Hybrid Bonding Alignment Compensation for Differential Thickness

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Solution Overview

Problem

In directly bonded semiconductor structures, achieving reliable electrical connections between finely pitched contact pads is challenging due to misalignment caused by differential expansion and warpage resulting from thickness differences and residual stresses in the bonding layer.

Innovation Solution

The implementation of a lithographic magnification correction factor and a differential expansion compensation structure, such as embedded dielectric layers or patterned metal layers, to compensate for differential expansion and reduce misalignment between contact pads.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If elements of differential thickness are directly bonded, then bonding strength is improved, but misalignment occurs due to differential expansion and warpage

Engineering Contradiction:

Improvebonding strengthVSAvoidalignment precision

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by pre-compensating for differential expansion through lithographic magnification correction factors applied during patterning of the bonding layer. The correction factors are calculated based on expected thickness differences and thermal expansion coefficients, allowing the bonding layer pattern to be pre-adjusted before bonding occurs. This preliminary compensation prevents misalignment from developing during thermal cycling after bonding.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent changes the lithographic magnification parameter as a function of position and thickness differential. By varying the magnification correction factor across different regions of the bonding layer (e.g., higher magnification correction at edges where warpage is greater), the pattern compensates for differential expansion and warpage effects. This parameter change approach allows the same bonding layer to maintain alignment across elements of different thicknesses.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If lithographic magnification correction factor is applied, then alignment precision is improved, but process complexity increases

Engineering Contradiction:

Improvealignment precisionVSAvoidprocess complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces mechanical alignment adjustment mechanisms with a lithographic process parameter adjustment. Instead of using mechanical fixtures or post-bonding alignment tools, the solution embeds the alignment compensation directly into the lithographic patterning step by modifying the magnification factor. This substitution eliminates complex mechanical alignment systems while achieving the same alignment precision through optical/lithographic means.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If elements of different thickness are bonded, then design flexibility is improved, but warpage and misalignment increase

Engineering Contradiction:

Improvedesign flexibilityVSAvoidwarpage

Core Design Contradiction:

Adaptability or versatilityVSShape

Solution Approach 1:

The patent applies local quality by positioning the bonding layer at a specific depth within the element rather than uniformly across the surface. By embedding the bonding layer within the element structure at a location that minimizes its participation in differential expansion and warpage, the design maintains flexibility for different thicknesses while reducing the warpage effect. This local positioning strategy allows elements of varying thickness to bond without excessive warpage.

Inventive Principle:

Principle #3Local quality

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 effectively reduces misalignment and ensures reliable electrical connections across the bonded structure, improving the yield and performance of hybrid direct bonding applications.

Implementation Method 1

differential expansion between a first semiconductor element and a second semiconductor element due to a differential thickness

Methodology Applied

Scientific EffectDifferential expansion: Thermal Expansion

Implementation Method 2

obtaining a lithographic magnification correction factor to compensate for the differential expansion

Methodology Applied

Scientific EffectLithographic magnification:

Data Source

PatentUS12341125B2Dimension compensation control for directly bonded structures

Publication Date: 2025.06.24 ADEIA SEMICONDUCTOR BONDING TECHNOLOGIES INC

AI summary

A method of direct hybrid bonding first and second semiconductor elements of differential thickness is disclosed. The method can include patterning a plurality of first contact features on the first semiconductor element. The method can include second a plurality of second contact features on the second semiconductor element corresponding to the first contact features for direct hybrid bonding. The method can include applying a lithographic magnification correction factor to one of the first patterning and second patterning without applying the lithographic magnification correction factor to the other of the first patterning and the second patterning. In various embodiments, a differential expansion compensation structure can be disposed on at least one of the first and the second semiconductor elements. The differential expansion compensation structure can be configured to compensate for differential expansion between the first and second semiconductor elements to reduce misalignment between at least the second and fourth contact features.