Self-compensating design for focus variation
Self-compensating design for focus variation
复制标题
焦点变化自补偿设计
DOI：
10.1145/1065579.1065677
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
D. Sylvester
中科院分区：
文献类型：
--
作者：
Puneet Gupta;Andrew B. Kahng;Youngmin Kim;D. Sylvester
工艺变化已经成为可预测和高成品率IC设计和制造的瓶颈。芯片中由于散焦引起的线宽变化(/SPL Delta/L)在布局完成后很大程度上是系统性的，即密集的线条通过聚焦“微笑”，而孤立的(ISO)线条则“皱眉”。在这篇文章中，我们提出了一种设计流程，允许显式补偿焦点变化，无论是在单元内(自补偿单元)还是跨关键路径的单元(自补偿设计)。假设每个文库细胞都有iso和密集变体可用，我们就可以实现对焦点变化更稳健的设计。采用自补偿单元库的设计在补偿焦点变化的同时会导致/SPL sim/11-12%的面积损失。与原始单元库相比，混合了密集和ISO单元变体的跨单元优化导致了/SPL sim/6-8%的面积开销，同时满足了大范围焦点变化(从0到0.4/SPL Mu/m)的时序限制。原始单元和ISO单元的组合提供了更好的自补偿设计选项，仅有1%的面积开销。与传统设计方法相比，采用自补偿单元和自补偿设计的电路延迟分布更紧密。
Process variations have become a bottleneck for predictable and high-yielding IC design and fabrication. Linewidth variation (/spl Delta/L) due to defocus in a chip is largely systematic after the layout is completed, i.e., dense lines "smile" through focus while isolated (iso) lines "frown". In this paper, we propose a design flow that allows explicit compensation of focus variation, either within a cell (self-compensated cells) or across cells in a critical path (self-compensated design). Assuming that iso and dense variants are available for each library cell, we achieve designs that are more robust to focus variation. Design with a self-compensated cell library incurs /spl sim/11-12% area penalty while compensating for focus variation. Across-cell optimization with a mix of dense and iso cell variants incurs /spl sim/6-8% area overhead compared to the original cell library, while meeting timing constraints across a large range of focus variation (from 0 to 0.4/spl mu/m). A combination of original and iso cells provides an even better self-compensating design option, with only 1% area overhead. Circuit delay distributions are tighter with self-compensated cells and self-compensated design than with a conventional design methodology.