Multilayer Trench Conductor Structure for High-Frequency Skin Effect

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Traditional copper wires experience significant resistive loss due to the skin effect at high frequencies, which complicates the production process of multilayered conductors with ferromagnetic and non-magnetic layers when sidewall-deposited material removal is required.

Innovation Solution

A conductor design with a stack of ferromagnetic and non-magnetic layers conformally extending along the trench base and sidewalls, eliminating the need for sidewall layer removal, and utilizing a damascene-type process compatible with industrial environments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If traditional copper wires are used for high frequency signal transfer, then the conductor structure is simple and easy to manufacture, but resistive loss increases significantly due to the skin effect

Engineering Contradiction:
Improveconductor structure simplicityVSAvoidresistive loss
Core Design Contradiction:
Ease of manufactureVSLoss of energy

Solution Approach 1:

The patent applies composite materials by creating a multilayered conductor structure consisting of alternating ferromagnetic and non-magnetic layers. This composite structure suppresses the skin effect at high frequencies while maintaining manufacturability through a damascene-type process that deposits consecutive layers in a trench without requiring sidewall material removal.

Inventive Principle:
Principle #40Composite materials

2Loss of energy

If multilayered metaconductors are produced by lift-off process to suppress skin effect, then resistive loss is reduced at high frequencies, but the production process becomes significantly more complex due to sidewall material removal

Engineering Contradiction:
Improveresistive lossVSAvoidproduction process complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent extracts the problematic step of sidewall material removal from the production process. By using a damascene-type process where consecutive ferromagnetic and non-magnetic layers are deposited directly in the trench, the method eliminates the complex lift-off process while maintaining the beneficial skin effect suppression of multilayered metaconductors.

Inventive Principle:
Principle #2Taking out (Extraction)

3Loss of energy

If thick stacks of ferromagnetic and non-magnetic layers are used to suppress skin effect, then resistive loss is reduced, but the conductor width increases and manufacturing precision requirements increase

Engineering Contradiction:
Improveresistive lossVSAvoidlayer thickness control
Core Design Contradiction:
Loss of energyVSManufacturing precision

Solution Approach 1:

The patent optimizes the parameters of the multilayered structure by controlling the thickness of individual ferromagnetic and non-magnetic layers. By adjusting these parameters, the invention achieves effective skin effect suppression with a manageable total stack thickness that fits within standard conductor dimensions and manufacturing capabilities.

Inventive Principle:
Principle #35Parameter changes

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 conductor effectively suppresses the skin effect at high frequencies, maintaining low resistance across a wide frequency range without the complexity of sidewall layer removal, using a thin stack that is less than 30% of the conductor's width.

Implementation Method 1

Traditional conductors such as copper wires however suffer from increased resistive loss at these high frequencies as a consequence of the skin effect

Methodology Applied
Scientific EffectSkin effect: Skin Effect

Data Source

PatentEP4607591A1A semiconductor component including one or more conductors comprising a stack of ferromagnetic and nonmagnetic materials
Publication Date: 2025.08.27 INTERUNIVERSITAIR MICRO ELECTRONICS CENT (IMEC VZW)
  • EP4607591A1 patent drawingFigure 1~2
  • EP4607591A1 patent drawingFigure 3~4
  • EP4607591A1 patent drawingFigure 5~6

AI summary

In a component according to the invention, for example an integrated circuit chip or an interposer chip (2), a dielectric layer (5) is provided having a planar upper surface (9) and a first trench (10) formed through the upper surface, the trench having a base (11) and upstanding sidewalls (12). A conductor (4) is arranged in the trench, the conductor comprising a stack (14) formed of alternately stacked non-magnetic layers and ferromagnetic layers (15,16). The stack conformally follows the base and sidewalls of the trench. In other words, the stack extends along said base and sidewalls, so that the stack itself defines an inner trench (17), i.e. a second trench inside the first trench. The second trench is filled with a central portion (18) of electrically conductive material. The presence of the stack (14) of ferromagnetic and non-magnetic layers suppresses the skin effect at high frequencies. The presence of the stack on the sidewalls of the first trench does not deteriorate the suppression of the skin effect in a largely applicable frequency range.