AlN Nucleating Layer for Epitaxy Quality in Semiconductor Devices
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Solution Overview
Problem
Conventional semiconductor light emitting devices face issues with epitaxy quality due to lattice constant and thermal expansion coefficient mismatches between semiconductor layers and substrates, leading to dislocations and thermal stress, which can cause bending and cracking during the manufacturing process.
Innovation Solution
A nucleating layer with a single crystal aluminum nitride structure, formed by sputtering, is used on the substrate, featuring a diffraction pattern of circular dot patterns with a diameter ratio of 0.9 to 1.1, improving the epitaxy quality and reducing stress, and a buffer layer is introduced to mitigate lattice mismatch.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional semiconductor layers are grown directly on substrate, then manufacturing process is simple, but dislocations and thermal stress occur due to lattice constant and CTE mismatch
Solution Approach 1:
The patent segments the interface between substrate and semiconductor layer by introducing a nucleating layer composed of multiple crystal planes. This nucleating layer acts as an intermediate structure that divides the direct contact interface into multiple graded interfaces, allowing progressive transition from substrate lattice to semiconductor layer lattice, thereby reducing dislocation and improving epitaxy quality.
Solution Approach 2:
The nucleating layer serves as an intermediary structure between the substrate and the semiconductor layer. It mediates the lattice mismatch and thermal expansion coefficient difference by providing a graded transition zone with multiple crystal planes, reducing the harmful effects of direct interface mismatch while maintaining structural integrity.
2Manufacturing precision
If nucleating layer with single crystal structure is formed by sputtering, then epitaxy quality is improved, but manufacturing process complexity increases
Solution Approach 1:
The patent applies parameter changes by controlling the sputtering process to form a nucleating layer with specific single crystal structure and multiple crystal planes. By adjusting sputtering parameters (power, time, temperature, gas flow), the nucleating layer achieves the desired crystal orientation and structure that promotes high-quality epitaxy while managing manufacturing complexity through process optimization.
3Manufacturing precision
If buffer layer is introduced to mitigate lattice mismatch, then epitaxy quality is improved, but device structure becomes more complex
Solution Approach 1:
The patent merges the functions of the nucleating layer and buffer layer into a single integrated structure. The nucleating layer with multiple crystal planes simultaneously performs the functions of initiating crystal growth (nucleating) and providing lattice matching (buffering), thereby achieving improved epitaxy quality while reducing the number of separate layers and simplifying the overall device 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
The solution results in improved epitaxy quality and working efficiency of semiconductor light emitting devices by ensuring well-organized lattice structures and reducing the likelihood of cracking, thereby enhancing the reliability and performance of the devices.
Implementation Method 1
the nucleating layer is formed on the substrate by sputtering
Data Source
AI summary
An epitaxy base including a substrate and a nucleating layer disposed on the substrate. The nucleating layer is an AlN layer with a single crystal structure. A diffraction pattern of the nucleating layer includes a plurality of dot patterns. Each of the dot patterns is substantially circular, and a ratio between lengths of any two diameters perpendicular to each other on each of the dot patterns ranges from approximately 0.9 to approximately 1.1. A semiconductor light emitting device, a manufacturing method of the epitaxy base, and a manufacturing method of the light emitting semiconductor device are further provided.