Nitride Semiconductor Light-Emitting Device With Compressive Stress Layers
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Solution Overview
Problem
Semiconductor light-emitting devices fabricated using nitride semiconductors on silicon substrates face issues with tensile stress, leading to cracks and defects, which can cause fabrication failures and degrade device characteristics, especially when the silicon substrate is less expensive but less efficient in manufacturing compared to sapphire substrates.
Innovation Solution
Incorporating a first and second stress application layer with compressive stress to counteract the tensile stress in the nitride semiconductor layers, using AlN and AlGaN layers to apply compressive stress to the semiconductor crystal layers, thereby reducing the likelihood of cracks and defects during the fabrication process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a semiconductor light-emitting device is formed by epitaxial growth of a nitride semiconductor crystal on a silicon substrate, then cost is reduced and manufacturing efficiency is improved, but tensile stress causes cracks and defects leading to fabrication failure and deteriorated device characteristics
Solution Approach 1:
The patent applies preliminary anti-action by introducing a stress application layer that exerts compressive stress on the nitride semiconductor crystal layer before the tensile stress can cause cracks or defects. This pre-applied compressive stress counteracts the inherent tensile stress during the epitaxial growth process on silicon substrate, preventing fabrication failures and maintaining device characteristics while enabling cost-effective manufacturing.
2Ease of manufacture
If a semiconductor light-emitting device is formed by epitaxial growth of a nitride semiconductor crystal on a silicon substrate, then cost is reduced, but tensile stress causes cracks and defects
Solution Approach 1:
The stress application layer is introduced to apply compressive stress in advance to counteract the tensile stress that would otherwise cause cracks and defects during epitaxial growth on cost-effective silicon substrates
Solution Approach 2:
The patent converts the harmful tensile stress into a beneficial compressive stress state by using the stress application layer to apply controlled compression, thereby transforming the potential source of cracks and defects into a protective mechanism that enhances crystal layer integrity while maintaining cost advantages of silicon substrate manufacturing.
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 implementation of compressive stress application layers effectively suppresses the occurrence of cracks and defects, enhancing the light-emitting efficiency and maintaining high device characteristics even when using less expensive silicon substrates.
Implementation Method 1
a first stress application layer provided on a side opposite to the light emitting layer of the first semiconductor layer and applying a compressive stress to the first semiconductor layer
Data Source
AI summary
According to one embodiment, a semiconductor light-emitting device includes: a first conductivity type first semiconductor layer containing a nitride semiconductor crystal and having a tensile stress in a (0001) surface; a second conductivity type second semiconductor layer containing a nitride semiconductor crystal and having a tensile stress in the (0001) surface; a light emitting layer provided between the first semiconductor layer and the second semiconductor layer, containing a nitride semiconductor crystal, and having an average lattice constant larger than the lattice constant of the first semiconductor layer; and a first stress application layer provided on a side opposite to the light emitting layer of the first semiconductor layer and applying a compressive stress to the first semiconductor layer.