Multi-Finger ESD Structure With High-Resistivity Guard Ring
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Solution Overview
Problem
Existing electrostatic discharge (ESD) devices exhibit non-uniform triggering and weak ESD protection robustness, particularly in multi-finger configurations, with inefficient use of silicon area.
Innovation Solution
Incorporating a high substrate resistivity band in the guard-ring surrounding the ESD devices, achieved by modifying the well mask layer layout or increasing the depth of shallow trench isolation structures, to ensure uniform current distribution and reduce the footprint by minimizing or omitting silicide block regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional multi-finger ESD device structure is used, then the device can provide ESD protection, but it exhibits non-uniform triggering and weak ESD protection robustness
Solution Approach 1:
The patent introduces a high resistivity band in the substrate surrounding the active regions, creating a non-uniform substrate resistivity distribution. This local modification of substrate properties ensures uniform current distribution across all fingers during ESD events, preventing hot-spot formation and achieving uniform triggering while improving ESD protection robustness
Solution Approach 2:
The patent modifies the substrate resistivity parameter by introducing a high resistivity band with resistivity significantly higher than the surrounding substrate. This parameter change in the substrate structure controls current flow distribution, ensuring uniform triggering across multi-finger devices and improving overall ESD protection performance
2Productivity
If the silicon area is reduced to improve integration density, then more devices can be integrated, but the ESD device footprint efficiency decreases
Solution Approach 1:
The patent removes or minimizes silicide block regions that are typically required in conventional ESD devices. By extracting this non-essential component, the active silicon area is maximized, allowing better utilization of the available footprint and improving integration density without compromising ESD protection functionality
3Manufacturing precision
If uniform current distribution is achieved through high substrate resistivity band, then hot-spots are prevented and triggering is uniform, but the device footprint increases
Solution Approach 1:
The high resistivity band is introduced only in specific regions surrounding the active ESD structure, rather than uniformly across the entire substrate. This localized modification achieves uniform current distribution and prevents hot-spots while minimizing the additional footprint required
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach results in uniform triggering and improved ESD performance by preventing hot-spots and reducing the footprint of ESD devices, compared to conventional structures, with enhanced current density and temperature uniformity across the array.
Implementation Method 1
the outer segment comprises an electrical resistivity higher than the second dopant type
Data Source
AI summary
The present disclosure relates to semiconductor structures and, more particularly, to electrostatic discharge devices and methods of manufacture. The structure includes: a plurality of regions of a first dopant type; insulator material separating each region of the plurality of regions of the first dopant type; and a substrate contacting the plurality of regions of the first dopant type, the substrate comprising a base region of a second dopant type different than the first dopant type and an outer segment surrounding the plurality of regions of the first dopant type, the outer segment comprises an electrical resistivity higher than the second dopant type.