Hybrid Bonding Pads for 3DIC Alignment-Tolerant Interconnects

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Solution Overview

Problem

Poor alignment between stacked semiconductor dies in 3DICs leads to conductivity defects due to misplacement of interconnects, and achieving perfect alignment is inefficient and time-consuming.

Innovation Solution

The integration of expanding pads with increased contact areas on conductive portions of substrates, using aluminum fluoride barrier layers, and a hybrid bonding process to enhance conductivity and reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If perfect alignment is pursued during semiconductor manufacturing, then alignment precision is improved, but process time increases significantly

Engineering Contradiction:

Improvealignment precisionVSAvoidprocess time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent applies preliminary action by forming expanding pads on the first substrate before bonding to the second substrate. These pre-formed pads create a larger contact area that compensates for potential misalignment during the bonding process, eliminating the need for perfect alignment while maintaining conductivity reliability.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If expanding pads with larger contact areas are formed, then conductivity reliability is improved, but device structure becomes more complex

Engineering Contradiction:

Improveconductivity reliabilityVSAvoidbonding structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The expanding pads serve multiple functions: they provide a larger contact area for improved alignment tolerance, act as a bonding interface between substrates, and maintain electrical conductivity. This multi-functionality reduces the need for additional specialized components, thereby limiting the increase in device complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Device complexity

If conventional bonding without expanding pads is used, then device structure remains simple, but conductivity defects occur due to poor alignment

Engineering Contradiction:

Improvebonding structure simplicityVSAvoidconductivity reliability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The expanding pads are formed in advance on the first substrate before bonding occurs. This preliminary action creates a robust bonding interface that tolerates misalignment, preventing conductivity defects without requiring complex real-time alignment mechanisms during the bonding process.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS12538781B2Method of manufacturing integrated circuit device with bonding structure

Publication Date: 2026.01.27 NAN YA TECH

AI summary

A circuit device includes: a first substrate having a first barrier layer; a second substrate having a second barrier layer; a first conductive portion arranged over the first barrier layer; a second conductive portion arranged over the second barrier layer; a first expanding pad arranged on the first conductive portion and including a first contact area greater than that of the first conductive portion; and a second expanding pad bonded to the first expanding pad, arranged on the second conductive portion and including a second expanded contact area greater than that of the second conductive portion. The first barrier layer and the second barrier layer include aluminum fluoride.