III-V Semiconductor Stack with Buffer Layer for Stable Epitaxy
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Solution Overview
Problem
Current semiconductor devices face challenges in achieving stable epitaxial growth and reducing lattice mismatch-induced stress, leading to defects in heteroepitaxial structures, which affects the quality and efficiency of light-emitting devices.
Innovation Solution
A semiconductor device structure is developed with a first III-V semiconductor layer, a light-emitting structure, and a second III-V semiconductor layer, where the first layer has a higher dopant concentration than the second layer, and the third layer has a lower dopant concentration than the first layer, optimized for epitaxial growth using techniques like Liquid Phase Epitaxy or Molecular Beam Epitaxy, to stabilize the surface and reduce defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If heteroepitaxial growth is performed on a GaAs substrate to form InP-based layers, then light-emitting device functionality is achieved, but lattice mismatch-induced stress and defects occur
Solution Approach 1:
The patent introduces an InGaAs buffer layer as an intermediary between the GaAs substrate and the InP-based active layers. This buffer layer has a lattice constant intermediate between GaAs and InP, serving as a transition layer that reduces lattice mismatch stress and prevents defect propagation to the active region, thereby enabling high-quality heteroepitaxial growth
Solution Approach 2:
The patent employs Liquid Phase Epitaxy (LPE) with carefully controlled growth parameters including temperature gradients, composition ratios, and doping concentrations. By optimizing these parameters, the method achieves stable epitaxial growth with reduced defects and improved crystalline quality in the heteroepitaxial structure
2Reliability
If dopant concentration is increased to improve electroconductive properties, then electrical performance improves, but epitaxial growth stability deteriorates
Solution Approach 1:
The patent applies different dopant concentrations to different layers of the semiconductor structure. The buffer and cladding layers have optimized dopant concentrations tailored to their specific functional requirements, rather than using uniform doping throughout. This local optimization allows each layer to achieve its desired electrical properties while maintaining overall epitaxial growth stability
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 structure enhances the epitaxial quality and reduces defects, allowing for improved electroconductive properties and luminous efficiency in light-emitting devices, while also addressing lattice mismatch issues, thereby improving the overall performance and stability of semiconductor devices.
Implementation Method 1
optimized for epitaxial growth using techniques like Liquid Phase Epitaxy or Molecular Beam Epitaxy
Data Source
AI summary
The present disclosure provides a semiconductor device including a first semiconductor layer, a light-emitting structure, and a second semiconductor layer. The first semiconductor layer includes a first III-V semiconductor material. The light-emitting structure is on the first semiconductor layer and includes an active structure. The second semiconductor layer is under the first semiconductor layer and includes a second III-V semiconductor material. The third semiconductor layer is between the first semiconductor layer and the light-emitting structure and includes a third III-V semiconductor material. The first semiconductor layer, the second semiconductor layer and the third semiconductor layer includes a first dopant and a third dopant. A concentration of the first dopant in the first semiconductor layer is greater than a concentration of the first dopant in the second semiconductor layer.