Semiconductor Source Electrode Segmentation for Corrosion Resistance

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Semiconductor devices with high electron mobility transistors face challenges in corrosion resistance and high-frequency operation due to insufficient ohmic source electrodes and high source inductance, which hinder increased output power and reliability.

Innovation Solution

A semiconductor device with a source or drain electrode formed on a semiconductor substrate, featuring a through hole that connects the electrode to a back-surface electrode, providing both ohmic and non-ohmic contact regions to enhance corrosion resistance and reduce inductance, thus enabling high-frequency operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an ohmic source electrode is formed to ensure good electrical contact, then electrical conductivity is improved, but corrosion resistance deteriorates causing electrode dissolution

Engineering Contradiction:

Improvecorrosion resistanceVSAvoidelectrode dissolution

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The source electrode is divided into two distinct contact regions: a first contact region forming an ohmic contact for low resistance electrical connection, and a second contact region forming a non-ohmic contact for corrosion resistance. This segmentation allows each region to perform its specialized function without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different contact properties are applied to different regions of the source electrode. The first contact region has high electrical conductivity with ohmic characteristics, while the second contact region has corrosion resistance with non-ohmic characteristics. This local differentiation resolves the contradiction between conductivity and corrosion resistance.

Inventive Principle:

Principle #3Local quality

2Speed

If a via hole is formed under the source electrode to reduce source inductance for high frequency operation, then frequency performance is improved, but the source electrode becomes disconnected from the back surface electrode

Engineering Contradiction:

Improvehigh frequency operation capabilityVSAvoidelectrode connection integrity

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The electrode connection is extended from a single-plane contact to a three-dimensional structure involving both the front surface and back surface of the semiconductor substrate. The via hole provides a vertical connection path through the substrate, while the first contact region maintains horizontal ohmic contact, creating a multi-dimensional connection that reduces inductance while ensuring integrity.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Ease of manufacture

If the source electrode is connected only at one contact region, then manufacturing is simplified, but corrosion resistance and high frequency performance both deteriorate

Engineering Contradiction:

Improveelectrode formation simplicityVSAvoidoverall device performance

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The source electrode connection is segmented into multiple functional regions: the first contact region for ohmic contact providing low resistance, and the second contact region for non-ohmic contact providing corrosion protection. This segmentation enables both performance requirements to be met simultaneously without significantly complicating the manufacturing process.

Inventive Principle:

Principle #1Segmentation

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

The solution improves corrosion resistance and high-frequency performance by ensuring reliable electrical connections and reduced source inductance, making the semiconductor device more suitable for high-frequency applications.

Implementation Method 1

a step of joining the semiconductor substrate to the pattern for the source electrode or the drain electrode as the first contact region by heating

Methodology Applied

Scientific EffectHeating: Heating

Implementation Method 2

a step of joining the semiconductor substrate to the pattern for the source electrode or the drain electrode as the first contact region by ion implantation

Methodology Applied

Scientific EffectIon implantation: Ion Implantation

Data Source

PatentUS11205704B2Semiconductor device and production method therefor

Publication Date: 2021.12.21 MITSUBISHI ELECTRIC CORP

AI summary

Because of inclusion of: a source electrode that is formed on a front surface of a semiconductor substrate and that is joined to the semiconductor substrate both at a source electrode as a first contact region that is an ohmic contact region and at a source electrode as a second contact region that is a contact region with a non-ohmic contact or the like; a back-surface electrode formed on a back surface of the semiconductor substrate; and a through hole in which an interconnection is provided that connects the source electrode as the second contact region in the source electrode with the back-surface electrode; it is possible not only to improve the corrosion resistance but also to reduce the leakage current, so that a highly-reliable semiconductor device suited for high frequency operation is provided.