Semiconductor Light Emission Element Junction Layer
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Solution Overview
Problem
The use of Cr in junction layers of semiconductor light emission elements can lead to the ingress of air or moisture, causing decomposition and reducing the lifespan of the device due to its high bonding properties with nitride semiconductors and transparent electrodes.
Innovation Solution
A semiconductor light emission element with a junction layer comprising valve action metals like Al, Ti, Zn, Zr, Nb, W, Mg, Bi, Si, Hf, or Ta, where the junction layer is in contact with the transparent electrode, and a connection electrode with a bonding layer of Au or Al, optionally including a barrier layer, to enhance bonding and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If Cr is used as a component of the junction layer to improve bonding property with transparent electrode and semiconductor layer, then bonding property is improved, but air or moisture enters the junction layer causing decomposition and shortening device life
Solution Approach 1:
The patent removes Cr from the junction layer composition to eliminate the harmful effect of Cr that allows air and moisture penetration. The junction layer is formed using alternative materials (Al, Ti, Zn, Zr, Nb, W, Mg, Bi, Si, Hf, or Ta) that do not exhibit the same detrimental properties, thereby extracting the problematic element while maintaining the bonding function through other means.
Solution Approach 2:
The patent employs composite material structures in the electrode assembly, combining transparent electrode material with junction layer materials (Al, Ti, Zn, Zr, Nb, W, Mg, Bi, Si, Hf, or Ta) and connection electrode materials (Au, Al) to achieve both strong bonding and protection against air and moisture ingress. This composite approach allows optimization of each layer's properties to collectively solve the contradiction.
2Strength
If Cr is used in the junction layer to enhance bonding with transparent electrode, then bonding strength increases, but the junction layer becomes susceptible to air and moisture decomposition
Solution Approach 1:
The patent extracts Cr from the junction layer to eliminate the specific harmful property of Cr that enables air and moisture penetration. By removing this element entirely and substituting it with alternative materials, the patent prevents the harmful effect while maintaining bonding functionality through the combined structure of transparent electrode + junction layer + connection electrode.
Solution Approach 2:
The patent changes the material composition parameter of the junction layer from Cr-based to alternative metal-based materials (Al, Ti, Zn, Zr, Nb, W, Mg, Bi, Si, Hf, or Ta). This parameter change fundamentally alters the chemical properties of the junction layer, making it resistant to air and moisture decomposition while maintaining adequate bonding strength through the layered structure.
Data Source
AI summary
A semiconductor light emission element (1) includes: a substrate (110); multi-layered semiconductor layers (100) including a light emission layer (150) and layered on the substrate (110); a transparent electrode (170) including an indium oxide and layered on the multi-layered semiconductor layers (100); a first junction layer (190) including tantalum as a valve action metal and layered on the transparent electrode (170) in such a manner that a side of the first junction layer (190) being in contact with the transparent electrode (170) is a tantalum nitride layer or a tantalum oxide layer; and a first bonding pad electrode (200) layered on the first junction layer (190) and used for electrical connection with outside. This improves a bonding property of the transparent electrode or the semiconductor layer with the connection electrode and reliability of the electrodes.