Semiconductor Light-Emitting Device Current-Blocking Layer Stability

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Solution Overview

Problem

The current-blocking layer in SDH-type semiconductor lasers experiences instability and increased current leakage due to impurity inter-diffusion between compound semiconductor layers, leading to thickness variations and reduced effectiveness.

Innovation Solution

A semiconductor light-emitting device is designed with a current-blocking layer composed of multiple compound semiconductor layers, where impurities are strategically placed at substitution sites to minimize inter-diffusion, using a laminated structure that includes specific impurities like Group III-V atoms and carbon or silicon to maintain layer integrity and prevent leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a current-blocking layer is formed by crystal growth from a recess surface in SDH-type semiconductor lasers, then the active layer can be completely covered and light confinement is improved, but impurity inter-diffusion occurs between compound semiconductor layers causing current leakage and reduced reliability

Engineering Contradiction:

Improvecurrent-blocking layer stabilityVSAvoidcurrent leakage

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The current-blocking layer is divided into multiple discrete compound semiconductor layers (first current-blocking layer, second current-blocking layer, etc.) with different impurity configurations. Each layer segment addresses specific impurity diffusion issues at different interfaces, preventing current leakage through distributed barrier functionality rather than a single homogeneous layer.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Compound semiconductor layers with specifically positioned impurities act as intermediary barrier layers between the active layer and surrounding structures. These intermediary layers with controlled impurity substitution sites prevent direct impurity inter-diffusion while maintaining the current-blocking function, resolving the contradiction between coverage and leakage prevention.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If impurities are added to compound semiconductor layers to control conductivity types, then current blocking function is enhanced, but impurity inter-diffusion increases causing thickness variations and reduced manufacturing precision

Engineering Contradiction:

Improvecurrent blocking effectivenessVSAvoidlayer thickness control

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

Impurities are strategically positioned at specific substitution sites within compound semiconductor layers rather than uniformly distributed. Different layers have different impurity configurations tailored to their specific interfaces and functions, achieving effective current blocking at critical locations while maintaining precise thickness control in other regions.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The impurity concentration, type, and substitution site are varied across different compound semiconductor layers to optimize both current blocking and thickness control. By changing impurity parameters locally rather than globally, the patent achieves effective current blocking where needed while maintaining manufacturing precision overall.

Inventive Principle:

Principle #35Parameter changes

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 configuration stabilizes the current-blocking layer, reducing current leakage and maintaining effective light confinement, even under high driving currents, by controlling impurity diffusion and maintaining layer thickness.

Implementation Method 1

impurity inter-diffusion between compound semiconductor layers

Methodology Applied

Scientific EffectImpurity diffusion: Diffusion

Implementation Method 2

impurities are strategically placed at substitution sites to minimize inter-diffusion

Methodology Applied

Scientific EffectSubstitution site blocking:

Implementation Method 3

maintaining effective light confinement

Methodology Applied

Scientific EffectLight confinement:

Data Source

PatentUS8320421B2Semiconductor light-emitting device

Publication Date: 2012.11.27 SONY GROUP CORP

AI summary

A semiconductor light-emitting device configured to decrease a leakage current in a current-blocking layer and including a light-emitting portion composed of a first compound semiconductor layer having a first conductivity type, an active layer, and a second layer having a second conductivity type, and a current-blocking layer in contact with the side of the light-emitting portion and composed of a third layer having the first conductivity type and a fourth layer having the second conductivity type.