GaN Light-Emitting Element Electrode Structure for Enhanced Light Extraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Semiconductor light-emitting elements using GaN-based compound semiconductors face challenges with p-type electrode transparency, light extraction, and anticorrosion properties, leading to inefficient light emission and poor manufacturing yields due to weak bonding pad electrodes and insufficient anticorrosion resistance.
Innovation Solution
A semiconductor light-emitting element design featuring a junction layer and a bonding pad electrode with a maximum thickness greater than the junction layer, incorporating metal reflection layers and transparent conductive materials, and a manufacturing method that includes forming a reverse-tapered mask and sputtering techniques to enhance junction and anticorrosion properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a transparent electrode made of metal oxide such as ITO or a metal thin film is used, then light extraction is improved, but electrode strength is insufficient
Solution Approach 1:
The patent applies composite materials by combining a transparent conductive oxide layer (ITO) with a metal reflection layer (Al, Ag, or Ti) and a bonding pad electrode layer (Au or Al). This multi-layer composite structure provides both the transparency needed for light extraction and the mechanical strength required for bonding, resolving the contradiction between light extraction performance and electrode strength.
2Strength
If a bonding pad electrode with specified thickness is arranged on the transparent electrode, then electrode strength is improved, but light extraction is blocked
Solution Approach 1:
The patent applies local quality by creating a multi-layer structure where different materials are positioned at specific locations: the transparent conductive oxide layer maintains transparency in regions requiring light extraction, while the metal reflection layer and bonding pad electrode are positioned locally to provide strength where needed. The bonding pad electrode is configured with specific thickness and positioning to balance mechanical strength and optical transparency.
3Illumination intensity
If a metal reflection layer is used to reflect emitted light, then light extraction from other portions is improved, but bonding pad electrode strength remains insufficient
Solution Approach 1:
The patent combines the metal reflection layer (Al, Ag, or Ti) with the bonding pad electrode layer (Au or Al) in a composite multi-layer structure. This composite design allows the metal reflection layer to perform its light reflection function while the bonding pad electrode layer provides the necessary mechanical strength for bonding, simultaneously achieving both light extraction enhancement and electrode strength.
4Ease of manufacture
If the electrode structure is simplified, then manufacturing is easier, but junction and anticorrosion properties are insufficient
Solution Approach 1:
The patent employs a systematic multi-layer composite structure consisting of the transparent conductive oxide layer, metal reflection layer, and bonding pad electrode layer. This composite design, while multi-component, follows a standardized manufacturing process using sputtering techniques, achieving both reliable junction and anticorrosion properties through the synergistic combination of materials while maintaining manufacturing feasibility.
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 solution improves the junction and anticorrosion properties of the semiconductor light-emitting element, preventing air and moisture penetration, enhancing light extraction, and increasing the element's lifespan and manufacturing yield.
Implementation Method 1
a manufacturing method that includes forming a reverse-tapered mask and sputtering techniques to enhance junction and anticorrosion properties
Data Source
AI summary
A semiconductor light-emitting element including a substrate, a laminated semiconductor layer including a light-emitting layer formed over the substrate, one electrode (111) formed over the upper face of the laminated semiconductor layer, and an other electrode formed over the exposed surface of the semiconductor layer, from which the laminated semiconductor layer is partially cut off. The one electrode (111) includes a junction layer (110) and a bonding pad electrode (120) formed to cover the junction layer. The bonding pad electrode has a maximum thickness larger than that of the junction layer, and is composed of one or two or more layers. Slopes (110c), (117c) and (119c), which are made gradually thinner toward the outer circumference, are formed in the outer circumference portions (110d) and (120d) of the junction layer and the bonding pad electrode. Also disclosed is a method for manufacturing the element and a lamp.