GaN-on-Si Metal Nitride Structure With Amorphous Buffer Cavities
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Solution Overview
Problem
Manufacturing high-quality GaN epitaxial layers on Si substrates is challenging due to lattice mismatch and surface mobility issues with AlN layers, which affects crystal quality.
Innovation Solution
A method involving the formation of an amorphous layer with patterns on a substrate, followed by a metal nitride layer, and subsequent removal of the amorphous layer to create cavities, allowing for the conversion of polycrystalline to monocrystalline film layers, thereby inhibiting slip and dislocation during epitaxial growth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a metal nitride layer is formed directly on a Si substrate, then the epitaxial layer can be manufactured, but the lattice mismatch between AlN and Si substrate causes low surface mobility and poor crystal quality
Solution Approach 1:
An amorphous layer is introduced as an intermediary between the Si substrate and the metal nitride layer. This amorphous layer serves as a buffer that accommodates the lattice mismatch, allowing the metal nitride layer to form with improved crystal quality while maintaining ease of manufacture.
Solution Approach 2:
The patent changes the physical and chemical parameters of the interface by introducing an amorphous layer with different material properties than direct Si-AlN contact. This parameter change enables better surface mobility for Al atom deposition while maintaining the necessary lattice structure for high-quality epitaxial growth.
2Ease of manufacture
If the amorphous layer is completely removed, then direct contact between metal nitride layer and substrate is achieved, but dislocation and slip occur during epitaxial growth
Solution Approach 1:
The amorphous layer is selectively removed in specific regions to create cavities, extracting the problematic layer only where needed while retaining it in other areas to continue providing dislocation suppression during epitaxial growth.
Solution Approach 2:
The amorphous layer is segmented into different regions: some areas are removed to form cavities for device fabrication, while other areas are retained to continue functioning as dislocation barriers. This segmentation allows simultaneous achievement of device structure and crystal quality.
3Area of stationary object
If a thick metal nitride layer is formed to compensate for lattice mismatch, then coverage is improved, but the polycrystalline structure increases dislocation density
Solution Approach 1:
The patent utilizes phase transition from polycrystalline to monocrystalline structure through controlled annealing. The metal nitride layer is first deposited as polycrystalline for easy coverage, then thermally treated to transform the crystal structure, reducing dislocation density while maintaining full coverage.
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 approach improves the quality and performance of the semiconductor structure by reducing dislocation density and enabling the production of high-quality GaN structures, facilitating the manufacturing of resonators and LED chips with simplified processes.
Implementation Method 1
during epitaxial growth
Implementation Method 2
the polycrystalline film layer of the metal nitride film layer is converted into a monocrystalline film layer by annealing process
Implementation Method 3
the amorphous layer is removed by etching process
Data Source
AI summary
The present invention provides a manufacturing method of a semiconductor structure and a semiconductor structure. The manufacturing method includes: providing a substrate; forming an amorphous layer on the substrate, wherein the amorphous layer includes a plurality of patterns to expose part of the substrate; forming a metal nitride layer on the amorphous layer; removing the amorphous layer to form a plurality of cavities between the substrate and the metal nitride layer; removing the substrate to form the semiconductor structure. In the present invention, an amorphous layer is formed on the substrate, and a metal nitride layer is formed on the amorphous layer. The amorphous layer can inhibit slip or dislocation during epitaxial growth, thereby improving the quality of the metal nitride layer and improving the performance of the semiconductor structure, while the metal nitride layer can realize self-supporting.