Continuous-Well Tap Cell Structure for Compact Latch-Up Prevention
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Solution Overview
Problem
As integrated circuits become smaller and transistors are packed closer together, latch-up issues arise due to the need for appropriate spacing of tap cells, leading to increased circuit size.
Innovation Solution
The integration of a tap cell structure with continuous active regions and wells, eliminating breaks and enhancing compressive strain through SiGe, reduces the physical size while maintaining driving current capability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If tap cells are placed with appropriate distances to prevent latch-up, then reliability is improved, but the overall circuit size increases
Solution Approach 1:
The patent combines the tap cell structure with the standard cell structure by making the active region continuous between them, eliminating the need for separate tap cell spacing while maintaining latch-up prevention functionality. This merging reduces the overall circuit area occupied by tap cells.
Solution Approach 2:
The continuous active region serves multiple functions: it provides the tap cell functionality for latch-up prevention and simultaneously acts as the active region for the standard cell. This multi-functionality eliminates the need for additional dedicated tap cell structures, reducing circuit size.
2Manufacturing precision
If continuous active regions are used to eliminate breaks, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The patent merges the tap cell and standard cell structures so that the active region is continuous between them. This eliminates breaks in the active region, improving manufacturing precision by reducing alignment requirements between separate structures.
Solution Approach 2:
The continuous active region creates a homogeneous structure between the tap cell and standard cell, eliminating discontinuities and varying material properties that would complicate manufacturing. This uniformity simplifies the fabrication process despite the integrated design.
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 minimizes latch-up occurrences and reduces overall circuit size by up to 0.6% while maintaining or improving driving current capability compared to other methods.
Implementation Method 1
enhancing compressive strain through SiGe
Data Source
AI summary
Provided is a tap cell including a substrate, a first well, a second well, a first doped region, and the second doped region. The substrate has a first region and a second region. The first well has a first dopant type and includes a first portion disposed in the first region and a second portion extending into the second region. The second well has a second dopant type and includes a third portion disposed in the second region and a fourth portion extending into the first region. The first doped region having the first dopant type is disposed in the second portion of the first well and the third portion of the second well along the second region. The second doped region having the second dopant type is disposed in the first portion of the first well and the fourth portion of the second well along the first region.