Adaptive Dummy Pattern Placement for Metal Density Control
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Solution Overview
Problem
As microfabrication technologies advance, achieving uniform metal density across layers in semiconductor devices becomes increasingly difficult, leading to potential distortion in signal timing and increased manufacturing costs due to the need for repeated layout design.
Innovation Solution
A method and computer program that adaptively place dummy patterns of varying widths to ensure metal density is within a desired range, using a layout design tool to place electrically active patterns and dummy patterns, and generate masks for semiconductor device manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If dummy patterns of fixed width are placed to achieve metal density uniformity, then metal density can be controlled, but the ability to adapt to varying design requirements and achieve precise density control is limited
Solution Approach 1:
The patent applies local quality by placing dummy patterns of different widths (first width for first dummy patterns, second width for second dummy patterns) in different regions of the semiconductor chip. This allows the metal density to be locally optimized in different areas, achieving both precise density control and adaptability to varying design requirements across the chip surface.
Solution Approach 2:
The patent changes the width parameter of dummy patterns to control metal density. By using dummy patterns with at least two different widths, the system can adjust the metal density parameter more precisely and adapt to different design requirements, resolving the contradiction between precision control and adaptability.
2Productivity
If metal density is not uniform across layers, then layout design is simpler, but distortion occurs in the stacking process causing signal timing changes and yield reduction
Solution Approach 1:
The patent applies preliminary action by placing dummy patterns during the initial layout design phase to pre-compensate for metal density non-uniformity. This preliminary placement of dummy patterns ensures that metal density is uniform across layers before the stacking process, preventing distortion and signal timing issues while maintaining design efficiency.
Solution Approach 2:
The patent applies preliminary anti-action by intentionally adding dummy patterns that counteract the expected metal density non-uniformity. These dummy patterns create an opposing effect that compensates for the density variations, preventing the harmful distortion effects from occurring during the stacking process.
3Ease of manufacture
If existing dummy pattern forming rules are used for metal fill, then the process is simple, but achieving the desired metal density becomes difficult or impossible
Solution Approach 1:
The patent applies dynamics by making the dummy pattern width variable rather than fixed. The system dynamically selects between first width and second width dummy patterns based on the specific design requirements and metal density targets, maintaining process simplicity while achieving precise density control that static rules cannot provide.
Data Source
AI summary
Disclosed is a computer-readable medium including a program code. The program code, when executed by a processor, causes the processor to place an electrically active pattern having a first width and a first least margin area, on a layer, to place a first dummy pattern having a second width wider than the first width and having a second least margin area, on the layer, and to place a second dummy pattern having a third width and a third least margin area, on the layer, based on whether a ratio of an area of the layer to areas of the electrically active pattern and the first dummy pattern is within a reference range.