Nitride Semiconductor Laser Electrode Space Prevents Hydrogen Diffusion

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Solution Overview

Problem

Conventional nitride semiconductor lasers experience an increase in operating voltage over time due to hydrogen diffusion from the SiO2 dielectric layer to the electrode components.

Innovation Solution

Incorporating a space between the electrode component and the dielectric layer, which includes SiO2, to prevent contact and thus hinder hydrogen diffusion, while ensuring the electrode component is in contact with the upper surface of the ridge portion, and using a pad electrode that is wider than the ridge portion for improved electrical connection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the dielectric layer including SiO2 is placed in contact with the electrode component, then the manufacturing process is simplified, but hydrogen diffuses to the electrode component causing operating voltage to increase

Engineering Contradiction:

Improvemanufacturing process simplicityVSAvoidoperating voltage stability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The structure is segmented by introducing a space between the dielectric layer and electrode component, separating them to prevent harmful hydrogen diffusion while maintaining manufacturing feasibility through controlled spacing

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A space is introduced as an intermediary element between the dielectric layer and electrode component, acting as a barrier to hydrogen diffusion while allowing both components to maintain their respective functions without direct contact

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the electrode component is made wider than the ridge portion, then electrical connection is improved, but the electrode component may contact the dielectric layer causing hydrogen diffusion

Engineering Contradiction:

Improveelectrical connection qualityVSAvoidhydrogen diffusion to electrode

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The problem is resolved by transitioning from a two-dimensional contact problem to a three-dimensional spatial arrangement, where the space vertically separates the electrode component from the dielectric layer while allowing horizontal width expansion for better electrical connection

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 configuration reduces the increase in operating voltage over time, enhances the reliability of the nitride semiconductor laser, and allows for high light output operation by maintaining good ohmic contact and reducing peeling-off issues.

Implementation Method 1

diffusion of hydrogen contained in the dielectric layer including SiO 2 to the electrode component

Methodology Applied

Scientific EffectHydrogen diffusion: Diffusion

Data Source

PatentEP3487016B1Nitride semiconductor laser and nitride semiconductor laser device

Publication Date: 2021.09.22 PANASONIC HOLDINGS CORP

Figure 1(a)~1(b)
Figure 2A~2C
Figure 2D~2F

AI summary

A nitride semiconductor laser (1) includes: a first nitride semiconductor layer (20); a light-emitting layer (30) formed on the first nitride semiconductor layer (20) and including a nitride semiconductor; a second nitride semiconductor layer (40) formed on the light-emitting layer (30) and having a ridge portion (40a); an electrode component (50) formed on the second nitride semiconductor layer (40), and which is wider than the ridge portion (40a); and a dielectric layer (60) formed on side surfaces of the ridge portion (40a) and including SiO2. A space (70) is present between the electrode component (50) and the dielectric layer (60), and the electrode component (50) is prevented from being in contact with the dielectric layer (60) by the space (70), and is in contact with the upper surface of the ridge portion (40a).