Semiconductor Interconnect Structure With Air Gap and Split Barrier Layers

Solution Overview

Problem

As semiconductor industry advances, the increased density and reduced dimensions of integrated circuits lead to increased capacitive coupling between conductive features, resulting in higher power consumption and longer RC time constants due to increased capacitance between adjacent conductive elements.

Innovation Solution

The implementation of an interconnection structure with separate barrier layers on neighboring conductive features, an air gap between them, and a metal oxide layer to prevent line-to-line leakage and capacitive coupling, achieved through a series of processing steps including forming openings, applying blocking and barrier layers, and creating an air gap to reduce capacitive coupling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the distance between adjacent conductive features is reduced to increase density, then the device functionality and density are improved, but the capacitance between conductive features increases leading to higher power consumption

Engineering Contradiction:

Improvedevice densityVSAvoidpower consumption

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

A dielectric layer with low dielectric constant (k-value) is introduced as an intermediary material between adjacent conductive features. This intermediary layer reduces the capacitive coupling between conductors while maintaining the reduced spacing required for high device density, thereby lowering power consumption without sacrificing productivity

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The dielectric constant (k-value) parameter of the insulating material is changed to a lower value to reduce capacitance. By selecting and implementing materials with lower dielectric constants between conductive features, the patent reduces capacitive coupling effects while maintaining the physical layout required for high-density integration

Inventive Principle:

Principle #35Parameter changes

2Productivity

If the distance between adjacent conductive features is reduced to increase density, then the device functionality and density are improved, but the RC time constant increases due to increased capacitance

Engineering Contradiction:

Improvedevice densityVSAvoidRC time constant

Core Design Contradiction:

ProductivityVSLoss of time

Solution Approach 1:

A dielectric layer with low dielectric constant (k-value) is introduced as an intermediary material between adjacent conductive features. This intermediary layer reduces the capacitive coupling between conductors while maintaining the reduced spacing required for high device density, thereby lowering power consumption without sacrificing productivity

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The dielectric constant (k-value) parameter of the insulating material is changed to a lower value to reduce capacitance. By selecting and implementing materials with lower dielectric constants between conductive features, the patent reduces capacitive coupling effects while maintaining the physical layout required for high-density integration

Inventive Principle:

Principle #35Parameter changes

3Productivity

If conductive features are placed closer together to increase density, then the device functionality is improved, but line-to-line leakage and capacitive coupling increase

Engineering Contradiction:

Improvedevice densityVSAvoidsignal integrity

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

A dielectric layer with low dielectric constant (k-value) is introduced as an intermediary material between adjacent conductive features. This intermediary layer reduces the capacitive coupling between conductors while maintaining the reduced spacing required for high device density, thereby lowering power consumption without sacrificing productivity

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

Air gaps are created by removing dielectric material in specific regions between conductive features. This extraction of material creates regions with minimal dielectric constant (approximately 1 for air/vacuum), effectively reducing capacitive coupling and preventing leakage currents while maintaining the close spacing needed for high density

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentUS12033889B2Semiconductor device structure and methods of forming the same

Publication Date: 2024.07.09 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

An interconnection structure, along with methods of forming such, are described. The structure includes a dielectric layer, a first conductive feature disposed in the dielectric layer, and a conductive layer disposed over the dielectric layer. The conductive layer includes a first portion and a second portion adjacent the first portion, and the second portion of the conductive layer is disposed over the first conductive feature. The structure further includes a first barrier layer in contact with the first portion of the conductive layer, a second barrier layer in contact with the second portion of the conductive layer, and a support layer in contact with the first and second barrier layers. An air gap is located between the first and second barrier layers, and the dielectric layer and the support layer are exposed to the air gap.