Guard Ring Structure for IC Noise Isolation and Stress Management
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Solution Overview
Problem
Integrated circuit (IC) devices face yield and performance reductions due to lateral stresses and moisture oxidation, necessitating a guard ring structure for moisture isolation and structural reinforcement.
Innovation Solution
A guard ring structure comprising a semiconductor substrate with a circuit region encircled by two rings, where the rings have opposite dopant types and include doping regions and interconnect elements to form P-N junction diodes, reducing substrate noise coupling and enhancing structural integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high-resolution photolithography and anisotropic plasma etching are used to reduce feature sizes and increase device packing density, then device packing density is improved, but lateral stresses spread along die boundaries and reduce yield and performance
Solution Approach 1:
A guard ring structure comprising a P-type doping region and an N-type interconnect element is formed around the circuit region. The N-type interconnect element acts as an intermediary that blocks lateral stress propagation from die boundaries into the core circuitry, thereby protecting yield and performance while maintaining high device packing density
Solution Approach 2:
The guard ring structure combines two different dopant types (P-type and N-type) to form a composite structure. This composite structure provides both mechanical stress management and electrical isolation functions, resolving the contradiction between high device packing density and reliable circuit operation
2Reliability
If environment moisture is present, then oxidation of ICs in the die occurs, but this oxidation reduces yield and performance thereof
Solution Approach 1:
The guard ring structure with opposite dopant types serves as an intermediary barrier that prevents moisture-induced oxidation from reaching the core IC circuitry. The doped regions create a protective interface that blocks harmful moisture interaction while allowing the ICs to function properly
Solution Approach 2:
The guard ring structure is formed in advance around the circuit region to preemptively block moisture oxidation before it can damage the ICs. This preliminary protective structure prevents oxidation by creating a barrier that stops moisture ingress at the periphery before reaching sensitive circuit elements
3Strength
If a guard ring structure is formed for moisture isolation and structural reinforcement, then structural reinforcement is improved, but device complexity increases
Solution Approach 1:
The guard ring structure merges multiple functions into a single integrated structure: moisture isolation, structural reinforcement, and electrical isolation are all achieved through the same P-type doping region and N-type interconnect element configuration. This merging reduces overall device complexity compared to implementing separate structures for each function
Solution Approach 2:
The guard ring structure is designed as a multi-functional element that simultaneously provides mechanical strength, moisture protection, and electrical isolation. This universal structure eliminates the need for multiple separate components, thereby reducing device complexity while maintaining structural reinforcement
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
The guard ring structure effectively reduces substrate noise transmission and enhances the structural reinforcement of IC devices, improving yield and performance by isolating and suppressing noise across various frequency ranges.
Implementation Method 1
the first and second ring respectively comprises a plurality of separated first doping regions formed in a top portion of the semiconductor substrate, having a second dopant type opposite to the first dopant type
Data Source
AI summary
A guard ring structure having a semiconductor substrate with a circuit region encircled by a first ring and a second ring. At least one of the first and second ring includes: a plurality of separated doping regions formed in various top portions of the semiconductor substrate, providing P-N junction or N-P junction on bottom of the plurality of separated doping regions; and an interconnect element formed over the semiconductor substrate, covering at least portion of the plurality of separated doping regions.