GaN Semiconductor Devices with Heat Dissipation Substrates

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Solution Overview

Problem

Gallium nitride (GaN) based semiconductor devices face challenges with heat dissipation and voltage withstanding characteristics due to the use of sapphire substrates with low thermal conductivity, and alternative substrates like SiC are expensive, increasing the overall cost and manufacturing complexity.

Innovation Solution

The use of a heat dissipation substrate with higher thermal conductivity, such as amorphous or crystalline AlN, Si, Ge, or ceramic substrates, combined with a GaN-based multi-layer structure having N-face polarity and a highly resistive GaN-based material layer, along with a gate and source/drain configuration, enhances heat dissipation and voltage withstanding characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a sapphire substrate is used for GaN-based semiconductor devices, then the device structure is simple and manufacturing cost is low, but heat dissipation characteristic is poor due to low thermal conductivity

Engineering Contradiction:

Improvemanufacturing costVSAvoidheat dissipation characteristic

Core Design Contradiction:

Ease of manufactureVSTemperature

Solution Approach 1:

The device is divided into multiple functional layers including a buffer layer, AlGaN barrier layer, and GaN layer, with each layer serving specific purposes for heat management and electrical performance

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A composite structure is formed by combining different materials (sapphire substrate, buffer layer, AlGaN barrier layer, GaN layer) to achieve both cost-effectiveness and improved heat dissipation characteristics

Inventive Principle:

Principle #40Composite materials

2Temperature

If a SiC substrate is used instead of sapphire substrate, then heat dissipation characteristic is improved, but manufacturing cost increases about 10 times

Engineering Contradiction:

Improveheat dissipation characteristicVSAvoidmanufacturing cost

Core Design Contradiction:

TemperatureVSEase of manufacture

Solution Approach 1:

A highly resistive GaN-based material layer is introduced locally between the sapphire substrate and the AlGaN barrier layer to improve heat dissipation and voltage withstanding characteristics at critical interfaces without requiring expensive SiC substrates

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The resistance parameter of the GaN-based material layer is optimized to be greater than or equal to 10^9 Ω/sq to achieve both cost-effectiveness and improved thermal and electrical performance

Inventive Principle:

Principle #35Parameter changes

3Power

If a GaN-based semiconductor device is designed for high power application, then power handling capability is improved, but voltage withstanding characteristic and manufacturing process complexity are affected

Engineering Contradiction:

Improvepower handling capabilityVSAvoidmanufacturing process complexity

Core Design Contradiction:

PowerVSDevice complexity

Solution Approach 1:

The resistance parameter of the GaN-based material layer is optimized to be greater than or equal to 10^9 Ω/sq to achieve both cost-effectiveness and improved thermal and electrical performance

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

A composite structure is formed by combining different materials (sapphire substrate, buffer layer, AlGaN barrier layer, GaN layer) to achieve both heat dissipation and voltage withstanding capabilities

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 configuration allows for improved heat dissipation and voltage withstanding capabilities, reducing manufacturing costs and enhancing the operational characteristics of GaN-based semiconductor devices.

Implementation Method 1

a GaN-based multi-layer, which is arranged on the heat dissipation substrate, have N-face polarity, and include a 2-dimensional electron gas (2DEG)

Methodology Applied

Scientific Effect2-dimensional electron gas (2DEG):

Implementation Method 2

a cathode which forms Schottky contact with a first region of the GaN-based multi-layer

Methodology Applied

Scientific EffectSchottky contact:

Implementation Method 3

an anode which forms ohmic contact with a second region of the GaN-based multi-layer

Methodology Applied

Scientific Effectohmic contact:

Data Source

PatentUS9029916B2Gallium nitride based semiconductor devices and methods of manufacturing the same

Publication Date: 2015.05.12 SAMSUNG ELECTRONICS CO LTD

AI summary

Gallium nitride (GaN) based semiconductor devices and methods of manufacturing the same. The GaN-based semiconductor device may include a heat dissipation substrate (that is, a thermal conductive substrate); a GaN-based multi-layer arranged on the heat dissipation substrate and having N-face polarity; and a heterostructure field effect transistor (HFET) or a Schottky electrode arranged on the GaN-based multi-layer. The HFET device may include a gate having a double recess structure. While such a GaN-based semiconductor device is being manufactured, a wafer bonding process and a laser lift-off process may be used.