Semiconductor Light-Emitting Element With Oxygen-Graded AlN Buffer
Solution Overview
Problem
Current semiconductor light-emitting elements with a light emission peak wavelength between 380 nm and 425 nm lack improved light emission intensity and luminous efficiency compared to conventional blue light-emitting elements.
Innovation Solution
A semiconductor light-emitting element with a stacked structure including a reflective layer, a substrate with a fine uneven surface, and a buffer layer made of aluminum nitride with specific oxygen concentration distribution, and n-type semiconductor layers doped with Al to enhance crystallinity and light emission efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a semiconductor light-emitting element with light emission peak wavelength between 380 nm and 425 nm is developed, then the light emission intensity and luminous efficiency are improved, but the technology maturity and manufacturing capability are insufficient compared to conventional blue light-emitting elements
Solution Approach 1:
The patent applies parameter changes by precisely controlling the oxygen concentration distribution in the AlN buffer layer (O3nm at 3 nm depth and O8nm at 8 nm depth) and the aluminum concentration in the n-type semiconductor layer (0.01≤x≤0.20). By adjusting these compositional parameters, the invention achieves improved light emission intensity and luminous efficiency in the 380-425 nm wavelength range while maintaining manufacturing feasibility
Solution Approach 2:
The patent implements local quality by creating a non-uniform oxygen concentration distribution within the AlN buffer layer, where the oxygen concentration varies with depth (comparing O3nm at 3 nm depth to O8nm at 8 nm depth). This localized compositional variation optimizes the crystal quality and light emission properties specifically in the active region without affecting the entire structure uniformly
2Loss of energy
If the light emission peak wavelength is shortened to 380-425 nm range, then the luminous efficiency is improved, but the light emission intensity remains insufficient compared to conventional blue light-emitting elements
Solution Approach 1:
The patent uses composite materials by combining an AlN buffer layer with specific oxygen concentration distribution and an n-type semiconductor layer with controlled aluminum concentration (AlxGa1-xN where 0.01≤x≤0.20). This composite structure achieves both high luminous efficiency and improved light emission intensity in the 380-425 nm range
Solution Approach 2:
The invention achieves the dual improvement of luminous efficiency and light emission intensity by changing the compositional parameters: controlling oxygen concentration at different depths in the buffer layer (O3nm/O8nm ratio between 0.01 and 0.5) and aluminum concentration in the semiconductor layer (0.01≤x≤0.20), thereby optimizing both energy efficiency and output intensity
3Manufacturing precision
If a buffer layer with specific oxygen concentration distribution is formed to improve crystal quality, then the manufacturing precision is improved, but the manufacturing complexity increases
Solution Approach 1:
The patent improves crystal quality by changing the oxygen concentration parameter in the AlN buffer layer, creating a specific depth-dependent distribution (O3nm at 3 nm depth and O8nm at 8 nm depth with ratio 0.01≤O8nm/O3nm≤0.5). This parameter control enhances manufacturing precision for achieving the desired light emission characteristics
Solution Approach 2:
The invention applies preliminary action by forming the AlN buffer layer with the specific oxygen concentration distribution before growing the semiconductor layers. This pre-preparation of the buffer layer with optimized oxygen distribution establishes a high-quality foundation for subsequent layer growth, improving overall crystal quality while managing manufacturing complexity
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 increases light emission intensity, luminous efficiency, and extends the life of the semiconductor light-emitting element by improving crystallinity and reducing lattice mismatch, while maintaining effective heat dissipation.
Implementation Method 1
The buffer layer includes oxygen; and 0.01≤O8nm/O3nm≤0.5 is satisfied, where O3nm (at %) is the oxygen concentration at a depth of 3 nm of the buffer layer, and O8nm (at %) is the oxygen concentration at a depth of 8 nm of the buffer layer
Implementation Method 2
A semiconductor light-emitting element with a stacked structure including a reflective layer, a substrate with a fine uneven surface, and a buffer layer made of aluminum nitride with specific oxygen concentration distribution, and n-type semiconductor layers doped with Al to enhance crystallinity and light emission efficiency
Data Source
AI summary
A semiconductor light-emitting element according to an embodiment has a light emission peak wavelength not less than 380 nm and not more than 425 nm. The semiconductor light-emitting element includes a stacked structure including a reflective layer, a substrate provided on the reflective layer, and a semiconductor layer provided on the substrate. An uneven structure is provided in a surface of the substrate on the semiconductor layer side. The semiconductor layer includes a buffer layer made of aluminum nitride and having a thickness not less than 10 nm and not more than 100 nm. The buffer layer includes oxygen; and 0.01≤O8nm/O3nm≤0.5 is satisfied, where O3nm (at %) is the oxygen concentration at a depth of 3 nm of the buffer layer, and O8nm (at %) is the oxygen concentration at a depth of 8 nm of the buffer layer.