Infrared LED Heterostructure for Flip-Chip Bonding and Heat Dissipation
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Solution Overview
Problem
Conventional ternary epitaxial structures for infrared LEDs are unsuitable for flip-chip packaging due to poor bonding between the p-type semiconductor layer and the SiO2 bonding layer, leading to peeling off of the epitaxial structure and inadequate heat dissipation and light-emitting efficiency.
Innovation Solution
The infrared LED features a semiconductor light-emitting unit with a quantum well active layer, waveguide layers, and cladding layers made of specific semiconductor compounds, forming a double heterojunction structure to enhance light-emitting efficiency and bonding, using (AlX3Ga1-X3)Y1In1-Y1P and (AlX4Ga1-X4)Y2In1-Y2P for the waveguide and cladding layers, respectively, and a sapphire substrate for improved mechanical support and light transmittance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional ternary epitaxial structure with p-type semiconductor layer is used for infrared LED, then the device can be manufactured with standard processes, but the bonding between the p-type semiconductor layer and SiO2 bonding layer is poor, causing the epitaxial structure to peel off during flip-chip packaging
Solution Approach 1:
The patent changes the material composition parameters of the semiconductor layers by introducing AlInP-based waveguide and cladding layers with specific aluminum and indium ratios, transforming the conventional AlGaAs ternary structure into a quaternary compound structure that provides both good bonding properties and desired optical characteristics
Solution Approach 2:
The patent employs a composite multi-layer structure combining AlInP-based waveguide layer, AlInP-based cladding layer, and GaAs-based active layer, creating a composite material system that integrates the advantages of different semiconductor compounds to achieve both reliable bonding and efficient light emission
2Temperature
If flip-chip packaging is applied to conventional infrared LED, then heat dissipation and packaging reliability should be enhanced, but the poor bonding causes the epitaxial structure to fail and prevents successful flip-chip packaging
Solution Approach 1:
The patent modifies the material parameters by using AlInP-based layers with optimized composition ratios, changing the thermal and bonding properties of the semiconductor structure to enable both effective heat dissipation and strong bonding required for flip-chip packaging
3Device complexity
If conventional ternary epitaxial structure is used, then the device structure is simple, but the light-emitting efficiency is insufficient and the forward voltage is high
Solution Approach 1:
The patent uses composite AlInP-based waveguide and cladding layers combined with GaAs active layer to create a multi-functional structure that simultaneously improves light-emitting efficiency, reduces forward voltage, and maintains reasonable structural complexity
Solution Approach 2:
The patent applies different material compositions to different layers: AlInP-based materials for waveguide and cladding layers to optimize optical confinement and bonding, while using GaAs for the active layer to maximize light emission efficiency, creating local optimization throughout the structure
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 the light-emitting efficiency, reduces lattice mismatch, and enhances bonding between the epitaxial structure and the substrate, resulting in higher power output and lower forward voltage, addressing the limitations of conventional infrared LED packaging.
Implementation Method 1
The active layer has a quantum well structure which includes at least one pair of layers, each pair of layers including a well layer and a barrier layer
Implementation Method 2
The first waveguide layer and the second waveguide layer are respectively disposed on two opposite sides of the active layer
Data Source
AI summary
An infrared light-emitting diode (LED) includes a semiconductor light-emitting unit which includes an active layer, a first waveguide layer, a second waveguide layer, a first cladding layer and a second cladding layer. The active layer includes at least one pair of layers. Each pair of layers includes a well layer and a barrier layer. The first and the second waveguide layers are respectively disposed on two opposite sides of the active layer, and are independently made of a semiconductor compound represented by (AlX3Ga1-X3)Y1In1-Y1P, wherein 0≤X3≤1 and 0≤Y1≤1. The first cladding layer is disposed on the first waveguide layer opposite to the active layer. The second cladding layer is disposed on the second waveguide layer opposite to the active layer.