塗佈半徑，且中心旋塗初始半徑越大可以獲得較佳的塗佈面積。而環形塗佈不管距離遠近，都較中心塗佈易受初始狀態的影響。在兩者相對應關係的探討中，中心塗佈與環形塗佈兩者有形狀上的差異，此種差異會造成比較方式上的問題，所以利用不同的計算方式進行比較，發現外徑法因只單純計算臨界半徑的長度，故能減低初始條件對於臨界半徑的影響，因此此種計算方式較其它種能消除外在的因素，更能獲得較佳的比較。 In spin coating, the instability fingers would arise at the front of continuous liquid film wave due to the centrifuge. This experiment was studied the generation of fingering instability and the maximum attainable radius during the Center Injection and the Ring Injection. Hope to control the instability fingers of Spiral Injection. Different wafer distance, different rotational speed, different initial state, and different computing ways were used to compare the coating radius and area and to observe if the instability fingers would arise at the front of continuous liquid film wave that the photoresist decrement and the ideal critical radius of coating could be achieved. The results showed that in high viscosity silicon oil and low Bond number, the Center Injection could get better radius than Ring Injection, and the lager initial radius could get better coating area. Furthermore, Ring Injection was easier affected by the initial state than Center Injection. Compare to the result of two relations, Center Injection and Ring Injection are different in the structure, and this kind of difference would cause some problems in the comparative way. If we compare to the different calculation ways, it could find that the decrease of external diameter could lower affect by initial state than other factors.
