MIM Capacitor Amorphous Dielectric Layer Grain Boundary Blocking
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Solution Overview
Problem
High-k dielectric materials in MIM capacitors have low energy band-gaps, leading to increased time-dependent dielectric breakdown and reliability issues due to the formation of grain boundaries, which can cause leakage paths between metal layers.
Innovation Solution
A multi-layer capacitor dielectric layer comprising an amorphous dielectric layer abutting a high-k dielectric layer, which prevents the propagation of grain boundaries and enhances dielectric breakdown, thereby improving the reliability and capacitance density of MIM capacitors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high-k dielectric materials are used in MIM capacitors, then capacitance density is improved, but time-dependent dielectric breakdown increases and reliability deteriorates
Solution Approach 1:
The patent employs a composite dielectric structure consisting of a high-k dielectric layer combined with an amorphous dielectric layer. The high-k layer provides high capacitance density while the amorphous layer with larger bandgap prevents grain boundary formation and dielectric breakdown, thus resolving the contradiction between capacitance density and reliability.
Solution Approach 2:
The patent applies different dielectric materials with different properties to different regions of the capacitor structure. The high-k dielectric material is used where high capacitance is needed, while the amorphous dielectric material with larger bandgap is used where reliability and prevention of dielectric breakdown are critical, achieving local optimization of both capacitance and reliability.
2Quantity of substance
If high-k dielectric materials are used in MIM capacitors, then capacitance density is improved, but grain boundary formation increases causing leakage paths
Solution Approach 1:
The amorphous dielectric layer acts as an intermediary between the high-k dielectric layer and the metal electrodes. It prevents grain boundary formation and propagation in the high-k layer by providing a matrix with larger bandgap that does not support grain boundary development, thus eliminating the harmful leakage paths while preserving the high capacitance density.
Solution Approach 2:
The patent changes the material parameter (bandgap energy) by introducing an amorphous dielectric layer with larger bandgap than the crystalline high-k dielectric. This parameter change prevents the formation of leakage paths through grain boundaries while maintaining the high capacitance density provided by the high-k material.
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 amorphous dielectric layer with a larger band gap effectively blocks grain boundary formation, reducing leakage and enhancing the reliability and capacitance density of MIM capacitors, addressing the reliability issues associated with high-k dielectric materials.
Implementation Method 1
The amorphous dielectric layer with a larger band gap effectively blocks grain boundary formation
Implementation Method 2
prevents the propagation of grain boundaries and enhances dielectric breakdown
Implementation Method 3
MIM capacitors may be used as decoupling capacitors configured to mitigate power supply or switching noise
Data Source
AI summary
The present disclosure relates to a MIM (metal-insulator-metal) capacitor having a multi-layer capacitor dielectric layer including an amorphous dielectric layer configured to mitigate the formation of leakage paths, and a method of formation. In some embodiments, the MIM (metal-insulator-metal) capacitor has a capacitor bottom metal layer. A multi-layer capacitor dielectric layer is disposed over the capacitor bottom metal layer. The multi-layer capacitor dielectric layer has an amorphous dielectric layer abutting a high-k dielectric layer. A capacitor top metal layer is disposed over the multi-layer capacitor dielectric layer. The high-k dielectric layer within the capacitor dielectric layer provides the MIM capacitor with a high capacitance density, while the amorphous dielectric layer prevents leakage by blocking the propagation of grain boundaries between the capacitor top metal layer and the capacitor bottom metal layer.