3C-SiC Laminate Substrate Manufacturing via Epitaxial Growth and Bonding
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Solution Overview
Problem
Existing methods for manufacturing 3C-SiC laminate substrates face challenges in achieving large diameters while minimizing defects, particularly due to lattice mismatch and thermal expansion differences between SiC and silicon substrates.
Innovation Solution
A method involving epitaxial growth of a 3C-SiC single crystal film on a first single crystal silicon substrate, followed by bonding a support substrate and removing the first silicon substrate to produce a 3C-SiC laminate substrate with a large diameter and reduced defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If thick SiC is grown on silicon substrate to achieve large-diameter substrates, then substrate diameter is improved, but defect generation increases due to lattice mismatch and thermal expansion differences
Solution Approach 1:
The substrate structure is segmented into multiple functional layers: a silicon substrate for large-diameter support, a buffer layer for lattice matching, and a thick SiC layer for the desired thickness. This segmentation allows each layer to perform its specific function - the silicon substrate provides mechanical support for large diameter, while the buffer layer mitigates defect propagation from lattice mismatch.
Solution Approach 2:
A buffer layer is introduced as an intermediary between the silicon substrate and the thick SiC layer. This buffer layer acts as a mediator that gradually transitions from the silicon lattice structure to the SiC lattice structure, reducing the abrupt lattice mismatch and preventing defect generation in the thick SiC layer.
2Manufacturing precision
If bulk growth method is used for 3C-SiC, then crystal quality is improved, but high temperature requirement makes large-diameter manufacturing difficult
Solution Approach 1:
The growth parameters are changed by using heteroepitaxial growth on a silicon substrate at lower temperatures compared to bulk growth. This parameter change allows the process to be performed at temperatures suitable for large-diameter silicon substrates while still achieving acceptable crystal quality through the controlled epitaxial process.
Solution Approach 2:
The silicon substrate serves multiple functions: it provides mechanical support for large-diameter manufacturing, acts as a template for epitaxial growth, and enables the use of existing silicon fabrication infrastructure. This multi-functionality allows the process to achieve both large-diameter capability and crystal quality.
3Ease of manufacture
If heteroepitaxial growth is used on silicon substrate, then manufacturing cost is reduced and large diameter is enabled, but defect generation occurs due to lattice mismatch
Solution Approach 1:
A buffer layer is formed preliminarily before growing the thick SiC layer. This preliminary action of creating the buffer layer prepares the interface to accommodate lattice mismatch, preventing defects from forming during the subsequent thick SiC layer growth while maintaining the cost-effective heteroepitaxial process.
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 method enables the reliable and cost-effective manufacturing of 3C-SiC laminate substrates with diameters of 200 mm or larger, while minimizing defect generation and reducing manufacturing costs.
Implementation Method 1
epitaxially growing a 3C-SiC single crystal film on a first single crystal silicon substrate
Data Source
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AI summary
The present invention is a method for manufacturing a 3C-SiC laminate substrate, the method includes the steps of epitaxially growing a 3C-SiC single crystal film on a first single crystal silicon substrate, bonding a support substrate on an upper surface of the 3C-SiC single crystal film, and removing the first single crystal silicon substrate to manufacture the 3C-SiC laminate substrate. Therefore, an object is to provide a method for manufacturing a 3C-SiC laminate substrate. In particular, this provides a method for obtaining a 3C-SiC laminate substrate having a large diameter such as 200 mmϕ or 300 mmϕ.