Single Crystalline Buffer Layer for Nitride Semiconductor Strain Reduction
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Solution Overview
Problem
Current semiconductor light emitting devices face challenges in achieving optimal light efficiency and manufacturing processes for nitride semiconductors, particularly in minimizing strain and maintaining wetting properties during the growth of epitaxial layers on substrates with differing lattice constants and thermal expansion coefficients.
Innovation Solution
A semiconductor light emitting device is developed with a single crystalline buffer layer composed of AlY(GaxIn1-X)N, grown using MOCVD equipment, which changes growth temperature and atmosphere from H2 to N2 to prevent desorption and ensure two-dimensional growth, minimizing strain and enhancing crystalline quality, and is integrated with a light emitting structure comprising conductive semiconductor layers and an active layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If epitaxial layers are grown on substrates with differing lattice constants, then light emitting device performance can be improved, but strain accumulates and degrades crystalline quality
Solution Approach 1:
A buffer layer is introduced as an intermediary between the substrate and the light emitting structure. This buffer layer has intermediate lattice properties that gradually transition from the substrate to the epitaxial layers, reducing the abrupt lattice mismatch and minimizing strain accumulation while maintaining good crystalline quality in the final device structure.
Solution Approach 2:
The buffer layer composition is specifically designed with variable parameters (Al content Y and In content X) that can be tuned to optimize lattice matching. By changing the compositional parameters of AlY(GaXIn1-X)N, the buffer layer adapts its lattice constant to better match both the substrate and the overlying GaN layers, reducing strain while preserving crystalline quality.
2Manufacturing precision
If growth temperature is increased to improve crystalline quality, then light emitting performance improves, but desorption of adatoms occurs reducing growth efficiency
Solution Approach 1:
The growth atmosphere is changed from H2 to N2, which has lower reactivity with the nitride semiconductor materials at high temperatures. This inert N2 environment prevents unwanted chemical reactions and reduces desorption of adatoms, allowing high growth temperatures to be maintained for improved crystalline quality without significant loss of growth efficiency.
3Manufacturing precision
If multiple buffer layers are used to reduce strain, then crystalline quality improves, but device complexity increases
Solution Approach 1:
The buffer layer uses a composite material approach with AlY(GaXIn1-X)N, combining AlN, GaN, and InN components in a single quaternary compound. This composite structure provides graded lattice matching properties that reduce strain effectively, while maintaining a single-layer configuration that avoids the complexity of multiple discrete buffer layers.
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 effectively reduces strain and improves crystalline quality, leading to enhanced light emitting performance and manufacturing efficiency by maintaining the wetting property and preventing degradation, thus improving the overall efficiency of the semiconductor light emitting device.
Implementation Method 1
changes growth temperature and atmosphere from H2 to N2 to prevent desorption and ensure two-dimensional growth
Implementation Method 2
grown using MOCVD equipment
Implementation Method 3
changes growth temperature and atmosphere from H2 to N2 to prevent desorption
Data Source
AI summary
Disclosed are a semiconductor light emitting device comprising a single crystalline buffer layer and a manufacturing method thereof. The semiconductor light emitting device comprises a single crystalline buffer layer, and a compound semiconductor structure comprising III and V group elements on the single crystalline buffer layer.