Patterned Ground Shield for Semiconductor Inductor Parasitic Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing patterned ground shield structures in semiconductor devices introduce parasitic effects that reduce the quality factor Q of inductors, despite their intention to decrease substrate loss.
Innovation Solution
A patterned ground shield structure with multiple conductive rings and interconnection lines is designed, featuring sub conductive rings with uneven distribution and a ground ring, which reduces parasitic resistances and capacitances by distributing shielding effects uniformly and matching fabrication processes with CMOS transistors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a patterned ground shield is formed between inductors and the substrate, then substrate loss is reduced, but the quality factor Q of inductors is reduced due to parasitic effects
Solution Approach 1:
The ground shield is divided into multiple patterned regions (e.g., interdigitated fingers or geometric patterns) rather than a continuous structure. This segmentation reduces the parasitic capacitance between the ground shield and the inductor while maintaining effective substrate loss reduction through the distributed grounding points.
Solution Approach 2:
The ground shield structure is optimized with varying patterns in different regions - areas closer to the inductor use sparser patterns to minimize parasitic effects, while areas farther away use denser patterns to maximize substrate loss reduction. This local optimization balances both requirements.
2Loss of energy
If a patterned ground shield is formed to decrease substrate loss, then energy loss is reduced, but parasitic resistances and capacitances increase
Solution Approach 1:
The ground shield is segmented into multiple isolated conductive regions rather than a continuous structure. This reduces the total parasitic capacitance between the ground shield and the inductor, as the capacitive coupling is distributed across multiple smaller regions rather than one large continuous area.
Solution Approach 2:
The ground shield pattern extends into the planar dimension with specific geometric arrangements (such as interdigitated fingers with optimized spacing and width). By carefully controlling the dimensional parameters of the pattern, the parasitic capacitance is reduced while maintaining effective grounding functionality.
3Loss of energy
If a patterned ground shield is formed to reduce substrate loss, then energy efficiency is improved, but device complexity increases
Solution Approach 1:
The patterned ground shield structure serves multiple functions simultaneously: it provides substrate loss reduction, acts as a parasitic capacitance reduction mechanism, and can be integrated with existing CMOS fabrication processes. This multi-functionality justifies the increased structural complexity by delivering multiple benefits from a single structure.
Solution Approach 2:
The ground shield pattern parameters (such as finger width, spacing, number of fingers, and overall geometry) are optimized to achieve the desired balance between substrate loss reduction and parasitic effect minimization. By carefully adjusting these parameters, the structure achieves improved performance without excessive complexity.
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 design enhances the quality factor Q of inductors by minimizing parasitic effects and ensuring process compatibility, thereby improving inductor performance and reducing substrate loss.
Implementation Method 1
By forming the patterned ground shield, the majority of electric field lines generated by the inductors may be terminated at the patterned ground shield and unable to enter into the substrate
Implementation Method 2
A patterned ground shield structure with multiple conductive rings and interconnection lines is designed, featuring sub conductive rings with uneven distribution and a ground ring, which reduces parasitic resistances and capacitances by distributing shielding effects uniformly
Data Source
AI summary
A patterned ground shield structure is provided. The patterned ground shield structure includes a substrate having a dielectric layer. The patterned ground shield structure also includes a plurality of conductive rings having a plurality of sub conductive rings in the dielectric layer. Further, the patterned ground shield structure includes an interconnection line connecting with all of the sub conductive rings in the dielectric layer. Further, the patterned ground shield structure also includes a ground ring connecting with the interconnection line.