考量三重曝光微影技術及平衡光罩密度的非點格式細部繞線方法

Abstract

對小於14 奈米的製程節點，三重曝光微影技術(triple patterning lithography)將一層佈局分配到三個光罩可以增加節距與增進解析度。在繞線階段考慮三重曝光微影技術可以增加佈局分割的彈性，而且將佈局平均分割到不同光罩上，可以降低邊緣位置誤差。在本論文中，在考量三重曝光微影技術的非點格式細部繞線方法中同時考慮平衡光罩密度的問題。交換偽顏色及考量密度縫合(stitch)建立用來平衡光罩密度。實驗結果顯示除了考慮整體光罩密度，額外考慮區域光罩密度與縫合數量的取捨。

For the sub-14nm technology node, triple patterning lithography (TPL) is adopted, which decomposes a single layer into three masks to increase pitch and enhance the resolution. In routing stage, considering TPL can improve the flexibility of layout decomposition. Moreover, layouts with balanced density can reduce edge placement error(EPE)[2]. This work considers the mask density balancing based on triple-patterning lithography aware detailed router[6] to improve the printability. Swapping pseudo colors and density aware stitch generation are proposed to balance mask density. The result shows that there is the trade-off between stitch counts and additionally considering the local density constraint besides the global density constraint.