MIM Capacitor MOCVD ALD Electrode Contamination

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Solution Overview

Problem

Current MIM capacitor manufacturing techniques face challenges in achieving high throughput and maintaining electrical properties due to limitations in atomic layer deposition (ALD) and metal organic chemical vapor deposition (MOCVD) methods, leading to contamination issues and increased leakage current.

Innovation Solution

A method involving rapid thermal processing (RTP) of the conductive layers, combined with MOCVD for the bottom electrode and ALD for the top electrode, along with plasma treatment to remove contamination, is used to enhance the electrical properties and throughput of MIM capacitors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If MOCVD is used to deposit metal nitride layers, then manufacturing throughput is improved, but electrical properties and purity of the deposited films deteriorate due to contamination

Engineering Contradiction:

Improvemanufacturing throughputVSAvoidelectrical properties

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

A cap layer is deposited over the MOCVD metal nitride layer before subsequent processing steps. This cap layer prevents contamination from affecting the underlying metal nitride layer during plasma treatment and other manufacturing processes, thereby maintaining electrical properties while allowing MOCVD to be used for high throughput deposition

Inventive Principle:

Principle #10Preliminary action

2Reliability

If plasma treatment is performed to remove contamination from MOCVD deposits, then purity is improved, but the underlying dielectric layer is damaged and anisotropic contamination remains on sidewalls

Engineering Contradiction:

ImprovepurityVSAvoiddamage to dielectric layer

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The cap layer serves as an intermediary protective barrier between the plasma treatment process and the underlying dielectric layer. It allows plasma to remove contamination from the metal nitride layer while preventing direct damage to the dielectric, thus achieving purification without harmful side effects

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If ALD is used to deposit metal nitride layers, then electrical properties and purity are improved, but manufacturing throughput deteriorates

Engineering Contradiction:

Improveelectrical propertiesVSAvoidmanufacturing throughput

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The capacitor structure is segmented into different regions with different deposition methods: MOCVD is used for the bottom electrode where high throughput is critical, while ALD is used for the top electrode where superior electrical properties are more critical. This segmentation allows each method to be applied where it provides the most benefit

Inventive Principle:

Principle #1Segmentation

4Reliability

If thicker dielectric layer is used to compensate for leakage current, then reliability is improved, but scalability and device size reduction are hindered

Engineering Contradiction:

Improveleakage current reductionVSAvoiddevice size

Core Design Contradiction:

ReliabilityVSLength of moving object

Solution Approach 1:

The cap layer, which was initially intended to protect against plasma damage, unexpectedly serves as an effective barrier against leakage current. This converts the added structural element into a beneficial feature that improves reliability without requiring increased dielectric thickness, thereby maintaining scalability

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 improves the purity and quality of the metal nitride layers, reduces carbon contamination, and increases the breakdown voltage of MIM capacitors, enabling better electrical performance and scalability.

Implementation Method 1

performing rapid thermal processing of the first conductive layer

Methodology Applied

Scientific EffectRapid thermal processing: Heating

Implementation Method 2

forming a first conductive layer in the trench by metal organic chemical vapor deposition (MOCVD)

Methodology Applied

Scientific EffectMetal organic chemical vapor deposition: Chemical Vapour Deposition

Implementation Method 3

forming a second conductive layer on the insulator layer by atomic layer deposition (ALD)

Methodology Applied

Scientific EffectAtomic layer deposition: Physical Vapour Deposition

Implementation Method 4

plasma treatment is required to remove impurities introduced during the deposition process

Methodology Applied

Scientific EffectPlasma: Plasma

Data Source

PatentUS7851324B2Method of forming metal-insulator-metal structure

Publication Date: 2010.12.14 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

A method of manufacturing a semiconductor device includes forming a metal-insulator-metal (MIM) device having a metal organic chemical vapor deposited (MOCVD) lower electrode and an atomic layer deposited (ALD) upper electrode.