Epitaxial Growth on Dissimilar Substrates for Semiconductor Devices
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Solution Overview
Problem
Current semiconductor device manufacturing methods, such as wafer bonding, face challenges with high costs and low yields due to limited wafer sizes and conformability issues between semiconductor materials and dissimilar substrates, potentially leading to material bonding failures.
Innovation Solution
A method involving epitaxial growth on dissimilar substrates, where a buffer and seed layer are formed, followed by selective epitaxial growth to create semiconductor regions with low defect density, allowing for the fabrication of semiconductor devices with superior conformability and larger sizes, including multi-junction solar cells and semiconductor lasers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wafer bonding is used to manufacture semiconductor devices, then mechanical stability and hermetic sealing are ensured, but the device cost increases and yield decreases due to limited wafer size and conformability issues
Solution Approach 1:
The invention segments the semiconductor structure into separate components: a dissimilar substrate and a semiconductor layer grown epitaxially on it. This segmentation allows each component to be optimized independently - the substrate provides mechanical stability while the epitaxially grown semiconductor layer ensures conformability and eliminates bonding-related yield issues.
Solution Approach 2:
The invention introduces an intermediate buffer layer between the dissimilar substrate and the semiconductor layer. This buffer layer acts as a mediator that accommodates lattice mismatch and thermal expansion differences, enabling conformable growth without bonding failures while maintaining mechanical stability.
2Stability of the object's composition
If wafer bonding is used, then encapsulation is ensured, but the available wafer size is limited and conformability between materials is poor
Solution Approach 1:
The invention changes the fundamental parameter of material attachment from mechanical bonding to epitaxial growth. This parameter change enables the semiconductor layer to conform perfectly to the substrate surface at the atomic level, eliminating conformability issues while allowing much larger wafer sizes to be used.
3Manufacturing precision
If selective epitaxial growth is used, then conformability between semiconductor material and dissimilar substrate is improved, but device complexity increases due to multiple growth regions and defect management
Solution Approach 1:
The invention applies local quality by creating different semiconductor regions with different properties within the same device structure. High-defect-density regions are used for specific functions where defects are tolerable, while low-defect-density regions are used for critical functions requiring high performance, thereby managing complexity through functional zoning.
Solution Approach 2:
The invention converts the harmful effect of high defect density in certain regions into a beneficial feature by strategically placing these regions where defects are acceptable or even desirable for specific device functions, while protecting critical regions from defects through selective growth and etching processes.
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 production of semiconductor devices with low defect density and improved conformability, increasing yield and reducing costs by utilizing larger substrate sizes and enhancing the efficiency of semiconductor devices like solar cells and lasers.
Implementation Method 1
a semiconductor growth layer having consecutive semiconductor regions grown onto each other is grown from the opening of the insulating mask layer. The growth is selective: epitaxially, vertically and laterally
Data Source
AI summary
This invention relates to a method for manufacturing a semiconductor device and semiconductor manufactured thereby, including growing, from a seed island mesa, an abrupt hetero-junction comprising a semiconductor crystal with few crystal defects on a dissimilar substrate that can be used as light emitting and photovoltaic device.