Heterojunction Diode Transient Surge Current via PIN Segmentation

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Solution Overview

Problem

Heterojunction diodes face limitations in withstanding transient overload currents due to the electron gas layer's maximum current limitations, which restrict the non-repetitive overload current specification (Ifsm) and compromise voltage breakdown resistance when increasing current density.

Innovation Solution

Incorporating a PIN diode structure under the heterojunction diode between the anode and cathode, allowing additional conduction during transient overloads, while maintaining high current density and low conduction resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the electron gas layer current density is increased to meet higher power requirements, then the diode's forward current capability is improved, but the transient overload current (Ifsm) capacity deteriorates

Engineering Contradiction:
Improveforward current capabilityVSAvoidtransient overload current capacity
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The invention divides the diode structure into two functional regions: a first region with high electron gas layer current density for high power forward operation, and a second region with lower electron gas layer current density that can withstand high transient overload currents. This segmentation allows each region to be optimized for its specific function, resolving the contradiction between forward current capability and transient overload capacity.

Inventive Principle:
Principle #1Segmentation

2Productivity

If dopant concentration is increased to enhance on-state current, then the current conduction is improved, but the voltage breakdown resistance deteriorates

Engineering Contradiction:
Improveon-state currentVSAvoidvoltage breakdown resistance
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The invention applies different dopant concentrations in different regions: the first region has higher dopant concentration (e.g., 1e18 to 1e19 atoms/cm³) to maximize on-state current, while the second region has lower dopant concentration (e.g., 1e16 to 1e17 atoms/cm³) to maintain high voltage breakdown resistance. This local differentiation of material properties resolves the contradiction between current conduction and breakdown resistance.

Inventive Principle:
Principle #3Local quality

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

Enables a significantly higher transient overload current capacity without degrading performance, while maintaining low voltage breakdown resistance and efficient electrical conduction.

Implementation Method 1

An electron gas layer is formed at the interface between the AlGaN and GaN layers due to spontaneous and piezoelectric biasing

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

An electron gas layer is formed at the interface between the AlGaN and GaN layers due to spontaneous and piezoelectric biasing

Methodology Applied
Scientific EffectSpontaneous polarization:

Implementation Method 3

Incorporating a PIN diode structure under the heterojunction diode between the anode and cathode, allowing additional conduction during transient overloads

Methodology Applied
Scientific EffectCarrier injection:

Implementation Method 4

allowing additional conduction during transient overloads, while maintaining high current density and low conduction resistance

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3378098B1Heterojunction diode having an increased transient surge current
Publication Date: 2019.12.04 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP3378098B1 patent drawingFigure 1~3
  • EP3378098B1 patent drawingFigure 4~6
  • EP3378098B1 patent drawingFigure 7~9

AI summary

The invention relates to a heterojunction diode (1) comprising: first and second semiconductor layers (15, 17) made of III-N material, said layers being superposed to form a two-dimensional electron gas (16); an anode (23) and a cathode (21) that are selectively electrically connected to each other by way of the two-dimensional electron gas; a third semiconductor layer (14) positioned under the two-dimensional electron gas (16); a p-doped first semiconductor element (19) making contact with the anode (23) and with said third layer (14) and forming a separation between the anode and said third layer; an n-doped second semiconductor element (31) making contact with the cathode (21) and with said third layer (14), and forming a separation between the cathode and said third layer, the third semiconductor layer and the first and second semiconductor elements (19, 31) forming a p-i-n diode.