Semiconductor Latchup Control via Well Contact Spacing
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Solution Overview
Problem
The increasing demand for high-density and high-performance semiconductor devices has led to a prevalence of the latchup effect, which creates a low resistance path between voltage supplies, causing circuit failure and potential destruction due to large currents.
Innovation Solution
Varying the spacing, dimensions, and distance between source/drain regions and well contact regions to create different configurations, allowing for the analysis of latchup effects and determining optimal configurations to prevent or control latchup.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If design features are shrunk to increase density, then productivity and chip packaging density are improved, but the latchup effect becomes more prevalent and reliability deteriorates
Solution Approach 1:
The patent applies local quality by making the well contact region larger than the source/drain regions in specific high-risk areas. This localized enlargement of the well contact region creates different structural properties in different parts of the device - larger well contacts where latchup risk is highest, while maintaining smaller overall feature sizes for high density. This resolves the contradiction by protecting reliability through local structural modification without sacrificing overall productivity.
Solution Approach 2:
The patent implements preliminary action by designing the well contact region dimensions and spacing parameters before latchup can occur. By pre-configuring the well contact region to be larger than source/drain regions and positioning it at specific distances, the structure proactively prevents latchup conditions from developing, rather than reacting to latchup problems after they occur. This allows high-density design while maintaining reliability through advance prevention.
2Reliability
If well contact region dimensions are increased to control latchup, then reliability is improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent applies parameter changes by modifying the dimensional parameters of the well contact region relative to source/drain regions. Specifically, it changes the well contact region to have larger length and/or width dimensions compared to the source/drain regions, and positions it at optimized distances. These parameter modifications directly control latchup effects while maintaining a relatively simple structural configuration that is manufacturable with standard semiconductor fabrication processes.
3Reliability
If spacing between source/drain regions and well contact regions is varied to control latchup, then reliability is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent implements preliminary action by pre-establishing the spacing relationships between well contact regions and source/drain regions in the design phase. By determining optimal distances beforehand and incorporating these into the fabrication mask design, the spacing is automatically established during manufacturing without requiring additional precision control steps. This approach improves reliability through proper spacing while avoiding increased manufacturing precision requirements.
Data Source
AI summary
A method includes varying spacing between at least one of a source region or a drain region and a well contact region to create a group of configurations. The method further includes determining an effect of latchup on each configuration.