SiC Semiconductor Layout for Surge Current Confinement

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Solution Overview

Problem

Power control semiconductor devices, particularly those using silicon carbide, face challenges in withstanding high surge currents due to system faults, as existing designs often lead to current concentration and overheating, resulting in device breakdown.

Innovation Solution

The semiconductor device incorporates a surge trigger layer with a higher carrier concentration, strategically located under a metal film, which restricts the surge current flow to this region, reducing current concentration and enhancing heat dissipation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the semiconductor device uses silicon carbide to reduce element resistance and increase current density, then the device performance is improved, but the device becomes more vulnerable to surge current damage

Engineering Contradiction:
Improvecurrent densityVSAvoidsurge current resistance
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The semiconductor device is divided into multiple layers with different conductivity types (n-type and p-type layers) and a specific surge trigger layer structure. This segmentation allows the surge current to be confined to specific regions rather than flowing through the entire device, protecting the high-current-density silicon carbide regions from surge damage while maintaining high power performance.

Inventive Principle:
Principle #1Segmentation

2Loss of energy

If the surge current flows through the entire semiconductor device, then the current can be dissipated, but current concentration occurs leading to overheating and device breakdown

Engineering Contradiction:
Improveenergy dissipationVSAvoidheat concentration
Core Design Contradiction:
Loss of energyVSTemperature

Solution Approach 1:

The surge trigger layer is designed with specific local properties (higher carrier concentration than surrounding layers) to create a preferred conduction path. This local quality change ensures that surge current concentrates in the trigger layer region for controlled dissipation, while the rest of the device maintains its structural integrity and operates at normal temperatures.

Inventive Principle:
Principle #3Local quality

3Reliability

If the surge trigger layer has higher carrier concentration, then the surge current is restricted to that region improving heat dissipation, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvesurge current resistanceVSAvoidcarrier concentration control
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The surge trigger layer is designed with a specific parameter change - higher carrier concentration compared to adjacent semiconductor layers. This parameter differentiation creates the necessary electrical properties for surge current confinement while being achievable through standard semiconductor manufacturing processes such as ion implantation or in-situ doping during layer growth.

Inventive Principle:
Principle #35Parameter changes

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 design significantly increases the semiconductor device's resistance to surge currents by limiting their flow to the surge trigger layer region and improving heat dissipation, thereby preventing device breakdown.

Implementation Method 1

a surge trigger layer with a higher carrier concentration, which restricts a surge current to a region where the surge trigger layer is located

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP4435872A1Semiconductor device
Publication Date: 2024.09.25 KK TOSHIBA
  • EP4435872A1 patent drawingFigure 1A~1B
  • EP4435872A1 patent drawingFigure 2
  • EP4435872A1 patent drawingFigure 3

AI summary

A semiconductor device includes a first electrode, a first semiconductor layer connected to the first electrode, a second semiconductor layer located on a portion of the first semiconductor layer, a third semiconductor layer located on a first portion of the second semiconductor layer, a fourth semiconductor layer located on a second portion of the second semiconductor layer, a fifth semiconductor layer located on a third portion of the second semiconductor layer, a second electrode, a third electrode connected to the third, fourth, and fifth semiconductor layers, and a metal film connected to the third electrode. A length in a second direction of the fifth semiconductor layer is greater than a length in the second direction of the fourth semiconductor layer. The second direction crosses a first direction. The first direction is from the first electrode toward the first semiconductor layer.