Semiconductor Laser Element Bulk Defect Suppression

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Solution Overview

Problem

Semiconductor laser devices experience characteristic deterioration due to defects generated not only at the edge but also in the bulk of the semiconductor crystal, particularly under high output conditions, leading to dislocation loops in the active layer or its vicinity.

Innovation Solution

Incorporating a III-V group semiconductor crystal with As as a primary component, where a V group element like P is introduced at a concentration of 0.02 to 5% into the well and barrier layers, and In at 0.1 to 1% into the III group site, along with n-type doping, to stabilize As interstitial atoms and prevent cluster formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the output power of the semiconductor laser device is increased to several tens of watts or more, then the power output is improved, but dislocation loops are generated and grown in the bulk of the active layer, causing characteristic deterioration

Engineering Contradiction:
Improveoutput powerVSAvoidcharacteristic stability
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The patent applies local quality by introducing specific impurity elements (Si, Ge, C) at controlled concentrations (10^16 to 10^18 atoms/cm³) into specific regions of the semiconductor crystal structure, particularly into the active layer and surrounding layers. This creates localized modifications in the crystal lattice that prevent dislocation loop formation without affecting the overall high power output capability of the device.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the chemical composition parameters of the semiconductor crystal by introducing impurity elements with different atomic sizes and bonding characteristics. These parameter changes (adding Si, Ge, or C atoms) modify the crystal lattice properties to suppress dislocation generation and growth, enabling the device to maintain reliability at high power levels.

Inventive Principle:
Principle #35Parameter changes

2Power

If the breakdown voltage is increased to achieve higher output, then the power output is improved, but defects are generated in the bulk of the semiconductor crystal, leading to characteristic deterioration

Engineering Contradiction:
Improvepower outputVSAvoidcrystal quality
Core Design Contradiction:
PowerVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by introducing impurity elements during the crystal growth process itself, before the device is put into operation. The impurities are incorporated into the crystal lattice during epitaxial growth, pre-establishing a structure that resists dislocation formation under subsequent high voltage and high power operating conditions.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The impurity elements (Si, Ge, C) act as intermediaries that modify the crystal growth process and lattice structure. These intermediary atoms facilitate the incorporation of energy and stress distribution that prevents dislocation loop formation, mediating between the high breakdown voltage requirements and the need for high crystal quality.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the concentration of impurity elements is increased to suppress dislocation loops, then the reliability is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improvedefect suppressionVSAvoidmanufacturing process
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent employs composite materials by creating a multi-layer semiconductor structure with different compositions. The active layer contains the impurity elements at specific concentrations, while surrounding layers have different compositions, forming a composite structure that suppresses dislocation loops. This composite approach integrates reliability improvement into the material design itself.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the concentration parameter of impurity elements within a specific range (10^16 to 10^18 atoms/cm³) to achieve optimal defect suppression. By precisely controlling this parameter during manufacturing, the patent balances reliability improvement with manufacturing feasibility, avoiding the need for excessively complex processing while achieving the desired defect suppression.

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 approach effectively suppresses the generation of dislocation loops in the bulk semiconductor crystal, reducing variation in characteristics and improving the semiconductor laser device's performance by stabilizing As interstitial atoms and preventing cluster formation.

Implementation Method 1

a V group element other than As has been introduced at a concentration of 0.02 to 5% into a V group site of the III-V group semiconductor crystal... to stabilize As interstitial atoms and prevent cluster formation

Methodology Applied
Scientific EffectInterstitial atom stabilization:

Data Source

PatentEP3118950B1Semiconductor laser element
Publication Date: 2020.09.09 FURUKAWA ELECTRIC CO LTD
  • EP3118950B1 patent drawingFigure 1~2
  • EP3118950B1 patent drawingFigure 3
  • EP3118950B1 patent drawingFigure 4

AI summary

A semiconductor laser device includes a well layer and a barrier layer formed of a III-V group semiconductor crystal containing As as a primary component. A V group element other than As has been introduced at a concentration of 0.02 to 5% into a V group site of the III-V group semiconductor crystal in at least one of the well layer and the barrier layer. A III group site of the III-V group semiconductor crystal in at least one of the well layer and the barrier layer contains Al. A semiconductor laser device suppressing generation of defects in a bulk of a semiconductor crystal and having less variation of characteristics is thereby provided.