Trench MIM Capacitor Layout for Stable Electrodes and Copper Blocking
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Solution Overview
Problem
Existing MIM capacitors in integrated circuits face challenges in stability and performance, necessitating improvements to enhance chip efficiency.
Innovation Solution
A trench is embedded within inter-metal dielectrics, filled with a silicon oxide liner, and a capacitor structure comprising a first and second electrode layer with a capacitor dielectric layer in between, using flowable chemical vapor deposition to ensure even sidewall coverage and prevent copper diffusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional MIM capacitor structures are used in integrated circuits, then the fabrication process is compatible with integrated circuit manufacturing, but the stability and performance of the capacitors are insufficient
Solution Approach 1:
The capacitor structure is divided into distinct functional segments: a trench region containing the capacitor stack (first electrode layer, capacitor dielectric layer, second electrode layer), and surrounding inter-metal dielectric regions. This segmentation isolates the capacitor components, improving stability while maintaining fabrication compatibility.
Solution Approach 2:
An intermediate layer is introduced between the capacitor electrodes and the surrounding inter-metal dielectrics. This intermediate layer acts as a mediator that enhances the stability of the capacitor structure and prevents unwanted interactions between the capacitor components and the surrounding dielectric material.
2Reliability
If electrode layers are formed to fill the trench, then the capacitor structure is complete, but copper diffusion may occur compromising capacitor performance
Solution Approach 1:
An intermediate barrier layer is positioned between the copper-containing electrode layers and the surrounding environment. This intermediate layer serves as a diffusion barrier that prevents copper atoms from migrating out of the capacitor structure, thereby maintaining capacitor performance without requiring excessive protective layers.
Solution Approach 2:
The capacitor structure employs composite material layers with different functional properties. The electrode layers use copper for low resistance, while the intermediate layer uses materials with copper-diffusion-blocking properties. This composite approach achieves copper diffusion prevention while maintaining the electrical performance benefits of copper electrodes.
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 solution enhances the stability and performance of MIM capacitors by ensuring continuous electrode layer formation and preventing copper diffusion, thereby improving chip efficiency.
Implementation Method 1
a flowable chemical vapor deposition is performed to form a silicon oxide liner covering and contacting the trench and covering and contacting a topmost surface of the inter-metal dielectrics
Data Source
AI summary
An MIM capacitor structure includes numerous inter-metal dielectrics. A trench is embedded within the inter-metal dielectrics. A capacitor is disposed within the trench. The capacitor includes a first electrode layer, a capacitor dielectric layer and a second electrode layer. The first electrode layer, the capacitor dielectric layer and the second electrode layer fill in and surround the trench. The capacitor dielectric layer is between the first electrode layer and the second electrode layer. A silicon oxide liner surrounds a sidewall of the trench and contacts the first electrode layer.