具奈米級圖案之表面粗糙度對接觸角之影響

The Roughness Effect of the Surface with a Grating Structure on the Contact Angle

梁孟堯(Mon-Yun Liang) ； 關旻宗(Min-Tzong Kuan) ； 陳立仁(Li-Jen Chen)

《界面科學會誌》 29卷1期 (2007/03) Pp. 35-42

https://doi.org/10.30020/JCCIS.200703.0004

摘要

為了檢驗Wenzel equation和Cassie equation，本實驗利用微影製程蝕刻製備一系列不同線寬（100μm-0.2μm）的矽晶母片，藉由量測前進接觸角與上述兩個方程式計算得到的理論接觸角數據去做比較。當液滴三相線平行於表面直條紋圖形時的接觸角（145°±4.7）比Cassie equation的理論值（128°±3.6）要大，這可能是因為條紋凸起部份的表面粗糙度（Ra=2~7nm）大於理想的表面粗糙度（Ra=0.1nm）所造成。而當三相線垂直於直條紋圖形時的接觸角（125°±10.5）也比Wenzelequation的理論值 （114°±2.1）要大，除了表面粗糙度的效應外，線張力效應可能也是造成接觸角實驗值都比理論計算值來得大的原因之一。

關鍵字

前進接觸角 ； 粗糙度 ； 三相線 ； 線張力

並列摘要

The lithography technique is applied to etch a series of silicon wafers with a grating structure of different widths (100μm-0.2μm). The advancing contact angle of water on this grating surface is performed and compared to the theoretical values predicted by the Wenzel equation and Cassie equation. While the three-phase contact line of the water droplet is parallel and normal to the stripe, the advancing contact angles are larger than that obtained by Cassie equation and Wenzel equation, respectively. It is believed that this inconsistence is due to the roughness of the grating surface dramatically increased during the etching process. In addition, the line tension may be the other reason to cause the experimental contact angle values larger than the theoretically predicted ones.

並列關鍵字

advancing contact angle ； surface roughness ； three-phase contact line ； line tension