FinFET Gate Layout With Variable-Width Fins for Short Defect Prevention
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Solution Overview
Problem
The increasing demand for high-performance semiconductor devices with high integration and operational accuracy poses challenges due to the limitations of planar metal oxide semiconductor FETs, particularly in maintaining high operating speed and accuracy as devices shrink in size, necessitating the development of three-dimensional channel structures.
Innovation Solution
A semiconductor device design featuring fin structures with varying widths and gate lines arranged at specific pitches, along with epitaxial patterns and device isolation patterns, to enhance design freedom and reliability, preventing short defects in source/drain regions by removing width change regions through partial gate line cuts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If planar metal oxide semiconductor FETs are used to achieve simple structure and ease of manufacture, then manufacturing precision is maintained, but device integration density and operational speed deteriorate
Solution Approach 1:
The patent transitions from planar (2D) channel structures to three-dimensional fin structures, extending the channel in the vertical dimension. This allows increased integration density without proportionally increasing planar footprint, while maintaining manufacturability through standard semiconductor processing techniques adapted for fin geometries.
Solution Approach 2:
The device is segmented into multiple fin structures arranged in an array, with each fin acting as an independent channel. This segmentation allows the total channel width to be increased for higher drive current and integration density while keeping individual fin dimensions manageable for fabrication.
2Adaptability or versatility
If fin width is varied to enhance design freedom and functionality, then device versatility improves, but manufacturing precision and uniformity deteriorate
Solution Approach 1:
The patent implements fin structures with different width characteristics in different regions: first fins with uniform width for standard transistor regions, and second fins with varying widths for specialized regions requiring adjusted current drive or threshold voltage. This local differentiation achieves design versatility while maintaining manufacturing precision within each region type.
Solution Approach 2:
Instead of varying fin width continuously across the entire device, the patent applies width variation only to specific fin groups (second fins) where design flexibility is needed, while maintaining uniform width for the majority of fins (first fins). This partial application of width variation balances versatility with manufacturing uniformity.
3Adaptability or versatility
If gate lines are arranged at different pitches to accommodate varying fin widths, then design flexibility improves, but device complexity and fabrication difficulty increase
Solution Approach 1:
The patent employs a unified gate line structure that serves multiple functions: it provides electrical control for both uniform-width first fins and variable-width second fins, and acts as an alignment reference for subsequent processing steps. This universal gate structure simplifies fabrication by maintaining consistent pitch and spacing across the entire device, reducing complexity despite fin width variations.
4Reliability
If width change regions are removed to prevent short defects, then device reliability improves, but manufacturing complexity increases due to partial gate line cuts
Solution Approach 1:
The patent extracts or removes the problematic width change regions from the active device area by implementing partial gate line cuts that eliminate fins in transition zones where width variations could cause short defects. This extraction isolates the reliability issue from the main device structure, preventing shorts while maintaining the beneficial variable-width fins in stable regions.
Solution Approach 2:
The gate line cut pattern is designed in advance to preemptively remove width change regions before they can cause manufacturing or operational problems. By planning the partial cuts during the layout and fabrication process design stage, the patent prevents short defects before they occur, rather than attempting to fix them afterward.
Data Source
AI summary
A semiconductor device is provided, the semiconductor device including; a substrate; a first fin structure extending on the substrate in a first direction, and having a first fin portion having a first width and a second fin portion having a second width; a second fin structure extending on the substrate in the first direction, and having the second width; first gate lines disposed on the first fin portion and the second fin structure, and extending in a second direction; second gate lines disposed on the second fin portion and the second fin structure, and extending in the second direction; a third gate line disposed on the second fin structure, and extending in the second direction between the first and second gate lines; and a device isolation pattern connected to an end portion of the third gate, and extending between the first and second fin portions.