Semiconductor Light-Emitting Device Electrode Stack for Adhesion
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Solution Overview
Problem
Semiconductor light-emitting devices face challenges in improving light extraction efficiency and reliability due to issues with adhesive force between metal and oxide layers, and electrical characteristics, particularly in high-humidity environments and high-current modes.
Innovation Solution
The semiconductor light-emitting device incorporates a channel layer of transparent material, a current blocking layer, an ohmic layer, and an electrode layer with a stack structure including an ohmic contact layer, barrier layers, and a conductive layer to enhance light reflection and adhesive force, while preventing electrical shorts and exfoliation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a metal electrode layer is directly formed on the semiconductor layer, then electrical contact is achieved, but adhesive force is insufficient and electrical characteristics deteriorate in high-humidity environments
Solution Approach 1:
The electrode structure is divided into multiple functional layers: a lower electrode layer for adhesion and electrical contact, and an upper electrode layer for current conduction. This segmentation allows each layer to optimize its specific function, improving overall reliability without excessive complexity.
Solution Approach 2:
An intermediary layer is introduced between the metal electrode and the semiconductor layer to enhance adhesive force and prevent electrical shorts. This intermediary layer acts as a mediator that improves the interface properties between dissimilar materials.
2Productivity
If current density is increased to improve light extraction efficiency, then operational performance improves, but electrical shorts and exfoliation occur
Solution Approach 1:
The electrode structure uses composite material layers with different properties: a lower layer material optimized for adhesion to the semiconductor, and an upper layer material optimized for current conduction. This composite structure allows high current density operation without electrical shorts or exfoliation.
3Use of energy by moving object
If operational voltage is reduced to improve efficiency, then energy consumption decreases, but contact resistance increases
Solution Approach 1:
The lower electrode layer is designed in advance to provide excellent adhesion and low contact resistance at the semiconductor interface. This preliminary action ensures low contact resistance before the upper current-conducting layer is added, enabling reduced operational voltage without sacrificing electrical contact quality.
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 improves light extraction efficiency, increases chip reliability, and provides stable operation with low operation voltage, even in high-current modes, by reducing contact resistance and enhancing adhesive forces between layers.
Implementation Method 1
a channel layer of transparent material... to enhance light reflection
Implementation Method 2
an ohmic layer, and an electrode layer with a stack structure including an ohmic contact layer... reducing contact resistance
Data Source
AI summary
A semiconductor light-emitting device is provided that may include an electrode layer, a light-emitting structure including a compound semiconductor layer on the electrode layer, and an electrode on the light-emitting structure, wherein the electrode includes an ohmic contact layer that contacts the compound semiconductor layer, a first barrier layer on the ohmic contact layer, a conductive layer including copper on the first barrier layer, a second barrier layer on the conductive layer, and a bonding layer on the second barrier layer.