Hybrid Supervia Structure for Low-Resistance Hyper-Scaling

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Solution Overview

Problem

The increasing spacing between metal lines in integrated circuits leads to higher coupling capacitance, which negatively impacts signal transmission and energy consumption, and existing subtractive patterning techniques struggle with accurate via alignment and resistance issues.

Innovation Solution

A semiconductor device and method that form a supervia with a damascene lower section and a subtractive upper section, using both techniques to connect non-adjacent interconnect wiring, allowing for a hyper-scaling element that reduces capacitance and resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If metal lines are spaced further apart to avoid interference, then coupling capacitance between adjacent lines is reduced, but the spacing increases which negatively impacts signal transmission and energy consumption

Engineering Contradiction:

Improvecoupling capacitanceVSAvoidenergy consumption

Core Design Contradiction:

Object-generated harmful factorsVSUse of energy by moving object

Solution Approach 1:

The supervia is segmented into two distinct sections: a lower section formed by damascene processing and an upper section formed by subtractive etching. This segmentation allows each section to be optimized for its specific function, with the lower section providing a narrow base for precise alignment and the upper section providing a wider opening for lower resistance, thereby reducing overall energy consumption while maintaining compact spacing

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different sections of the supervia structure are given different properties: the lower section has a narrower width optimized for alignment with underlying features, while the upper section has a wider width optimized for reducing resistance. This local differentiation of properties allows the structure to simultaneously achieve precise positioning and low energy consumption

Inventive Principle:

Principle #3Local quality

2Ease of manufacture

If subtractive patterning is used to form vias, then manufacturing flexibility is improved, but alignment accuracy and resistance control deteriorate

Engineering Contradiction:

Improvemanufacturing flexibilityVSAvoidvia alignment accuracy

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The invention merges two different via formation techniques into a single supervia structure. The lower section is formed using damascene processing which provides excellent alignment accuracy, while the upper section is formed using subtractive etching which provides manufacturing flexibility. The merging of these two approaches allows the structure to achieve both precise alignment and ease of manufacture

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The supervia is divided into two sections with different formation methods: the lower section uses damascene processing for precision, and the upper section uses subtractive etching for flexibility. This segmentation allows each technique to be applied where it is most effective, resolving the contradiction between manufacturing flexibility and alignment accuracy

Inventive Principle:

Principle #1Segmentation

3Device complexity

If a uniform via structure is used throughout, then manufacturing simplicity is maintained, but the ability to optimize for both alignment and resistance is lost

Engineering Contradiction:

Improvevia structure complexityVSAvoidconnection quality

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The via structure employs local quality differentiation with a narrow lower section for alignment optimization and a wider upper section for resistance optimization. This localized variation in dimensions throughout the via structure enhances connection quality while maintaining reasonable manufacturing complexity

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The via is segmented into two sections with different dimensional characteristics: the lower section with smaller width optimized for alignment, and the upper section with larger width optimized for reducing resistance. This segmentation improves overall connection quality while keeping the manufacturing process manageable

Inventive Principle:

Principle #1Segmentation

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

This approach enables a low-resistance connection between non-adjacent interconnects, reduces energy consumption, and avoids minimum-area constraints, facilitating density scaling and efficient signal transmission.

Implementation Method 1

an upper section of a supervia formed via subtractive etching

Methodology Applied

Scientific EffectEtching:

Implementation Method 2

a lower section of the supervia formed via damascene processing

Methodology Applied

Scientific EffectDamascene process:

Data Source

PatentUS11908791B2Partial subtractive supervia enabling hyper-scaling

Publication Date: 2024.02.20 INTERNATIONAL BUSINESS MACHINE CORPORATION

AI summary

A semiconductor device includes an upper section of a supervia formed via subtractive etching and a lower section of the supervia formed via damascene processing. The supervia connects non-adjacent interconnect wiring. The lower section and the upper section of the supervia each define a generally cone-shaped configuration. A distal end of the lower section of the supervia is non-obtuse. Moreover, the lower section of the supervia is formed in a V0 level and the upper section of the supervia is formed in a M1/V1 metallization level.