Stacked Capacitor Structure for High Capacitance on Conductive Substrates
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing capacitors face constraints on size and substrate limitations due to their structure, particularly those using multiple dielectric layers and conductors.
Innovation Solution
A capacitor design with a substrate having electrical conductivity, a first dielectric layer, a first conductor, a second dielectric layer, and a second conductor, where the first conductor has an exposed portion not covered by the second dielectric or conductor, and the substrate is insulated by the first dielectric layer, allowing for electrical connection to the second conductor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a capacitor uses multiple dielectric layers and multiple conductors stacked on top of one another, then the capacitance increases, but the device complexity and manufacturing constraints increase
Solution Approach 1:
The capacitor is divided into multiple functional layers (first dielectric layer, first conductor, second dielectric layer, second conductor) stacked alternately, with each layer serving a specific electrical function. This segmentation allows independent optimization of each layer's properties while achieving high overall capacitance
Solution Approach 2:
The capacitor structure embeds multiple conductors and dielectric layers within each other in a nested configuration, where the first conductor is surrounded by dielectric layers, and the second conductor is positioned to interact with the first conductor through the dielectric insulation, creating a compact multi-element structure
2Quantity of substance
If the capacitor uses a trench structure with pillars in a substrate, then the capacitance increases, but the substrate constraints and manufacturing difficulty increase
Solution Approach 1:
The invention extracts the capacitor structure from the substrate and forms it as a separate stacked assembly. The conductors and dielectric layers are formed independently and then assembled, eliminating the need for complex trench etching and pillar formation within the substrate
Solution Approach 2:
The capacitor transitions from a planar trench structure to a vertical stacked structure, utilizing the third dimension (height) for layer stacking. This dimensional change allows high capacitance to be achieved through vertical integration rather than horizontal expansion within substrate trenches
3Reliability
If the capacitor uses high-resistance silicon substrate or doped silicon wafer, then the electrical performance improves, but the substrate selection is limited
Solution Approach 1:
The capacitor structure is designed to be substrate-agnostic, working effectively with various substrate types including but not limited to high-resistance silicon, low-resistance silicon, and other conductive substrates. The first dielectric layer provides universal electrical insulation functionality regardless of substrate type
Solution Approach 2:
The first dielectric layer acts as an intermediary between the substrate and the first conductor, providing electrical insulation that decouples the capacitor structure from substrate-specific electrical characteristics. This intermediary layer enables the same capacitor design to function on diverse substrate types
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 design offers reduced constraints on size and substrate while maintaining high capacitance, durability, and reliability, with the ability to use various conductive materials and processes beyond semiconductor MOS processes.
Implementation Method 1
the substrate is electrically insulated from the first conductor by the first dielectric layer
Implementation Method 2
the second conductor is electrically insulated from the first conductor by the second dielectric layer
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
A capacitor includes: a substrate having electrical conductivity; a first dielectric layer disposed on the substrate; a first conductor disposed on the first dielectric layer and having a layer shape; a second dielectric layer disposed on the first conductor; and a second conductor disposed on the second dielectric layer. The first conductor includes an exposed portion that is covered by neither the second dielectric layer nor the second conductor. The substrate is electrically insulated from the first conductor by the first dielectric layer, and the second conductor is electrically insulated from the first conductor by the second dielectric layer. The substrate includes a conductive portion electrically connected to the second conductor.