Multi-Channel Tri-Gate Architecture for GaN Power Devices

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Solution Overview

Problem

Current III-Nitride semiconductor devices face challenges in achieving reduced on-resistance, increased power density, and enhanced breakdown voltage due to insufficient gate control in multi-channel structures and degradation of 2DEG channels, which limits their performance for high-power and RF applications.

Innovation Solution

A semiconductor structure with a multi-channel tri-gate architecture that uses 3D electrodes with sidewall and planar gates to control buried channels, allowing for simultaneous gate control over multiple 2DEG channels, reducing on-resistance, and improving current handling and thermal management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If multiple parallel conductive channels are formed within the semiconductor structure, then current density and power density are increased, but gate control over all channels becomes difficult

Engineering Contradiction:
Improvepower densityVSAvoidgate control
Core Design Contradiction:
PowerVSEase of operation

Solution Approach 1:

The patent transitions from planar 2D electrode contacts to three-dimensional electrodes that extend vertically through the heterostructure stack. This dimensional change enables simultaneous control of multiple parallel channels by providing top, bottom, and sidewall contact surfaces, solving the gate control difficulty while maintaining high current density through all channels.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The three-dimensional electrode structure nests multiple contact surfaces (top surface, bottom surface, and sidewalls) within a single vertical electrode body. This nested configuration allows the electrode to contact multiple heterostructure interfaces simultaneously, providing comprehensive gate control over stacked channels while maintaining a compact structure.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Ease of manufacture

If 2DEG channels are positioned closer to the surface for easier access, then device fabrication is simplified, but surface traps increase causing degradation of dynamic on-resistance and reliability

Engineering Contradiction:
Improvedevice fabricationVSAvoiddynamic on-resistance stability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

By extending electrodes vertically into the bulk material, the patent enables access to deeply positioned 2DEG channels without requiring surface proximity. This vertical extension allows 2DEG channels to be positioned at optimal depths away from surface traps while maintaining effective electrical contact through the three-dimensional electrode structure.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The three-dimensional electrode acts as an intermediary that bridges the surface and deep-subsurface regions. It provides a conductive pathway that reaches down to contact buried 2DEG channels without requiring those channels to be near the surface, thus eliminating the trade-off between fabrication ease and reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If conventional planar electrodes are used for contact, then device structure is simpler, but control over buried channels is insufficient

Engineering Contradiction:
Improveelectrode structureVSAvoidchannel control
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The patent replaces planar 2D electrodes with three-dimensional electrodes that extend vertically through the heterostructure stack. This dimensional transformation provides top, bottom, and sidewall contact surfaces that simultaneously control multiple buried channels, achieving superior channel control while the vertical configuration maintains relatively simple fabrication processes.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP3539159B1Semiconductor devices with multiple channels and three-dimensional electrodes
Publication Date: 2022.05.25 ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE (EPFL)
  • EP3539159B1 patent drawingFigure 1a
  • EP3539159B1 patent drawingFigure 1b
  • EP3539159B1 patent drawingFigure 2a~2b

AI summary

The present invention relates, for example, to a semiconductor structure containing multiple parallel channels in which several parallel conductive channels are formed within the semiconductor structure. Electric contact or electrostatic control over all these channels is done by three-dimensional electrode structures. The multiple channel structure with three-dimensional electrodes can be applied to semiconductors devices such as field effect transistors, diodes, and other similar electronic or quantum-effect devices. This structure is practical for materials where multiple parallel conduction channels can be formed, such as in III-V semiconductors. Ill-Nitride semiconductors with such structures are described which can lead to increased power density, reduced on-resistance and improved device performance, in addition to reducing dynamic on-resistance, and improving the stability of their threshold voltage and reliability.