SiC Substrate Interface Layer Reducing Resistance
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Solution Overview
Problem
Direct bonding of SiC single crystalline and polycrystalline substrates results in high interface resistance, adversely affecting device characteristics due to potential barriers.
Innovation Solution
A semiconductor substrate with a composite interface layer containing carbon, silicon, and nitrogen atoms at a density of 1×10^21 atoms/cm^3 or more, which suppresses interface resistance by altering the SiC crystal structure and increasing the bonding strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If SiC single crystalline and SiC polycrystalline are bonded directly, then the bonding process is simple, but the interface resistance becomes high
Solution Approach 1:
An interface layer is introduced between the SiC single crystalline substrate and the SiC polycrystalline substrate to act as a mediator. This interface layer reduces the interface resistance that would otherwise be high in direct bonding, while still allowing the bonding process to proceed relatively simply.
Solution Approach 2:
The interface layer is formed as a composite material containing carbon and silicon atoms, with a specific concentration of nitrogen atoms (1×10^21 atoms/cm³ or more). This composite structure optimizes the electrical properties at the interface while maintaining mechanical bonding between the two substrates.
2Ease of manufacture
If SiC single crystalline and SiC polycrystalline are bonded directly, then the manufacturing process is straightforward, but device characteristics are adversely affected
Solution Approach 1:
The interface layer serves as an intermediary that improves device characteristics by reducing interface resistance, while adding minimal complexity to the manufacturing process. The layer is formed through controlled nitrogen atom introduction during the bonding process.
Solution Approach 2:
The nitrogen atom concentration in the interface layer is precisely controlled at 1×10^21 atoms/cm³ or more. This parameter change optimizes the electrical properties of the interface, ensuring good device characteristics while maintaining ease of manufacture through controlled atmospheric pressure processing.
3Reliability
If nitrogen atoms are introduced into the bonded region, then interface resistance is suppressed, but the interface layer composition becomes more complex
Solution Approach 1:
The nitrogen atom concentration is optimized at 1×10^21 atoms/cm³ or more, which effectively suppresses interface resistance. This specific parameter range achieves the desired electrical properties without requiring overly complex interface layer compositions.
Solution Approach 2:
The interface layer is designed as a composite material containing carbon, silicon, and nitrogen atoms in specific proportions. This composite structure achieves low interface resistance while maintaining a relatively simple and controllable composition that can be formed through controlled atmospheric pressure processing.
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
The technique improves the electric characteristics of the semiconductor substrate by reducing interface resistance and enhancing bonding strength, ensuring stable device performance.
Implementation Method 1
the nitrogen atoms may alter at least a part of a SiC crystal structure in the bonded region when the nitrogen atoms are present in the bonded region at a density of 1×10^21 atoms/cm³ or more
Implementation Method 2
Since a potential barrier is generated at a bonded interface of the single-crystalline SiC substrate and the polycrystalline SiC substrate, an interface resistance component thereby exists. However, the interface resistance can be suppressed by having the nitrogen atoms contained at 1×10^21 atoms/cm³ or more in the bonded region
Implementation Method 3
the single-crystalline SiC substrate and the polycrystalline SiC substrate are bonded via an interface layer... the interface layer is a composite material containing carbon and silicon
Data Source
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AI summary
A technique related to a bonded semiconductor substrate capable of reducing an interface resistance is provided. The semiconductor substrate comprises a single-crystalline SiC substrate and a polycrystalline SiC substrate. The single-crystalline SiC substrate and the polycrystalline SiC substrate are bonded. A bonded region of the single-crystalline SiC substrate and the polycrystalline SiC substrate contains 1×1021 (atoms/cm3) or more of particular atoms.