Semiconductor Device Trench Gate Asymmetry Optimization
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Solution Overview
Problem
Wide-bandgap semiconductor devices with asymmetric transistor cells and trench gates face limitations in device characteristics and application expansion, particularly in managing switching losses and leakage currents at high temperatures.
Innovation Solution
The semiconductor device incorporates trench gate structures that separate mesa portions, forming pn junctions with body regions and source regions, and includes trench source structures electrically connected to a load electrode, optimizing the layout to enhance device performance and expand application ranges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If asymmetric transistor cells with stripe-shaped trench gate electrodes are used to control transistor channels in only one of two opposite longitudinal mesa sidewalls, then device characteristics can be optimized for specific applications, but the range of applications is limited and device complexity increases
Solution Approach 1:
The patent applies asymmetry by configuring source regions to directly adjoin only one of the two opposite longitudinal mesa sidewalls, creating asymmetric transistor cells. This asymmetric design optimizes device characteristics for specific applications while the patent also describes how symmetric configurations can be achieved by adjoining source regions to both sidewalls, thereby expanding the range of applicable applications.
2Temperature
If wide-bandgap semiconductor material is used to achieve lower on-state resistance at high temperatures, then high-temperature performance is improved, but switching losses and leakage currents remain problematic
Solution Approach 1:
The patent applies local quality by creating regions with different doping characteristics within the semiconductor structure. Specifically, it forms body regions and source regions with complementary doping types that create pn junctions, allowing different parts of the device to have optimized electrical properties for reducing switching losses while maintaining high-temperature performance.
Solution Approach 2:
The patent changes electrical parameters by forming pn junctions through complementary doping regions. By adjusting the doping concentrations and distributions in body and source regions, the device achieves optimized switching characteristics and reduced switching losses while maintaining low on-state resistance at high temperatures.
3Stability of the object's composition
If wide-bandgap semiconductor material is used to achieve lower leakage currents, then high-temperature stability is improved, but device complexity increases due to additional trench structures
Solution Approach 1:
The patent applies universality by designing trench structures that serve multiple functions: they provide mechanical support, define active regions, and create pn junctions for electrical control. The trench gate structures and associated body/source regions simultaneously achieve leakage current reduction, high-temperature stability, and application-specific optimization without requiring separate structures for each function.
Data Source
AI summary
A semiconductor device includes a semiconductor body formed from a semiconductor material with a band-gap of at least 2.0 eV, the semiconductor body having a diode region and a source region. The semiconductor device further includes a trench gate structure having a first sidewall and a second sidewall opposite the first sidewall, the first sidewall and the second sidewall extending along a common longitudinal direction. A doping concentration of a first doping type is higher in the diode region than in the source region. The trench gate structure projects from a first surface of the semiconductor body into the semiconductor body. A first portion of the second sidewall at the first surface is directly adjoined by the source region. A second portion of the second sidewall is in direct contact with the diode region. Additional semiconductor device embodiments are provided.