Back-Side Illuminated Sensor Direct Bonding Logic

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Solution Overview

Problem

Existing solid-state image capturing devices face challenges in achieving a small form factor while maintaining cost-effectiveness, particularly in back-side illuminated configurations where the integration of peripheral circuits with the sensor semiconductor element is complex due to the need for support substrates and precise via formation.

Innovation Solution

A back-side illuminated solid-state image capturing device design that incorporates a combination of penetration vias and land electrodes with distinct pitch diameters, along with a rewiring configuration, to enhance area efficiency and reduce the size of the sensor semiconductor element, allowing for simpler manufacturing and integration of logic semiconductor elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a back-side illuminated sensor semiconductor element is used with peripheral circuit integration, then photoelectric conversion efficiency is improved, but device complexity and manufacturing difficulty increase due to support substrate requirements

Engineering Contradiction:
Improvephotoelectric conversion efficiencyVSAvoidintegration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the support substrate from the integration structure, allowing the sensor semiconductor element to be mounted directly on the logic semiconductor element. This eliminates the intermediate support substrate layer while maintaining mechanical strength through direct bonding, thereby reducing device complexity without compromising photoelectric conversion efficiency

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of mounting the sensor semiconductor element on a support substrate and then integrating the logic circuit, the patent inverts the structure by directly mounting the sensor element on the logic semiconductor element. This inversion simplifies the overall device architecture and reduces manufacturing steps

Inventive Principle:
Principle #13The other way round (Inversion)

2Manufacturing precision

If penetration vias with small pitch are formed in support substrate, then connection precision is improved, but manufacturing difficulty increases

Engineering Contradiction:
Improvevia formation precisionVSAvoidmanufacturing difficulty
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent removes the support substrate from the structure, eliminating the need to form penetration vias through it. The connection is established directly between the sensor semiconductor element and logic semiconductor element through bonding pads, thereby achieving precise connections without the manufacturing complexity of small-pitch via formation in thick substrates

Inventive Principle:
Principle #2Taking out (Extraction)

3Area of stationary object

If sensor semiconductor element size is reduced for smaller device, then area efficiency is improved, but structural strength decreases

Engineering Contradiction:
Improvesensor element areaVSAvoidstructural strength
Core Design Contradiction:
Area of stationary objectVSStrength

Solution Approach 1:

The patent merges the sensor semiconductor element directly with the logic semiconductor element through direct bonding, creating a unified structure. This integration provides mechanical support through the combined structure, allowing the sensor element to be miniaturized without compromising overall structural strength

Inventive Principle:
Principle #5Merging (Combining)

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 production of a smaller solid-state image capturing device with improved area efficiency, facilitating the integration of logic semiconductor elements while maintaining the necessary strength and reducing manufacturing complexity.

Implementation Method 1

a photoelectric conversion element that photoelectrically converts incident light

Methodology Applied
Scientific EffectPhotoelectric conversion: Photoelectric Effect

Data Source

PatentEP3268990B1Imaging device, manufacturing method, and electronic device
Publication Date: 2022.12.21 SONY GROUP CORP
  • EP3268990B1 patent drawingFigure 1
  • EP3268990B1 patent drawingFigure 2
  • EP3268990B1 patent drawingFigure 3

AI summary

There is provided an imaging device including: a first semiconductor substrate (21) having a first region (22, R11) that includes a photoelectric conversion section (67) and a via portion (51), a second region (R12) adjacent to the first region, a connection portion (53, 84, 85) disposed at the second region, and a second semiconductor substrate (81), wherein the connection portion electrically couples the first semiconductor substrate to the second semiconductor substrate in a stacked configuration, and wherein a width of the connection portion is greater than a width of the via portion.