Silicon Carbide Glass Field Termination for High-Voltage Chip Area Savings
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Solution Overview
Problem
There is a need for area-efficient power semiconductor devices with high blocking voltage capability, as existing lateral field termination structures are material-intensive and occupy significant chip area.
Innovation Solution
The implementation of a vertical field termination structure in semiconductor devices using a single-crystalline silicon carbide portion with passivated or saturated dangling bonds and a glass structure, along with an interface layer, facilitates more vertical field termination and reduces horizontal chip area usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a lateral field termination structure is used to ensure high blocking voltage capability, then the blocking voltage is improved, but the chip area occupied increases significantly
Solution Approach 1:
The patent transitions from a conventional lateral field termination structure (extending horizontally from the junction) to a vertical field termination structure (extending downward from the junction into the drift region). This dimensional change allows the field termination to occur in the vertical dimension rather than consuming horizontal chip area, thereby maintaining high blocking voltage capability while reducing the lateral footprint of the device.
2Reliability
If a lateral field termination structure is provided to shape the electric field and avoid field crowding, then the blocking voltage is improved, but the material cost increases
Solution Approach 1:
By moving the field termination function to the vertical dimension, the patent eliminates the need for extensive lateral termination structures that consume valuable semiconductor material. The vertical termination structure achieves the same electric field shaping and crowding prevention with significantly less material, thereby reducing material costs while maintaining blocking voltage performance.
3Ease of manufacture
If dangling bonds on the lateral surface are left unsaturated, then the manufacturing process is simpler, but the electric field distribution is degraded due to field crowding
Solution Approach 1:
The patent avoids the complexity of saturating dangling bonds on lateral surfaces by eliminating the lateral surface exposure through vertical termination. The trench structure extends downward rather than outward, so the critical interfaces are vertical walls that can be passivated more effectively, and the field termination function is achieved through the vertical geometry itself rather than through lateral surface treatment.
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 enables semiconductor devices with enhanced blocking voltage capability while minimizing material costs and chip area occupation, offering a more efficient design for high voltage applications.
Implementation Method 1
Along the third surface, hydrogen atoms and/or atoms of one or more nonmetal elements other than silicon and having an atomic number greater than six saturate dangling bonds of the silicon carbide portion
Implementation Method 2
The combination of the glass structure with the passivated and/or saturated dangling bonds along the third surface voltage facilitate a more vertical field termination
Data Source
AI summary
A semiconductor device includes a single-crystalline silicon carbide portion with a first surface, an opposite second surface, and a third surface extending from the first surface in a direction of the second surface. Along the third surface, hydrogen atoms and/or atoms of one or more nonmetal elements other than silicon and having an atomic number greater than six saturate dangling bonds of the silicon carbide portion and/or a passivating coating is in direct contact with the third surface. The semiconductor device further includes a glass structure and an interface layer structure between the third surface and the glass structure.