Metal-Insulator-Metal Capacitor Structures for Integrated Voltage Handling
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Solution Overview
Problem
Current metal-insulator-metal (MIM) capacitor structures can only support either high-voltage capacitors with low capacitance density or low-voltage capacitors with high capacitance density, making it difficult to integrate both types on the same chip effectively, as the thickness of the dielectric layer affects both voltage withstand and capacitance density.
Innovation Solution
A capacitor structure using three metal layers, where a low-voltage capacitor with high capacitance density and a high-voltage capacitor with thick dielectric are implemented on the same chip, with the low-voltage capacitor utilizing all three metal layers and the high-voltage capacitor using the first and third metal layers without the middle layer, allowing for increased capacitance density and voltage withstand.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thick dielectric layer is used in MIM capacitor, then voltage withstand is improved, but capacitance density deteriorates
Solution Approach 1:
The capacitor structure is segmented into multiple dielectric layers (first dielectric layer and second dielectric layer) with different thicknesses. The first dielectric layer has greater thickness for voltage withstand, while the second dielectric layer has lesser thickness for capacitance density, dividing the single dielectric layer into functional segments.
Solution Approach 2:
Different regions of the dielectric structure have different thicknesses to serve different functions. The first dielectric layer region provides high voltage withstand capability, while the second dielectric layer region provides high capacitance density, creating local quality variations within the overall capacitor structure.
2Quantity of substance
If a thin dielectric layer is used in MIM capacitor, then capacitance density is improved, but voltage withstand deteriorates
Solution Approach 1:
The capacitor structure is segmented into multiple dielectric layers (first dielectric layer and second dielectric layer) with different thicknesses. The first dielectric layer has greater thickness for voltage withstand, while the second dielectric layer has lesser thickness for capacitance density, dividing the single dielectric layer into functional segments.
Solution Approach 2:
Different regions of the dielectric structure have different thicknesses to serve different functions. The first dielectric layer region provides high voltage withstand capability, while the second dielectric layer region provides high capacitance density, creating local quality variations within the overall capacitor structure.
3Ease of manufacture
If traditional MIM capacitor structure is used, then manufacturing simplicity is maintained, but versatility in supporting both high-voltage and low-voltage capacitors deteriorates
Solution Approach 1:
The capacitor structure uses three metal layers (first, second, and third metal layers) that can be configured to form both high-voltage capacitors (using first and third metal layers) and low-voltage capacitors (using second metal layer with either first or third metal layer), making the structure universal for both applications.
Solution Approach 2:
The invention adds a vertical dimension to the capacitor structure by introducing multiple dielectric layers at different vertical positions between metal layers, enabling the same structure to provide different electrical characteristics for high-voltage and low-voltage applications.
Data Source
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AI summary
Capacitor structures capable of providing both low-voltage capacitors and high-voltage capacitors are described herein. In one embodiment, a capacitor structure comprises a low-voltage capacitor and a high-voltage capacitor. The low-voltage capacitor comprises a first electrode formed from a first metal layer, a second electrode formed from a second metal layer, a third electrode formed from a third metal layer, a first dielectric layer between the first and second electrodes, and a second dielectric layer between the second and third electrodes. The high-voltage capacitor comprises a fourth electrode formed from the first metal layer, a fifth electrode formed from the third metal layer, and a third dielectric layer between the fourth and fifth electrodes, wherein the third dielectric layer is thicker than either the first dielectric layer or the second dielectric layer.