LED Epitaxy Adhesive Conductive Layer for Silver Migration
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Solution Overview
Problem
Conventional light emitting diodes (LEDs) face issues with silver migration and poor adhesion between the reflective layer and the epitaxy structure, leading to electrical leakage and layer peeling, which affects performance and reliability.
Innovation Solution
A method involving the formation of an LED epitaxy structure on a substrate, followed by etching and filling with a transparent dielectric material, and then forming an ohmic contact and reflective layer, with an adhesive conductive complex layer to secure these layers on the epitaxy structure, enhancing adhesion and preventing peeling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If silver is used as the reflective layer material, then the reflective index is improved, but silver migration occurs causing electrical leakage
Solution Approach 1:
An adhesive conductive complex layer is introduced as an intermediary between the silver reflective layer and the LED epitaxy structure. This intermediate layer prevents direct contact between silver and the semiconductor layers, thereby blocking silver migration that causes electrical leakage, while still allowing the reflective layer to perform its light-reflecting function effectively.
2Illumination intensity
If silver is used as the reflective layer, then the brightness is improved, but adhesion between layers deteriorates causing peeling
Solution Approach 1:
The adhesive conductive complex layer serves as a mediator that provides strong adhesion between the silver reflective layer and the LED epitaxy structure. This intermediate layer has been specifically designed to bond well with both the metal reflective layer and the semiconductor structure, preventing peeling while maintaining the optical performance of the silver layer.
Solution Approach 2:
The adhesive conductive complex layer is a composite material structure that combines adhesive properties with conductive properties. This composite structure provides both mechanical bonding strength to prevent peeling and electrical conductivity to maintain device functionality, while also serving as a barrier against silver migration.
3Ease of manufacture
If conventional lift-off step is performed, then substrate removal is achieved, but cracks occur between layers due to temperature variation
Solution Approach 1:
The adhesive conductive complex layer is formed beforehand as a cushioning layer that compensates for thermal stress during the lift-off process. This intermediate layer has mechanical properties that accommodate temperature variations and stress changes, preventing crack formation between the reflective layer and the LED epitaxy structure during substrate removal.
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 adhesion between the reflective layer and the epitaxy structure, reducing electrical leakage and peeling, thereby enhancing the LED's performance and reliability by ensuring that the layers remain securely attached during the fabrication and operation of the LED.
Implementation Method 1
improve the adhesion between the reflective layer and the LED epitaxy structure
Implementation Method 2
The ohmic contact layer and the reflective layer are fixed on the LED epitaxy structure by good adhesion between the adhesive conductive complex layer and the transparent dielectric material
Data Source
AI summary
A light emitting diode and the method of the same are provided. A light emitting diode epitaxy structure is formed on a substrate, and then the light emitting diode epitaxy structure is etched to form a recess. The recess is then filled with a transparent dielectric material. An ohmic contact layer and a reflective layer are formed sequentially, and then are etched to expose the transparent dielectric material. Finally, forming an adhesive conductive complex layer to fix the ohmic contact layer and the reflective layer on the light emitting diode epitaxy structure.