Image Sensor Reinforcement Layer for Lens Adhesion

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Solution Overview

Problem

Image sensing devices face issues with the lens capping layer being easily peeled off, leading to flare phenomena and potential damage to the light shielding layer during the etching process for patterning, which affects the performance and reliability of the device.

Innovation Solution

The implementation of a reinforced structure with a structural reinforcement layer, including a plurality of fingers with rounded upper ends and lateral extensions, which are consecutively arranged to form an annular shape surrounding the microlenses and light shielding layer, prevents the lens capping layer from being peeled off and protects the light shielding layer from damage during the etching process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a lens capping layer is formed over microlenses, then the microlenses are protected and optical performance is improved, but the lens capping layer is easily peeled off causing flare phenomena

Engineering Contradiction:

Improveadhesion of lens capping layerVSAvoidflare phenomenon

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The reinforcement structure is divided into multiple fingers that are consecutively arranged and connected to each other, forming an annular shape. This segmented structure provides effective adhesion support while allowing the lens capping layer to be properly attached, preventing peeling and flare phenomena.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The reinforcement structure acts as an intermediary between the lens capping layer and the underlying layers. It provides mechanical support and adhesion enhancement, serving as a mediator that prevents the lens capping layer from peeling off while protecting the microlenses underneath.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Manufacturing precision

If etching process is performed for patterning the lens capping layer, then the lens capping layer is precisely patterned, but the light shielding layer at the lower portion is damaged

Engineering Contradiction:

Improvepatterning precision of lens capping layerVSAvoidintegrity of light shielding layer

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The reinforcement structure is formed in advance before the etching process. This preliminary structure provides protective support to the light shielding layer during the subsequent etching process, preventing damage while allowing precise patterning of the lens capping layer to proceed.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The reinforcement structure serves as a cushioning layer formed beforehand to protect the light shielding layer during the etching process. It absorbs or distributes the mechanical stress and chemical effects of etching, preventing damage to the underlying light shielding layer while enabling precise patterning.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Device complexity

If the lens capping layer is made thin to reduce complexity, then device complexity is reduced, but the layer becomes easily peeled off

Engineering Contradiction:

Improvestructure complexityVSAvoidpeel resistance of lens capping layer

Core Design Contradiction:

Device complexityVSStrength

Solution Approach 1:

Instead of simply increasing the thickness of the lens capping layer, the reinforcement structure extends in a different dimension - forming an annular shape with fingers that provide lateral support and adhesion enhancement. This dimensional approach strengthens the structure without increasing vertical complexity.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 design effectively prevents the lens capping layer from being easily peeled off, thereby eliminating the flare phenomenon and ensuring the structural integrity of the light shielding layer, even during the etching process, enhancing the overall performance and reliability of the image sensing device.

Implementation Method 1

a plurality of microlenses disposed over the planarization layer to converge incident light onto the sensor pixels

Methodology Applied

Scientific EffectLight convergence: Lens

Implementation Method 2

a structural reinforcement layer disposed over the planarization layer to surround the microlenses... to prevent damage to a light shielding layer located at a lower portion of a lens layer

Methodology Applied

Scientific EffectMechanical reinforcement: Mechanical Force

Data Source

PatentUS11610926B2Image sensing device with structural reinforcement layer

Publication Date: 2023.03.21 SK HYNIX INC

AI summary

An image sensing device that includes a reinforced structure is disclosed. The image sensing device includes a semiconductor substrate structured to include a pixel region including a plurality of unit pixels and a peripheral region located outside the pixel region, a plurality of microlenses disposed over the semiconductor substrate in the pixel region, a structural reinforcement layer disposed over the semiconductor substrate in the peripheral region, and a lens capping layer structured to cover the microlenses and at least of the structural reinforcement layer. The structural reinforcement layer includes a plurality of fingers each finger vertically structured to have a rounded upper end and laterally extend to have a predetermined length toward the pixel region. The fingers are consecutively arranged and connected to each other in a lateral direction, and side surfaces of fingers are in contact with side surfaces of immediately adjacent fingers.