Linerless Diamond Skip-Via Structure for Lower Vertical Resistance

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Nanosheet technology faces issues with increased vertical resistance in skip-vias due to liners between the skip-vias and surrounding materials, which interfere as devices scale down and become closer together.

Innovation Solution

A microelectronic structure is formed without a liner between the skip-via sidewall and surrounding material, with angled sidewalls in a diamond-shaped skip-via design, where the bottom section's width increases from the bottom to the top, and the top section's width decreases from the bottom to the top, reducing resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a liner is formed on the outside surface of the skip-via, then the skip-via is protected from surrounding material, but the vertical resistance of the skip-via increases

Engineering Contradiction:

Improveskip-via protectionVSAvoidvertical resistance

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent removes the liner layer from the skip-via structure entirely, extracting the harmful element that was causing increased vertical resistance. The skip-via is formed without any liner material on its outside surface, eliminating the resistance issue while maintaining structural integrity through alternative protective measures.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of adding a liner to protect the skip-via (traditional approach), the patent inverts the approach by forming the skip-via without a liner and using the surrounding dielectric material and processing conditions to provide the necessary protection and definition. This inversion eliminates the resistance problem while achieving the protective function through different means.

Inventive Principle:

Principle #13The other way round (Inversion)

2Productivity

If devices are scaled down and placed closer together, then device density increases, but interference between adjacent devices increases

Engineering Contradiction:

Improvedevice densityVSAvoiddevice interference

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies different properties to different regions: the skip-via has a linerless structure with specific angled sidewalls in high-interference regions, while other areas maintain traditional structures. This localized optimization reduces interference between closely-spaced devices while maintaining overall device density and functionality.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent introduces angular dimensions to the skip-via sidewalls (first angle and second angle relative to vertical) as an additional degree of freedom for controlling device interaction. By varying the sidewall angles, the patent optimizes the spatial distribution of electric fields and reduces interference between adjacent scaled-down devices.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS20240162139A1Method and structure of forming barrier-less skip via with subtractive metal patterning

Publication Date: 2024.05.16 INTERNATIONAL BUSINESS MACHINE CORPORATION

AI summary

A microelectronic structure including a first metal line, a second metal line, and a third metal line. A skip-via connecting the first metal line to the third metal line, where the skip-via includes a bottom section and a top section. A bottom sidewall of the bottom section is at a first angle and a top sidewall of the top section are at a second angle, where the first angle and the second angle are opposite from each other.