Graded AlGaO3 Schottky Layer for Higher Reverse Breakdown

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Solution Overview

Problem

The reverse breakdown field of 3-Ga2O3 Schottky junctions is limited due to tunneling current, necessitating compositions and methods that enhance the electronic properties of semiconductor devices.

Innovation Solution

The implementation of a compositionally graded (AlxGa1-x)2O3 layer with a varying bandgap across its thickness, integrated into semiconductor devices with a Ga2O3 base layer, to increase the Schottky barrier height and improve breakdown properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a Schottky junction is formed on β-Ga2O3, then rectification behavior is achieved, but the reverse breakdown field is limited due to tunneling current

Engineering Contradiction:

Improvereverse breakdown fieldVSAvoidtunneling current

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies local quality by creating a compositionally graded layer where the aluminum content varies spatially from 0% at the interface to a maximum value toward the surface. This gradient structure provides different local bandgap values across the layer thickness, with lower bandgap regions near the interface and higher bandgap regions at the surface, thereby locally optimizing the barrier properties to suppress tunneling current while maintaining rectification behavior.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the compositional parameter (aluminum content) continuously across the layer thickness to create a graded bandgap structure. By varying the aluminum concentration from 0% to a maximum value, the bandgap parameter changes gradually, which modifies the barrier height profile and reduces the tunneling probability without compromising the Schottky barrier's rectification function.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If a compositionally graded layer is added to increase Schottky barrier height, then reverse breakdown field is enhanced, but device structure becomes more complex

Engineering Contradiction:

Improvereverse breakdown fieldVSAvoidlayer structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the semiconductor layer into a compositionally graded layer with continuous variation in aluminum content. This segmentation approach divides the layer into numerous infinitesimal sub-layers, each with a slightly different composition and bandgap value, allowing fine-tuned control of the barrier profile while maintaining a relatively simple overall device structure.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent uses a composite material structure where (AlxGa1-x)2O3 is combined with Ga2O3, creating a graded composite layer. This composite approach allows the integration of materials with different bandgap properties in a controlled gradient, achieving enhanced reverse breakdown field through material composition engineering rather than structural complexity.

Inventive Principle:

Principle #40Composite materials

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 approach effectively increases the reverse breakdown field and enhances tunneling barriers, leading to improved electric breakdown properties and device performance.

Implementation Method 1

the second semiconductor layer comprises a second semiconductor material that varies across the thickness from the bottom surface to the top surface, such that the second semiconductor material has a compositional gradient with thickness from an initial composition having an initial band gap at the bottom surface to a final comparison having a final bandgap at the top surface

Methodology Applied

Scientific EffectBandgap gradient effect: