InxGa1-xN Strain Relief Layer for Semiconductor Light Emitting Device
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Solution Overview
Problem
Conventional semiconductor light emitting devices face challenges in achieving effective strain relief and maintaining a simple structure, which affects the epitaxial quality and light emission efficiency of the light emitting layer.
Innovation Solution
A semiconductor light emitting device with a strain relief layer made of InxGa1-xN, where 0<x<1, is introduced between the N-type semiconductor layer and the multiple quantum well light emitting layer, with a thickness 10 to 100 times that of the well layer, and an indium content lower than the well layers, to provide a single layer structure for strain relief and improved production yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a super lattice structure strain relief layer is employed between the N-type semiconductor layer and the light emitting layer, then strain relief effect is achieved, but device structure becomes complex
Solution Approach 1:
The strain relief layer is segmented into multiple sub-layers with different indium contents (first strain relief sub-layer with lower indium content, second strain relief sub-layer with higher indium content). This segmentation allows each sub-layer to handle different aspects of strain relief, achieving effective strain management while maintaining structural simplicity compared to traditional super lattice structures.
Solution Approach 2:
The patent changes the indium content parameter across different strain relief sub-layers, creating a gradient structure where the first sub-layer has lower indium content and the second sub-layer has higher indium content. This parameter variation enables optimized strain relief at different depths without requiring complex super lattice patterns.
2Reliability
If high indium content is used in the strain relief layer to improve strain relief, then strain relief effectiveness increases, but internal stress and crystal defects increase
Solution Approach 1:
Different regions of the strain relief layer are assigned different indium contents based on their specific needs. The first strain relief sub-layer adjacent to the N-type semiconductor layer uses lower indium content to minimize defects near the interface, while the second strain relief sub-layer uses higher indium content to provide enhanced strain relief further from the interface. This local optimization resolves the contradiction between strain relief effectiveness and defect reduction.
Solution Approach 2:
The strain relief layer is positioned and designed in advance before the light emitting layer is grown. By pre-establishing the strain relief structure with optimized indium content distribution, the patent prevents strain accumulation that would otherwise lead to defects in subsequent layers, acting as a preliminary protective measure.
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 enhances the epitaxial quality and light emission efficiency by effectively releasing strain and maintaining a simple device structure, while avoiding excessive indium content that could lead to internal stress and crystal defects.
Implementation Method 1
a strain relief layer is introduced between the N-type semiconductor layer and the multiple quantum well light emitting layer
Implementation Method 2
made of InxGa1-xN, wherein 0<x<1, and an indium content lower than the well layers
Data Source
AI summary
A semiconductor light emitting device including an N-type semiconductor layer, a P-type semiconductor layer, a light emitting layer and a strain relief layer is provided. The light emitting layer is disposed between the N-type semiconductor layer and the P-type semiconductor layer, and the light emitting layer is a multiple quantum well structure. The strain relief layer is disposed between the light emitting layer and the N-type semiconductor layer, and is made of InxGa1-xN, where 0<x<1. The difference between any two values of x corresponded to any two positions in the strain relief layer is greater than −0.01 and less than 0.01. The thickness of the strain relief layer is larger than the thickness of each well layer of the multiple quantum well structure.