Embedded Bridge Protection Layer for Clean Via Formation

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Solution Overview

Problem

The challenge of maintaining via integrity, particularly via bottom critical dimension, taper angle, and cleanliness, is exacerbated by the scaling of bump pitch in electronic packaging, leading to issues like foreign material trapping and electromigration, which complicates fabrication and increases yield loss.

Innovation Solution

Implementing a protective layer over the pads to shield them from laser ablation, preventing localized melting and foreign material trapping, while also acting as a copper migration barrier, thus improving the adhesion and reducing electromigration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If laser drilling operations are used to form vias, then via bottom critical dimension and taper angle are controlled, but cleanliness at the bottom of the via is difficult to obtain

Engineering Contradiction:

Improvevia bottom critical dimension and taper angleVSAvoidcleanliness at the bottom of the via

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

A protective layer is applied to the pad surface before laser via formation. This preliminary action prevents foreign material contamination during the laser drilling process, eliminating the need for subsequent cleaning processes while maintaining via bottom cleanliness.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The protective layer acts as an intermediary between the laser drilling process and the pad material. It prevents direct interaction that would cause foreign material trapping, while still allowing the laser to effectively form the via through the protective layer.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If additional cleaning processes are implemented to improve via cleanliness, then via integrity is improved, but fabrication complexity and time increase

Engineering Contradiction:

Improvevia integrityVSAvoidfabrication process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The protective layer approach extracts the contamination prevention function from the complex multi-step cleaning process sequence. By preventing contamination upfront, it eliminates the need for wet and/or dry etching processes and copper pad surface treatment, simplifying the overall fabrication process.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The protective layer is applied in advance to prevent foreign material contamination, eliminating the need for subsequent cleaning steps. This preliminary protective action reduces fabrication complexity and extends the time needed for fabrication while maintaining via integrity.

Inventive Principle:

Principle #10Preliminary action

3Length of moving object

If bump pitch is scaled down to enable smaller devices, then device size is reduced, but foreign material trapping and electromigration increase

Engineering Contradiction:

Improvebump pitchVSAvoidvia integrity

Core Design Contradiction:

Length of moving objectVSReliability

Solution Approach 1:

The protective layer serves as an intermediary that prevents foreign material trapping at the pad-via interface, which becomes more critical as bump pitch scales down. It also acts as a barrier to copper migration, addressing electromigration issues that arise with reduced spacing between vias.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The protective layer is selectively applied to the pad areas where vias will be formed. This local application provides targeted protection against foreign material trapping and electromigration at critical interfaces, while allowing the rest of the structure to maintain its scaled-down dimensions.

Inventive Principle:

Principle #3Local quality

4Reliability

If protective layer is applied to prevent foreign material trapping, then via cleanliness is improved, but fabrication process becomes more complex

Engineering Contradiction:

Improvevia cleanlinessVSAvoidfabrication process

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The protective layer is applied as a preliminary step before via formation. This single upfront action prevents foreign material trapping during laser drilling, eliminating the need for multiple subsequent cleaning processes (wet and/or dry etching, copper pad surface treatment) and reducing overall fabrication complexity.

Inventive Principle:

Principle #10Preliminary action

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 protective layer ensures cleaner via openings, reduces fabrication time and cost, and enhances device reliability by minimizing electrical shorts and electromigration.

Implementation Method 1

shield them from laser ablation, preventing localized melting

Methodology Applied

Scientific EffectLaser ablation: Laser Ablation

Implementation Method 2

preventing localized melting

Methodology Applied

Scientific EffectMelting: Melting

Implementation Method 3

acting as a copper migration barrier, thus improving the adhesion and reducing electromigration

Methodology Applied

Scientific EffectElectromigration:

Data Source

PatentUS20260005173A1Embedded bridge with protection layer for via formation with bump pitch scaling

Publication Date: 2026.01.01 INTEL CORP

AI summary

Embodiments disclosed herein include an apparatus that comprises a substrate with a component in the substrate, where the component comprises a pad. In an embodiment, a first layer is over the pad, and the first layer comprises silicon and nitrogen. In an embodiment, a second layer is over the substrate, and a via that passes through the first layer and the second layer, where the via contacts the pad.