HEMT Hole Absorption Electrode Suppressing Kink Effect

Solution Overview

Problem

Semiconductor devices using nitride semiconductors face a challenge in maintaining high breakdown voltage and low on-state resistance due to the storage of holes generated by impact ionization, which causes a kink effect and avalanche breakdown.

Innovation Solution

The semiconductor device incorporates a structure with an electron barrier layer, an electron channel layer, and a hole absorption electrode, where the electron channel layer has a first and second portion with activated acceptor impurities, and a hole absorption electrode is used to discharge holes effectively, suppressing the kink effect and breakdown voltage drop.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a high electron mobility transistor (HEMT) using a nitride semiconductor is operated under high voltage, then a high breakdown voltage and low on-state resistance are achieved, but holes generated by impact ionization are stored in the electron channel layer causing a kink effect and avalanche breakdown

Engineering Contradiction:

Improvebreakdown voltage and on-state resistanceVSAvoidelectrical characteristic stability

Core Design Contradiction:

PowerVSReliability

Solution Approach 1:

The patent extracts and removes the harmful stored holes from the electron channel layer by introducing a hole absorption electrode. This electrode is positioned to receive and remove holes generated by impact ionization, preventing them from accumulating and causing the kink effect and avalanche breakdown, thereby maintaining device reliability under high voltage operation

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a hole absorption electrode as an intermediary component between the electron channel layer and the external environment. This mediator captures and removes harmful holes before they can cause damage, enabling the device to maintain both high power performance and electrical characteristic stability

Inventive Principle:

Principle #24Intermediary (Mediator)

2Device complexity

If holes are stored in the electron channel layer, then the device structure is simple, but the kink effect occurs and breakdown voltage drops

Engineering Contradiction:

ImprovestructureVSAvoidbreakdown voltage

Core Design Contradiction:

Device complexityVSPower

Solution Approach 1:

The patent extracts and removes the harmful stored holes from the electron channel layer by introducing a hole absorption electrode. This electrode is positioned to receive and remove holes generated by impact ionization, preventing them from accumulating and causing the kink effect and avalanche breakdown, thereby maintaining device reliability under high voltage operation

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a hole absorption electrode as an intermediary component between the electron channel layer and the external environment. This mediator captures and removes harmful holes before they can cause damage, enabling the device to maintain both high power performance and electrical characteristic stability

Inventive Principle:

Principle #24Intermediary (Mediator)

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 configuration enhances the semiconductor device's ability to absorb stored holes, stabilizing its electrical characteristics, suppressing the kink effect, and maintaining high breakdown voltage and low on-state resistance.

Implementation Method 1

a high electron mobility transistor (HEMT) using a nitride semiconductor exhibits a high breakdown voltage and a low on-resistance by utilizing a two-dimensional electron gas (2DEG) generated at a heterojunction interface

Methodology Applied

Scientific EffectTwo-dimensional electron gas (2DEG):

Implementation Method 2

An electron-hole pair is formed by a phenomenon called impact ionization in which an accelerated electron excites an electron in a valence band, when a field effect transistor using a nitride semiconductor is operated under high voltage

Methodology Applied

Scientific EffectImpact ionization: Ionisation

Implementation Method 3

a hole absorption electrode is used to discharge holes effectively, suppressing the kink effect and breakdown voltage drop

Methodology Applied

Scientific EffectHole absorption: Absorption (physical)

Data Source

PatentUS9484429B2High electron mobility transistor (HEMT) capable of absorbing a stored hole more efficiently and method for manufacturing the same

Publication Date: 2016.11.01 KK TOSHIBA

AI summary

A semiconductor device includes a first semiconductor layer, a second semiconductor layer, a third semiconductor layer, a first electrode, a second electrode, a control electrode, and a third electrode. The second semiconductor layer is provided on the first semiconductor layer and has a band gap narrower than that of the first semiconductor layer. The second semiconductor layer includes a first portion and a second portion which is provided together with the first portion and contains an activated acceptor. The third semiconductor layer is provided on the first portion and has a band gap wider than or equal to the band gap of the second semiconductor layer. The first and the second electrodes are provided on the third semiconductor layer. The control electrode is provided between the first electrode and the second electrode. The third electrode is provided on the second portion.