Dielectric Anchor Structure for Isolated Conductive Pillars

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Solution Overview

Problem

The mechanical strength of conductive pillars in 3D integrated circuits is compromised by air trenches, leading to potential failure during fabrication and consumer use, affecting yield and device performance.

Innovation Solution

The conductive pillars are anchored to the semiconductor substrate via dielectric anchors, which provide both electrical isolation and structural support, preventing cracking and dislodging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If air trenches are used for electrical isolation, then electrical isolation is improved, but mechanical strength deteriorates

Engineering Contradiction:

Improveelectrical isolationVSAvoidmechanical strength

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

A dielectric anchor structure is introduced as an intermediary element between the conductive pillar and the air trench. The dielectric anchor provides mechanical support to the conductive pillar while allowing the air trench to maintain its electrical isolation function, thus resolving the contradiction between mechanical strength and electrical isolation.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The solution employs a composite structure combining dielectric material (for mechanical support and electrical isolation) and air (for electrical isolation). The dielectric anchor made of solid dielectric material works in conjunction with the air trench to provide both mechanical strength and electrical isolation, addressing the contradiction through material composition.

Inventive Principle:

Principle #40Composite materials

2Productivity

If conductive pillars are made thinner for scaling, then device density is improved, but mechanical robustness deteriorates

Engineering Contradiction:

Improvedevice densityVSAvoidmechanical robustness

Core Design Contradiction:

ProductivityVSStrength

Solution Approach 1:

The dielectric anchor provides localized mechanical support specifically at the interface between the conductive pillar and the substrate. This local reinforcement allows the conductive pillar to be thinner for scaling while maintaining overall mechanical robustness through targeted support where it is most needed.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The dielectric anchor acts as a pre-established support structure that cushions and protects the conductive pillar from mechanical stresses during fabrication and operation. This beforehand cushioning enables thinner pillars to maintain robustness by having protective support in place before stress events occur.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentUS20250316574A1Dielectric anchors for anchoring a conductive pillar

Publication Date: 2025.10.09 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

Various embodiments of the present disclosure are directed towards an apparatus comprising a semiconductor substrate. A conductive pillar is disposed in the semiconductor substrate. An isolation region is disposed in the semiconductor substrate and extends laterally around the conductive pillar. The isolation region is configured to electrically isolate the conductive pillar from a surrounding portion of the semiconductor substrate. An opening is disposed in the isolation region. A dielectric anchor is disposed in the isolation region. The dielectric anchor extends vertically through the first semiconductor substrate along a side of the opening. The dielectric anchor anchors the conductive pillar to the semiconductor substrate.