Semiconductor Device Zigzag Field Plate Trenches
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Solution Overview
Problem
Existing semiconductor devices with trench type field plate electrode structures face issues with non-uniform electric field distribution, leading to reduced breakdown voltage due to varying distances between field plate electrodes.
Innovation Solution
A semiconductor device design featuring a zigzag arrangement of field plate trenches with regular hexagonal cross-sections and a surrounding termination trench, ensuring constant spacing between field plate electrodes and uniform electric field distribution, thereby improving breakdown voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a column trench type field plate structure is used to reduce on-resistance, then the on-resistance decreases, but the distance between field plate electrodes becomes non-uniform and breakdown voltage is lowered
Solution Approach 1:
The patent employs a zigzag arrangement of columnar field plate electrodes instead of a straight linear arrangement. This asymmetric zigzag pattern allows the electrodes to maintain uniform spacing while extending the effective field plate length, thereby reducing on-resistance without compromising breakdown voltage through non-uniform spacing
Solution Approach 2:
The patent transitions from a one-dimensional linear arrangement of field plate electrodes to a two-dimensional zigzag arrangement. This dimensional change enables the electrodes to achieve both extended effective length (for lower on-resistance) and uniform spacing (for maintained breakdown voltage) simultaneously
2Ease of manufacture
If a stripe trench type field plate structure is used, then the structure is simple to manufacture, but the distance between field plate electrodes is constant which limits on-resistance reduction
Solution Approach 1:
The patent uses a zigzag arrangement of columnar field plate electrodes that maintains manufacturing simplicity while effectively reducing on-resistance. The zigzag pattern can be implemented using standard photolithography and etching processes, avoiding the need for complex multi-step manufacturing while achieving superior electrical performance
3Power
If columnar field plate electrodes are arranged to reduce on-resistance, then on-resistance decreases, but uniform electric field distribution is compromised leading to lower breakdown voltage
Solution Approach 1:
The zigzag arrangement of columnar field plate electrodes creates a symmetric pattern in terms of spacing while achieving asymmetric extension in effective length. This design ensures uniform electric field distribution between adjacent electrodes (maintaining breakdown voltage) while the extended zigzag path provides greater effective field plate area (reducing on-resistance)
Data Source
AI summary
According to one embodiment, there is provided a semiconductor device including a semiconductor substrate, a plurality of first columnar bodies having a peripheral edge, each of the columnar bodies spaced from one another on the semiconductor substrate, each including a first conductive layer extending from an upper end thereof in the depth direction of the semiconductor substrate, a base layer deposited about an outer peripheral surface of an upper end of the plurality of first columnar bodies, a gate adjacent to the base layer with a gate insulating film therebetween, a source layer connected to the base layer, and a second columnar body, including a second conductive layer, surrounding an outer peripheral edge of the plurality of first columnar bodies and extending in the depth direction of the semiconductor substrate.