FinFET Fin Geometry With Rounded Spacer Corners for Dense Scaling
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Solution Overview
Problem
Current semiconductor FinFET technologies face challenges in scaling down transistor density due to difficulties in controlling fin body width and shape, leading to increased pitch and reduced planar area, which fails to meet the demands of Moore's Law for higher transistor density and lower cost per transistor.
Innovation Solution
A new semiconductor transistor structure and manufacturing method that includes a semiconductor substrate with a fin structure having a rounded corner under a spacer, a step-like transition between the fin body and base, and independent conductive regions, allowing for precise control of fin width and shape, thereby reducing the transistor area and preventing fin collapse.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the fin body width is reduced to increase transistor density, then the pitch can be reduced, but the fin structure becomes unstable and prone to collapse
Solution Approach 1:
The fin structure incorporates a rounded corner at the base region instead of a sharp corner, creating a curved transition zone that distributes stress more evenly and prevents structural collapse during scaling to higher transistor densities
Solution Approach 2:
The fin structure has non-uniform width along its height, with a wider base region providing structural support and a narrower top region for optimal channel control, creating different local properties to simultaneously ensure stability and high density
2Manufacturing precision
If the fin body width is precisely controlled, then manufacturing precision improves, but the shape consistency becomes difficult to maintain
Solution Approach 1:
The fin structure is divided into distinct segments with different width characteristics - a wider base segment for stability and a controlled top segment for precision, allowing each segment to be optimized independently while maintaining overall shape consistency
Solution Approach 2:
The rounded corner geometry provides a smooth transition between segments that is easier to manufacture consistently than sharp corners, maintaining shape uniformity across multiple fins while enabling precise width control
3Quantity of substance
If the pitch is reduced to increase transistor density, then the planar area decreases, but the fin body width variation increases
Solution Approach 1:
The fin structure implements local width optimization with a controlled top width for channel region and wider base for support, allowing precise fin body width in the critical channel area while maintaining structural integrity at reduced pitch
4Reliability
If the STI depth and width are optimized, then device performance improves, but the fin shape consistency becomes harder to maintain
Solution Approach 1:
The rounded corner geometry at the fin base provides a stress-distributing curved transition that maintains shape consistency even when STI dimensions are optimized for performance, as the curved geometry is more tolerant to dimensional variations than sharp corners
Data Source
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AI summary
A semiconductor transistor includes a semiconductor substrate with an original surface, an active region, a shallow trench isolation region, a shallow trench isolation region, a first conductive region and a second conductive region located within the active region, and a spacer. The active region is formed based on the semiconductor substrate and the active region has a fin structure. The shallow trench isolation region surrounds the active region and a gate structure of the semiconductor transistor crosses over the fin structure. The spacer contacts to a sidewall of the gate structure and on the fin structure. A width of the fin structure under the spacer is wider than that of the fin structure under the gate structure, the fin structure has a lateral profile along a direction substantially parallel to the original surface, and the lateral profile of the fin structure includes a rounded corner under the spacer.