考量極紫外光閃焰及化學機械研磨之電路繞線

Simultaneous EUV Flare- and CMP-Aware Routing

楊嘉倫(Chia-Lun Yang)

指導教授 ： 郭斯彥

國立臺灣大學/電機資訊學院/電子工程學研究所/碩士(2016年)

https://doi.org/10.6342/NTU201600693

摘要

極紫外光微影是最有前途的下一代微影技術之一，但此微影技術遭受閃焰（散射光）效果的影響，進而導致關鍵尺寸的失真和均勻性的損失。此外，化學機械研磨消除氧化矽、金屬和多晶矽的表面差異，在現今的積體電路製造過程中是不可或缺的一個重要過程。這些製造性的問題與佈局密度分布有著高度相關，然而，這兩種技術間最佳化的佈局密度分布存在著相對的差異性，針對紫外光閃焰，佈局密度分布趨勢為晶片中央區域密度較高的凸型曲面可獲得較佳的閃焰最佳化結果，而針對化學機械研磨，保持密度分布的均勻性可獲得較佳的研磨成果。為了要控制佈局密度分布，電路繞線是一個關鍵的階段。藉由電路繞線，其結果將顯著影響金屬密度分布。在這篇論文中，我們提出了一個電路繞線的演算法可以同時考慮極紫外光閃焰、化學機械研磨。其中，我們在繞線最一開始的階段，根據之前電路擺置的結果來計算散射光影響分布圖，從而選擇適當的Steiner Tree，根據這個Steiner Tree來獲得良好的繞線結果。為了在每次繞線之後要更新散射光分布圖的時候，我們提出一個有效的方式來迅速的更新分布圖並減少其失真。實驗結果顯示，我們提出的電路繞線演算法可以有效地和高效地同時最佳化極紫外光的閃焰影響、化學機械研磨。

關鍵字

實體設計 ； 極紫外光微影 ； 閃焰 ； 化學機械研磨 ； 可製造性 ； 繞線

並列摘要

Extreme Ultraviolet Lithography (EUVL) is one of the most promising lithography technologies for next generation, but EUVL suffers from the flare effects (i.e., scattered light) which cause critical dimension (CD) distortion and damage CD uniformity. Moreover, Chemical Mechanical Polishing (CMP) is an important process which planarization silicon oxide, metal, and polysilicon surfaces in modern IC manufacturing. Both of the manufacturability issues are highly related to layout pattern distribution. However, there is a trade-off between the two techniques because the desirable pattern distributions for EUV flare and CMP optimization are different. To minimize EUV flare effects, a concave density distribution is preferred, where the center of a chip has the higher density than periphery regions. On the other hand, CMP optimization tends to keep the density distribution uniform. In addition to control layout pattern distribution, routing is a critical stage in VLSI design flow because the wire density would significantly affect metal distribution. In this thesis, we propose the first work of EUV flare- and CMP-aware routing that considers the two manufacturability issues. Besides, we use the flare map which is calculated by previous placement result. According to this flare map to choose appropriate Steiner tree. In the other hand, every time we finish one net routing, we need to update flare map. We propose an efficient way to quickly update flare map and reduce distortion. The experimental results show that our proposed algorithms can effectively and efficiently achieve the routing solutions with optimized EUV flare effects, the CMP cost.

並列關鍵字

Physical design ； EUV ； Flare ； CMP ； Manufacturability ； Routing

參考文獻

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