Standard Cell Layout Via Contact Density Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing techniques fail to effectively reduce variations in via contact density in semiconductor integrated circuits, leading to manufacturing defects and low fabrication yield, particularly in standard cell layouts with impurity diffusion regions and gate areas.
Innovation Solution
The strategic placement of dummy via contacts in sparse regions such as impurity diffusion regions, dummy impurity diffusion regions, and shared impurity diffusion regions connected to transistors, without necessitating additional layout area, allows for the reduction of via contact density variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If dummy via contacts are disposed on shallow trench isolation regions to eliminate non-uniformity in via contact distribution, then via contact density uniformity is improved, but layout area increases and manufacturing defects are not sufficiently reduced in standard cell layouts
Solution Approach 1:
The invention applies local quality by selectively placing dummy via contacts only in specific sparse regions (impurity diffusion regions, dummy impurity diffusion regions, and shared impurity diffusion regions) rather than uniformly across the entire layout. This targeted approach improves via contact density uniformity in critical areas without unnecessarily increasing the overall layout area, as dummy via contacts are strategically positioned only where density variations occur.
Solution Approach 2:
The invention utilizes existing structural regions (impurity diffusion regions, dummy impurity diffusion regions, and shared impurity diffusion regions) for dual purposes: their original transistor formation function and additionally as locations for dummy via contacts. This multi-functionality allows the dummy via contacts to be integrated into the standard cell layout without requiring additional dedicated space, thereby improving via contact density uniformity without proportionally increasing layout area.
2Manufacturing precision
If uniform spacing between gates is maintained to reduce gate size variations, then transistor performance uniformity is improved, but insufficient space remains for dummy via contacts in standard cell layouts
Solution Approach 1:
The invention maintains uniform gate spacing throughout the standard cell layout to ensure transistor performance uniformity, while simultaneously applying local quality by placing dummy via contacts only in specific sparse regions (impurity diffusion regions and related areas) where space is naturally available. This selective placement strategy preserves the uniform gate structure while providing adaptability for dummy via contacts in appropriate locations without requiring non-uniform gate spacing.
Solution Approach 2:
The invention utilizes existing impurity diffusion regions and related structures for dual purposes: their original transistor formation function and additionally as locations for dummy via contacts. This multi-functionality provides the necessary layout flexibility for placing dummy via contacts while maintaining the uniform gate spacing required for transistor performance uniformity, as the dummy via contacts are positioned in regions that naturally exist within the uniform gate structure.
3Productivity
If standard cell layouts are optimized for area reduction by disposing impurity diffusion regions and gate regions, then layout efficiency is improved, but via contact density variations increase
Solution Approach 1:
The invention optimizes standard cell layouts for area reduction by efficiently arranging impurity diffusion regions and gate regions, while simultaneously applying local quality by identifying and targeting specific sparse regions (impurity diffusion regions, dummy impurity diffusion regions, and shared impurity diffusion regions) for dummy via contact placement. This selective approach improves via contact density uniformity in the sparse areas created by the efficient layout, without compromising the overall layout efficiency.
Solution Approach 2:
The invention uses existing impurity diffusion regions and related structures for dual purposes: their original transistor formation function and additionally as locations for dummy via contacts. This multi-functionality allows the layout to maintain high efficiency with compact arrangements while simultaneously addressing via contact density uniformity, as the dummy via contacts are integrated into the efficient layout structure without requiring additional space beyond what is already allocated for impurity diffusion regions.
Data Source
AI summary
In a layout structure of a standard cell including off transistors 126, 127 unnecessary for logic operation of a circuit, dummy via contacts 116, 117 are disposed on impurity diffusion regions 103, 106 of the off transistors 126, 127, respectively. Dummy metal interconnects 122, 123 are connected to the dummy via contacts 116, 117, respectively. Thus, variations in the density of via contacts, which are one of causes lowering the production yield of semiconductor integrated circuits, is reduced, improving manufacturing defects of the via contacts.