Diamond Semiconductor Buffer Layer on Silicon
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Solution Overview
Problem
The high lattice mismatch between diamond and silicon substrates makes it difficult to form a uniform and high-quality diamond semiconductor layer on a low-cost silicon substrate, which is necessary for cost-effective semiconductor device manufacturing.
Innovation Solution
A laminated body is created with a silicon layer, a first beryllium oxide layer acting as a buffer, and a diamond semiconductor layer, where the beryllium oxide layer receives compressive stress from the silicon, allowing for hetero-epitaxial growth of diamond with reduced misfit and improved crystalline quality, enabling the formation of large-area diamond crystals suitable for semiconductor elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a diamond layer is formed on a silicon substrate, then cost is reduced and productivity is improved, but the lattice mismatch causes poor manufacturing precision and low quality of the diamond semiconductor layer
Solution Approach 1:
A buffer layer comprising alternating first and second layers (with different lattice constants) is introduced between the silicon substrate and the diamond semiconductor layer. This intermediary structure gradually transitions the lattice constant from silicon to diamond, reducing misfit dislocations and enabling high-quality diamond layer formation on silicon substrates.
Solution Approach 2:
The buffer layer is segmented into multiple alternating layers with different lattice constants rather than using a single uniform layer. This segmentation allows progressive lattice constant transition, better managing the lattice mismatch between silicon and diamond while maintaining manufacturing feasibility.
2Adaptability or versatility
If a diamond layer is formed on an Ir substrate by CVD method and peeled, then diamond semiconductor layers can be transferred, but substrate cost is high and quality lowers during peeling process
Solution Approach 1:
The buffer layer acts as an intermediary that enables diamond layer formation on silicon without requiring peeling from expensive substrates. The alternating layer structure provides controlled stress management that allows direct growth of high-quality diamond on silicon, eliminating the peeling process entirely.
Solution Approach 2:
The invention replaces expensive Ir substrates with low-cost silicon substrates. The buffer layer structure enables silicon to serve as a disposable, low-cost foundation that doesn't require recovery or reuse, unlike the expensive Ir substrates in conventional methods.
3Manufacturing precision
If a uniform diamond semiconductor layer is formed on Si substrate, then high quality semiconductor devices can be manufactured, but the high lattice mismatch rate makes this difficult
Solution Approach 1:
The buffer layer with alternating structures serves as a mediator that progressively bridges the lattice mismatch between silicon and diamond. Each alternating layer pair provides a transition step, reducing the abruptness of lattice constant change and enabling uniform diamond layer growth despite the inherent lattice mismatch complexity.
Solution Approach 2:
The buffer layer structure changes the lattice constant parameter gradually through alternating layers rather than maintaining a constant lattice structure. This parameter transition approach manages the lattice mismatch by creating intermediate lattice constant values between silicon and diamond.
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 allows for the growth of high-quality, large-area diamond semiconductor layers with high effective mobility, facilitating the production of semiconductor devices with improved characteristics and heat dissipation capabilities.
Implementation Method 1
the beryllium oxide layer receives compressive stress from the silicon
Implementation Method 2
allowing for hetero-epitaxial growth of diamond with reduced misfit and improved crystalline quality
Data Source
AI summary
A laminated body of an embodiment includes: a silicon layer; a first beryllium oxide layer on the silicon layer; and a diamond semiconductor layer on the first beryllium oxide layer.