Metal Oxide Interface Layer for Ferroelectric Semiconductor Reliability

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Solution Overview

Problem

Ferroelectric devices face reliability issues due to poor interface quality between ferroelectric materials and semiconductor channels, leading to defects, interfacial breakdown, bias temperature instability, and low endurance, particularly with compound semiconductor materials like indium gallium zinc oxide prone to bond breaking and hydrogen interactions.

Innovation Solution

A dielectric metal oxide layer is introduced between the electrode and semiconductor layer, enriched with oxygen to improve the interface quality, formed through physical vapor deposition and oxidation processes, reducing interfacial defects and enhancing device reliability by mitigating electrical field stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a ferroelectric material is placed in direct contact with a semiconductor channel material, then device structure is simplified, but interface quality deteriorates leading to high defect density and poor reliability

Engineering Contradiction:

Improvedevice structureVSAvoidinterface quality

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

A metal oxide interface layer is introduced between the ferroelectric material and the semiconductor channel material to act as an intermediary layer. This interface layer improves interfacial quality, reduces defect density, and prevents direct harmful contact between the ferroelectric material and the semiconductor channel, thereby resolving the reliability issue while maintaining structural simplicity.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Power

If a high electrical field is applied to the ferroelectric material, then ferroelectric switching performance is improved, but interfacial breakdown between ferroelectric material and semiconductor channel occurs

Engineering Contradiction:

Improveferroelectric switching performanceVSAvoidinterfacial breakdown

Core Design Contradiction:

PowerVSReliability

Solution Approach 1:

The metal oxide interface layer is formed beforehand to provide a protective buffer between the ferroelectric material and the semiconductor channel. This cushioning layer prevents interfacial breakdown that would otherwise occur under high electrical field conditions, allowing the ferroelectric switching performance to be maintained without causing damage to the interface.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If compound semiconductor materials such as indium gallium zinc oxide are used, then device performance is enhanced, but bond breaking and hydrogen bond formation occur reducing reliability

Engineering Contradiction:

Improvedevice performanceVSAvoidbond stability

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The metal oxide interface layer serves as a protective intermediary between the ferroelectric material and the compound semiconductor material (such as indium gallium zinc oxide). This interface layer prevents hydrogen from reaching the compound semiconductor material, thereby preventing bond breaking and hydrogen bond formation that would otherwise occur and reduce reliability.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Ease of manufacture

If no interface layer is used between ferroelectric material and semiconductor channel, then manufacturing process is simplified, but bias temperature instability and low endurance characteristics occur

Engineering Contradiction:

Improvemanufacturing processVSAvoidbias temperature instability and endurance

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

A metal oxide interface layer is introduced to prevent bias temperature instability and improve endurance characteristics. The interface layer acts as a protective barrier that stabilizes the interface between the ferroelectric material and the semiconductor channel, thereby resolving the reliability issues without significantly complicating the manufacturing process.

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

The solution enhances the reliability of ferroelectric memory elements by reducing defects and interfacial breakdown, improving endurance, and addressing weaknesses associated with indium gallium zinc oxide materials.

Implementation Method 1

formed through physical vapor deposition and oxidation processes

Methodology Applied

Scientific EffectPhysical vapor deposition: Physical Vapour Deposition

Implementation Method 2

formed through physical vapor deposition and oxidation processes

Methodology Applied

Scientific EffectOxidation: Oxidation

Data Source

PatentUS20250014945A1Semiconductor device including a metal oxide interface layer and methods for forming the same

Publication Date: 2025.01.09 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

A device structure can be formed by forming a layer stack comprising a continuous bottom electrode material layer, a continuous dielectric layer, and a continuous dielectric metal oxide layer; increasing an oxygen-to-metal ratio in a top surface portion of the continuous dielectric metal oxide layer by incorporating oxygen atoms into the top surface portion of the continuous dielectric metal oxide layer; depositing a continuous semiconductor layer over the continuous dielectric metal oxide layer; and patterning the continuous semiconductor layer and the layer stack to form a patterned layer stack including a bottom electrode, a dielectric layer, a dielectric metal oxide layer, and a semiconductor layer.