Hierarchical dummy fill for process uniformity

Chen, Yu; Kahng, A.B.; Robins, G.; Zelikovsky, A.

doi:10.1109/aspdac.2001.913294

Cited by 4 publications

(6 citation statements)

References 7 publications

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“…A standard practice in the density calculation is to consider only windows from a fix dissection [5,7,8,9,10,11,12,13,14,17,18,20]. In this approach, a layout is partitioned into M R x N R nonoverlapping RxR windows.…”

Section: Fix-dissection Approach Limitationmentioning

confidence: 99%

Is your layout density verification exact?

Xiang

Chao

Puri

et al. 2007

Proceedings of the 2007 International Symposium on Physical Design

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As the device shapes keep shrinking, the designs are more sensitive to manufacturing processes. In order to improve performance predictability and yield, mask layout uniformity/evenness is highly desired, and it is usually measured by the feature density with defined feasible range in manufacture process design rules. To address the density control problem, one fundamental problem is how to calculate density accurately and efficiently. In this paper, we propose a fast exact algorithm to identify the maximum density for a given layout. Compared with the existing exact algorithms, our algorithm reduces the running time from days/hours to a few minutes/seconds. And it is even faster than the existing approximate algorithms in literature.

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Section: Fix-dissection Approach Limitationmentioning

confidence: 99%

Is your layout density verification exact?

Xiang

Chao

Puri

et al. 2007

Proceedings of the 2007 International Symposium on Physical Design

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“…2 Several models have been proposed in [8], including the model of [10], where the interlevel dielectric thickness z at location…”

Section: Density Models For Oxide Cmpmentioning

confidence: 99%

“…Due to its efficiency and accuracy, these were used for both flat [3,4] and hierarchical [2] layout density control; and Iterated Greedy (IGreedy) and Iterated Monte-Carlo (IMC) methods, which improve the solution quality by iterating the insertions and deletions of dummy fill features with respect to the density variation ( [3]). …”

Section: Introductionmentioning

confidence: 99%

Closing the smoothness and uniformity gap in area fill synthesis

Chen

Kahng

Robins

et al. 2002

Proceedings of the 2002 International Symposium on Physical Design

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Control of variability in the back end of the line, and hence in interconnect performance as well, has become extremely difficult with the introduction of new materials such as copper and low-k dielectrics. Uniformity of chemical-mechanical planarization (CMP) requires the addition of area fill geometries into the layout, in order to smoothen the variation of feature densities across the die. Our work addresses the following smoothness gap in the recent literature on area fill synthesis. (1) The very first paper on the filling problem (Kahng et al., ISPD98 [7]) noted that there is potentially a large difference between the optimum window densities in fixed dissections vs. when all possible windows in the layout are considered.(2) Despite this observation, all filling methods since 1998 minimize and evaluate density variation only with respect to a fixed dissection. This paper gives the first evaluation of existing filling algorithms with respect to "gridless" ("floating-window") mode, according to both the effective and spatial density models. Our experiments indicate surprising advantages of Monte-Carlo and greedy strategies over "optimal" linear programming (LP) based methods. Second, we suggest new, more relevant methods of measuring a local uniformity based on Lipschitz conditions, and empirically demonstrate that Monte-Carlo methods are inherently better than LP with respect to the new criteria. Finally, we propose new LPbased filling methods that are directly driven by the new criteria, and show that these methods indeed help close the "smoothness gap".

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“…Design rule checking and parasitic extraction on flat data with dummy features is almost impossible, because the dummy features are not in the original design hierarchy. A recent study of hierarchical dummy feature placement by Chen et al [4] has found that there is substantial trade-off between solution quality in terms of planarity achieved and the amount of original design hierarchy the inserted dummy features can preserve.…”

Section: Model-based Tilingmentioning

confidence: 99%

Reticle enhancement technology

Grobman

Thompson

Wang

et al. 2001

Proceedings of the 38th Conference on Design Automation - DAC '01

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In this paper, we review phase shift lithography, rule vs. model based methods for OPC and model-based tiling, and discuss their implications for layout and verification. We will discuss novel approaches, using polarizing films on reticles, which change the game for phase-shift coloring, and could lead to a new direction in c:PSM constraints on physical design. We emphasize the need to do tiling that is model-driven and uses optimization techniques to achieve planarity for better manufacturing tolerance in the subwavelength dimensions era. Electromagnetic solver results will be presented which estimate the effect of tiling on circuit timing.

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Hierarchical dummy fill for process uniformity

Cited by 4 publications

References 7 publications

Is your layout density verification exact?

Is your layout density verification exact?

Closing the smoothness and uniformity gap in area fill synthesis

Reticle enhancement technology

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