MIM Capacitor Guard Ring Layout for Leakage Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional semiconductor devices with MIM capacitors experience leakage current due to potential differences between MIM capacitors and guard rings, and have a large footprint, hindering size reduction.
Innovation Solution
The semiconductor device arranges MIM capacitors with a guard ring outside the outermost capacitor, eliminating interposed guard rings between adjacent capacitors and reducing the overall footprint, thereby minimizing leakage current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a guard ring is arranged to surround the periphery of individual upper electrodes, then the MIM capacitors are protected from interference, but leakage current occurs due to potential difference between MIM capacitors and guard ring
Solution Approach 1:
The patent merges the guard ring structure into a shared peripheral arrangement that surrounds multiple MIM capacitors collectively rather than surrounding each capacitor individually. This consolidation reduces the total guard ring perimeter and minimizes the number of guard ring-MIM capacitor interfaces, thereby reducing leakage current while maintaining protective functionality.
Solution Approach 2:
The patent transitions from a distributed one-to-one guard ring arrangement to a consolidated peripheral guard ring structure, changing the spatial dimension of protection from individual cell-level to array-level. This dimensional shift reduces the total interface area between MIM capacitors and guard rings, minimizing leakage current paths.
2Reliability
If guard rings are arranged around each MIM capacitor, then each capacitor is isolated, but the overall footprint of the MIM capacitor array increases
Solution Approach 1:
The patent combines multiple individual guard ring structures into a single shared peripheral guard ring that encloses the entire MIM capacitor array. This merging eliminates redundant guard ring segments and reduces the total area occupied by guard rings, thereby minimizing the footprint while maintaining isolation and protection functionality.
Solution Approach 2:
The shared peripheral guard ring serves multiple functions simultaneously: it provides electrical isolation for all MIM capacitors in the array, acts as a protective barrier against external interference, and defines the overall boundary of the capacitor array. This multi-functionality reduces the need for additional structures, minimizing footprint.
3Reliability
If guard rings are placed between adjacent MIM capacitors, then interference between capacitors is reduced, but the density of MIM capacitors decreases
Solution Approach 1:
The patent merges adjacent individual guard rings into a shared peripheral guard ring structure that encloses multiple MIM capacitors. This consolidation eliminates the need for guard rings between adjacent capacitors, allowing them to be placed closer together and increasing the density of the MIM capacitor array while maintaining interference reduction through the outer peripheral protection.
Data Source
AI summary
In a semiconductor device (SD), plate-shaped upper electrodes (UEL) are formed on a lower electrode (LEL) with a dielectric film (DEC) interposed therebetween. The lower electrode (LEL), the dielectric film (DEC), and the upper electrodes (UEL) constitute MIM capacitors (MCA). One of the upper electrodes (UEL) and another upper electrode (UEL) that are adjacent to each other are arranged at an equal distance (D1), without the guard ring being interposed therebetween. The upper electrodes (UEL) positioned on the outermost periphery and the guard ring (GR) positioned outside those upper electrodes UEL are arranged at a distance equal to the distance (D1) from each other.