Metal-Density-Driven Placement for CMP Variation and Routability

In this paper, we propose the first metal-density driven placement algorithm to reduce CMP variation and achieve higher routability. Based on an analytical placement framework, we use a probabilistic routing model to estimate the wire density during the placement. Then, the metal density and thickness are predicted by a predictive CMP model. The spreading forces are adjusted according to the metal density map to reduce the metal density variation. Experimental results show that our method reduces the topography variation by 12% and the number of dummy fills by 6% and achieves much better routability, compared with wirelengthdriven placement. Categories and Subject Descriptors: B.7.2 [Integrated Circuits]: Design Aids General Terms: Algorithms, Design, Performance

• Type: Journal
• Year: 2008
• Where: TCAD
• Authors: Tung-Chieh Chen, Minsik Cho, David Z. Pan, Yao-Wen Chang
• Keywords: Metal Density, Metal Density Map, Metal Density Variation, TCAD 2008