Stacked Hybrid IC Assembly for Dense Photonic-Electronic Integration

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Solution Overview

Problem

Integrating photonic and electronic components in integrated circuits is challenging due to limitations in optical component density and the difficulty in forming uniform monocrystalline layers, which affects signal propagation and thermal management.

Innovation Solution

The solution involves separately fabricating monocrystalline layers for optical components and using layer transfer to stack them, incorporating isolation layers with different refractive indices to prevent signal leakage, and integrating electronic components, all while maintaining a uniform crystal structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If monocrystalline layers are formed using conventional methods, then uniform crystal structure is achieved, but optical component density is limited

Engineering Contradiction:
Improveuniform crystal structureVSAvoidoptical component density
Core Design Contradiction:
Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The patent transitions from planar integration to three-dimensional vertical stacking of monocrystalline layers. Multiple optical components are integrated across stacked layers with different orientations (e.g., first layer in x-y plane, second layer in x-z plane), enabling increased component density while preserving crystal uniformity through separate layer fabrication and bonding.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent divides the optical circuit into multiple separate monocrystalline layers that are fabricated independently and then bonded together. Each layer can be optimized separately for uniform crystal structure, and the segmentation allows vertical stacking to increase overall component density without compromising the quality of individual layers.

Inventive Principle:
Principle #1Segmentation

2Quantity of substance

If multiple monocrystalline layers are stacked vertically, then optical component density increases, but signal leakage between layers occurs

Engineering Contradiction:
Improveoptical component densityVSAvoidsignal propagation
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent introduces intermediate layers between stacked monocrystalline layers to prevent signal leakage. These intermediate layers act as mediators that optically isolate adjacent monocrystalline layers while allowing mechanical bonding, thus preventing crosstalk and signal leakage between layers with different orientations.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent extracts the isolation function into separate intermediate layers that are distinct from the monocrystalline layers. By separating the optical signal confinement function into dedicated intermediate layers, the patent prevents signal leakage between monocrystalline layers while maintaining their individual optical pathways.

Inventive Principle:
Principle #2Taking out (Extraction)

3Adaptability or versatility

If photonic and electronic components are integrated on the same substrate, then device functionality is enhanced, but thermal management becomes difficult

Engineering Contradiction:
Improvedevice functionalityVSAvoidthermal management
Core Design Contradiction:
Adaptability or versatilityVSTemperature

Solution Approach 1:

The patent segments photonic and electronic components into separate functional layers. Photonic components are integrated in monocrystalline layers with optical pathways, while electronic components are placed in separate layers or regions, allowing independent thermal management strategies for each component type and preventing thermal interference.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by providing region-specific thermal management solutions. Heat dissipation structures, cooling channels, or thermal vias are strategically positioned in regions with high electronic component density, while photonic regions maintain their optical properties, enabling effective thermal management without compromising overall device functionality.

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 enables the creation of vertically-stacked hybrid ICs with increased optical component density and improved signal propagation, addressing thermal constraints and enhancing bandwidth between dies.

Implementation Method 1

a bonding material, different from the first monocrystalline material and the second monocrystalline material, bonding the first optical layer and the second optical layer to one another

Methodology Applied
Scientific EffectBonding: Welding

Implementation Method 2

A first monocrystalline layer and a second monocrystalline layer are layer transferred and stacked onto one another to form a vertically-stacked hybrid IC

Methodology Applied
Scientific EffectLayer transfer:

Data Source

PatentEP4134716B1Multi-layered hybrid integrated circuit assembly
Publication Date: 2025.10.29 INTEL CORP
  • EP4134716B1 patent drawingFigure 1
  • EP4134716B1 patent drawingFigure 2
  • EP4134716B1 patent drawingFigure 3

AI summary

Described herein are hybrid IC assemblies (100) that include multiple stacked layers of electronic and/or photonic circuit elements. For example, a first layer (110) of the IC assembly includes a waveguide formed of a substantially monocrystalline material, and a second layer (120) of the IC assembly includes at least one electronic circuit element. A bonding material (130) between a front face of the first layer (110) and a back face of the second layer (120) attaches the first layer (110) to the second layer (120). The bonding material has a lower crystallinity than the waveguide.