Semiconductor Light-Emitting Element Cleaving for Perpendicular End Faces

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Solution Overview

Problem

Existing semiconductor light-emitting elements face issues with end surface perpendicularity, leading to variations in threshold current and slope efficiency due to non-perpendicular end surfaces, which result in guided wave loss and characteristic deterioration.

Innovation Solution

A semiconductor light-emitting element with a stacking structure featuring a first depression on the edge adjacent to the second surface and a second depression extending along the thickness direction, facilitating perpendicular end surface formation through controlled cleaving and stress concentration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If scribing and cleaving are performed after crystal-growing a semiconductor layer on a substrate, then the semiconductor laser can be manufactured, but the end surfaces may not be formed perpendicularly, causing variation in threshold current and reducing reflectance

Engineering Contradiction:
Improvemanufacturing processVSAvoidend surface perpendicularity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent forms guide grooves on the substrate surface before crystal-growing the semiconductor layer. These pre-formed guide grooves serve as templates that direct the cleavage process, ensuring that end surfaces are formed perpendicularly to the substrate. This preliminary action prevents the perpendicularity problem that occurs when scribing and cleaving are performed after crystal-growing.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces guide grooves that extend in the thickness direction of the stacking structure, creating a three-dimensional feature on the substrate surface. This vertical dimension of the guide grooves provides mechanical guidance during cleavage, ensuring that the cleavage front propagates perpendicular to the substrate surface, thereby solving the perpendicularity issue.

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

2Ease of manufacture

If end surfaces are not formed perpendicularly, then manufacturing is simpler, but guided wave loss occurs and characteristics such as threshold current and slope efficiency deteriorate

Engineering Contradiction:
Improveend surface formationVSAvoidlaser characteristics
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

By forming guide grooves before crystal-growing, the patent establishes a geometric constraint that ensures perpendicular end surface formation during cleavage. This preliminary structural preparation maintains laser characteristics such as threshold current and slope efficiency without complicating the manufacturing process.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If guide grooves are formed to ensure perpendicular end surfaces, then manufacturing precision is improved, but device complexity increases

Engineering Contradiction:
Improveend surface perpendicularityVSAvoidstacking structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent segments the substrate surface by forming guide grooves that divide the substrate into regions. These grooves create discrete cleavage paths that ensure perpendicular end surfaces without requiring complex overall structural changes. The segmentation is localized to the groove formation, keeping device complexity minimal.

Inventive Principle:
Principle #1Segmentation

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

The solution secures perpendicularity of end surfaces, suppresses characteristic deterioration, and enhances flatness and reflectance, improving threshold current and slope efficiency while reducing guided wave loss.

Implementation Method 1

a second depression formed on a second edge extending along a thickness direction of the stacking structure, wherein the second depression is provided as a hole continuously formed from the first surface to the second surface of the stacking structure

Methodology Applied
Scientific EffectStress concentration:

Data Source

PatentEP3493338B1Semiconductor light-emitting element and method for manufacturing semiconductor light-emitting element
Publication Date: 2024.09.04 SONY SEMICON SOLUTIONS CORP
  • EP3493338B1 patent drawingFigure 1
  • EP3493338B1 patent drawingFigure 2~4
  • EP3493338B1 patent drawingFigure 5

AI summary

The semiconductor light-emitting element includes: a stacking structure having a substrate and a semiconductor layer between a first surface and a second surface that face each other in order from a side on which the first surface is located, the substrate including a compound semiconductor, and the semiconductor layer being crystal-grown on the substrate and including a light-emitting region; a first depression formed on at least a portion of a first edge adjacent to the second surface of the stacking structure; and a second depression formed on a second edge extending along a thickness direction of the stacking structure.