Metal Trench Decoupling Capacitor for Power Noise Suppression

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Solution Overview

Problem

As semiconductor elements with different functions generate varying types of signals, they often interfere with each other due to power noise, which increases with rising operational frequencies and power domains, necessitating a solution to minimize or eliminate this interference while being compatible with current semiconductor manufacturing processes.

Innovation Solution

A metal trench de-coupling capacitor structure is introduced, featuring a substrate with a vertical trench and insulating layer, filled with an inter-metal connection layer electrically connected to power, utilizing a dual damascene process to form a deep metal trench that suppresses power noise by acting as a de-coupling capacitor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a deep metal trench de-coupling capacitor structure is implemented to suppress power noise, then power noise suppression is improved, but device complexity increases

Engineering Contradiction:

Improvepower noise suppressionVSAvoidstructure complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The metal trench de-coupling capacitor structure is nested within the existing semiconductor device architecture. The vertical trench is formed within the substrate, and the inter-metal connection layer is embedded within the trench, creating a compact nested structure that integrates noise suppression functionality without adding external components or significantly increasing overall device complexity.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The invention transitions from traditional planar de-coupling capacitor designs to a vertical three-dimensional structure. By forming a vertical trench that extends deep into the substrate and filling it with conductive material, the solution utilizes the vertical dimension to create effective de-coupling capacitance, thereby suppressing power noise while maintaining footprint efficiency and managing structural complexity.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Power

If operational frequencies and power domains are increased to meet performance requirements, then device performance is improved, but power noise increases

Engineering Contradiction:

Improvedevice performanceVSAvoidpower noise

Core Design Contradiction:

PowerVSObject-generated harmful factors

Solution Approach 1:

The invention converts the harmful effect of power noise generated by high-frequency operation into a beneficial de-coupling effect. By strategically placing metal trench de-coupling capacitors near noise-sensitive regions, the power noise and voltage pulses generated during high-frequency operation are captured and suppressed by the de-coupling capacitance, thereby transforming the harmful noise into a controlled electrical phenomenon that protects sensitive circuits.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Ease of manufacture

If traditional de-coupling methods are used, then manufacturing process compatibility is maintained, but power noise suppression effectiveness is insufficient

Engineering Contradiction:

Improveprocess compatibilityVSAvoidpower noise suppression

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The invention merges the de-coupling capacitor formation process with the existing dual damascene metal interconnection fabrication process. The vertical trench is formed and filled with the same metal deposition and planarization steps already established in the manufacturing flow, thereby maintaining full process compatibility while achieving superior power noise suppression compared to traditional separate de-coupling capacitor implementations.

Inventive Principle:

Principle #5Merging (Combining)

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 metal trench de-coupling capacitor effectively reduces abnormal voltage pulses and power noise, ensuring minimal interference between different semiconductor elements, thereby maintaining signal integrity across various circuit types.

Implementation Method 1

a metal trench de-coupling capacitor structure to avoid the interference of power noise... The inter-metal connection layer is disposed in the inter-metal dielectric layer and penetrates the interlayer dielectric layer

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS9466526B2Metal trench decoupling capacitor structure penetrating through a shallow trench isolation

Publication Date: 2016.10.11 REALTEK SEMICON CORP

AI summary

A metal trench de-coupling capacitor structure includes a vertical trench disposed in a substrate, an insulating layer deposited on the sidewall of the vertical trench, an inter-layer dielectric layer covering the substrate and the insulating layer, and a metal layer penetrating the interlayer dielectric layer to fill up the vertical trench. The metal layer is electrically connected to a power source.