SiC Trench Gate Structure With Epitaxial Contact for Low Source Resistance
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Solution Overview
Problem
Silicon Carbide (SiC) semiconductor devices face high source contact resistance and self-heating issues, which reduce their reliability and performance.
Innovation Solution
A semiconductor device with a trench gate structure that includes a heterogeneous epitaxial contact layer, a channel drain region, and a body region configuration to reduce source contact resistance and adjust electric field distribution, enhancing reliability and performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional planar transistor structure is used, then the device structure is simple, but the source contact resistance is high and self-heating effect reduces reliability
Solution Approach 1:
The body region is divided into multiple parts (first part, second part, third part) with different configurations relative to the trench gate structure. This segmentation allows optimization of electric field distribution and current flow paths in different regions, reducing contact resistance and self-heating effects while maintaining overall structural integrity
Solution Approach 2:
The invention transitions from a conventional planar structure to a vertical transistor structure with trench gate, utilizing the third dimension (depth) to improve performance. The trench gate extends vertically into the semiconductor layer, creating multiple sidewalls that enhance electric field distribution and reduce contact resistance without significantly increasing planar footprint
2Reliability
If the body region is configured to adjoin multiple sidewalls of the trench gate structure, then electric field distribution is optimized, but the manufacturing precision requirements increase
Solution Approach 1:
Different parts of the body region are configured with different local qualities: the first part adjoins the first sidewall, the second part adjoins the second sidewall, and the third part is positioned between the trench gate bottom and the second surface. This local differentiation optimizes electric field distribution in each region while providing clear manufacturing guidelines for each zone
Data Source
AI summary
A semiconductor device including a semiconductor layer, a trench gate structure and a conductive layer is provided. The trench gate structure is at least partially located in a trench on the first surface of the semiconductor layer. The semiconductor layer includes a source region, a body region and a drift region. The source region extends from the first surface toward the second surface. The contact layer is a heterogeneous epitaxial layer of the semiconductor layer, and the contact layer is on the first surface of the semiconductor layer and adjoins the source region. The conductive layer adjoins the contact layer and is electrically connected to the source region through the contact layer. By setting the heterogeneous epitaxial layer as the contact layer on the first surface of the semiconductor layer, the conductive layer is electrically connected to the source region through the contact layer to reduce a source contact resistance.