Paper
23 March 2020 A comprehensive standard cell library qualification to prevent lithographic challenges
Author Affiliations +
Abstract
Standard cells are the most critical and reusable elements to build up the whole chip, therefore foundry has to fully qualify the standard cell libraries to ensure their high quality when releasing to the customers for the chip design. To prevent pattern dependent lithographic difficulty in manufacturing is one target of standard cell qualification and becomes mandatory especially in advanced nodes due to tighter design rules and smaller design size. To identify a lithographic problematic standard cell, we have to take its surroundings within the optical diameter range into consideration because lithographic effects are intrinsically context-dependent. One critical step is to imitate standard cells placements in real designs and consider some important factors like VIA location as it impacts the mask shape directly. When the placement is completed, lithographic simulation is performed by LFD (Litho Friendly Design) to highlight risky locations. Every standard cell has to occur enough number of times to make sure the statistics of possibility of being a problem is reliable. The final statistics will instruct engineers on how to handle the problematic standard cells, either standard cell layouts have to be optimized or building a pattern database to prevent the abutments of particular standard cell combinations.
© (2020) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Xinyi Hu, Qijian Wan, Zhengfang Liu, Zhixi Chen, and Chunshan Du "A comprehensive standard cell library qualification to prevent lithographic challenges", Proc. SPIE 11328, Design-Process-Technology Co-optimization for Manufacturability XIV, 113281C (23 March 2020); https://doi.org/10.1117/12.2551677
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KEYWORDS
Lithography

Standards development

Databases

Photomasks

Statistical analysis

Computer simulations

Metals

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