Semiconductor Gate Isolation Layout for Variable Gate Cut Trenches
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Solution Overview
Problem
Existing technologies face challenges in forming gate cut trenches in non-planar transistor devices, particularly when dealing with dummy fins of varying widths, which can lead to issues such as incomplete removal of residual dummy gate structures and failure to successfully cut the metal gate layers.
Innovation Solution
The method involves forming dummy fins of varying widths and selectively forming gate cut trenches that are either in proportion or out of proportion to the wider dummy fin, allowing for concurrent formation of gate cut trenches with different dimensions, thus addressing the issues faced by existing technologies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If gate cut trenches are formed using conventional methods, then the process is simple, but incomplete removal of residual dummy gate structures occurs and metal gate layers fail to be successfully cut
Solution Approach 1:
The patent applies local quality by forming gate cut trenches with different widths based on the specific dummy fin width in different regions. Instead of using a uniform trench width, the method selectively adjusts trench dimensions to match local dummy fin characteristics, ensuring complete removal of dummy gate structures while maintaining process feasibility.
Solution Approach 2:
The patent implements dynamics by making the gate cut trench width variable rather than fixed. The trench width is dynamically adjusted according to the dummy fin width, allowing the process to adapt to different regions of the semiconductor device and achieve complete dummy gate structure removal without increasing overall process complexity.
2Reliability
If dummy fins of varying widths are formed, then electrical coupling of metal gate layers to active fins is improved, but gate cut trench formation becomes more difficult
Solution Approach 1:
The patent resolves this contradiction by applying local quality - forming gate cut trenches with widths specifically matched to the dummy fin widths in each region. This local customization ensures reliable electrical coupling of metal gate layers to active fins while keeping the manufacturing process manageable through systematic region-by-region processing.
Solution Approach 2:
The patent uses segmentation by dividing the semiconductor device into multiple regions based on dummy fin width characteristics. Each region receives appropriately sized gate cut trenches, breaking down the complex task of handling varying widths into manageable segments that can be processed systematically.
3Manufacturing precision
If gate cut trenches are formed to match wider dummy fins, then complete removal is achieved, but trenches may be too large for narrower dummy fins
Solution Approach 1:
The patent applies local quality by matching gate cut trench width to the specific dummy fin width in each region. This ensures complete removal of dummy gate structures from wider fins while avoiding excessive material removal from narrower fins, optimizing both removal completeness and material efficiency.
Solution Approach 2:
The patent avoids excessive action by using partially sized gate cut trenches that are precisely matched to dummy fin dimensions. Instead of using a universally large trench that would guarantee complete removal but waste material, the method uses appropriately sized trenches for each region, eliminating the need for excessive material removal.
Data Source
AI summary
A semiconductor device includes a first transistor, a second transistor, a third transistor, and a fourth transistor. The first and second transistors operate under a lower gate voltage than the third and fourth transistors. The first transistor has a first active gate structure and the second transistor has a second active gate structure. The first and second active gate structures are separated by a first gate isolation structure along a first direction. The third transistor has a third active gate structure and the fourth transistor has a fourth active gate structure. The third and fourth active gate structures are separated by a second gate isolation structure along the first direction. The variation of a first distance between respective sidewalls of the first gate isolation structure is equal to the variation of a second distance between respective sidewalls of the second gate isolation structure along the first direction.