Hybrid Fin Cut Process for Uniform Fin Profiles
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Solution Overview
Problem
Conventional fin field effect transistor (FinFET) fabrication processes, such as double patterning lithography, result in varying fin profiles due to loading issues, leading to misalignment and tapering of fins in different density regions, especially when fin spacing increases, causing manufacturing complexities.
Innovation Solution
A hybrid fin cut process with improved fin profiles is introduced, utilizing dummy fin structures in regions with wide fin cut spaces to ensure uniform loading and prevent tapering, achieved through a novel patterning process that includes forming hardmask structures, patterning active and dummy fin structures, and creating shallow trench isolation regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional double patterning lithography is used to form fins, then fin structures can be created, but fin profiles become non-uniform with tapering in different density regions
Solution Approach 1:
The patent segments the fin formation process into multiple regions (first region, second region, third region) with different fin densities, and applies different patterning strategies to each region. Dummy fin structures are added to the third region to match the loading conditions of the first region, ensuring uniform fin profiles across all regions while managing process complexity through regional differentiation.
2Manufacturing precision
If fin spacing is increased to reduce density, then more fin cut spaces are created, but tapering becomes more noticeable on isolated fin sides
Solution Approach 1:
The patent applies preliminary action by forming dummy fin structures in the third region before the actual fin formation process. These dummy structures pre-establish the loading conditions needed to prevent tapering, allowing the fin etch process to proceed uniformly across regions with different spacing requirements without causing profile deviations.
3Manufacturing precision
If dummy fin structures are added to achieve uniform loading, then fin profile uniformity improves, but manufacturing process complexity increases
Solution Approach 1:
The patent applies local quality by adding dummy fin structures only in the third region where wide fin cut spaces cause loading issues, while leaving the first and second regions unchanged. This localized approach achieves uniform fin profiles where needed without unnecessarily complicating the entire manufacturing process, balancing precision requirements with manufacturing simplicity.
Data Source
AI summary
The present disclosure relates to semiconductor structures and, more particularly, to a hybrid fin cut with improved fin profiles and methods of manufacture. The structure includes: a plurality of fin structures in a first region of a first density of fin structures; a plurality of fin structures in a second region of a second density of fin structures; and a plurality of fin structures in a third region of a third density of fin structures. The first density, second density and third density of fin structures are different densities of fin structures, and the plurality of fin structures in the first region, the second region and the third region have a substantially uniform profile.