Evaluation of Novel Metalorganic Precursors for Atomic Layer Deposition of Nickel-based Thin Films

Table of Contents

1 Introduction

I Theoretical Part

2 Nickel and Nickel Oxides

2.1 Introduction and Existence

2.2 Material properties of Nickel and Nickel Oxide

2.3 Application in electronic industry

3 Atomic Layer Deposition

3.1 History

3.2 Definition

3.3 Features of thermal-ALD

3.3.1 ALD growth mechanism – an ideal view

3.3.2 ALD growth behaviour

3.3.3 Growth mode

3.3.4 ALD temperature window

3.4 Benefits and limitations

3.5 Precursor properties for thermal-ALD

3.6 ALD & CVD of Nickel – A literature survey

4 Metrology

4.1 Thermal analysis of precursors

4.2 Film and growth characterization

4.2.1 Quartz Crystal Microbalance

4.2.2 Spectroscopic Ellipsometry

4.2.3 X-Ray Photoelectron Spectroscopy

4.2.4 Scanning Electron Microscopy

4.2.5 X-Ray Reflectometry and X-Ray Diffraction

4.2.6 Four Point Probe Technique

5 Rapid Thermal Processing

5.1 Introduction

5.2 Basics of RTP

5.3 Nickel Silicides-A literature survey

II Experimental Part

6 Methodologies

6.1 Experimental setup

6.2 ALD process

6.2.1 ALD process types and substrate setups

6.2.2 Process parameters

6.3 Experimental procedure

6.3.1 Tool preparation

6.3.2 Thermal analysis and ALD experiments from nickel precursors

6.3.3 Data acquisition and evaluation

6.3.4 Characterization of film properties

7 Results and discussion

7.1 Introduction

7.2 QCM verification with Aluminum Oxide ALD process

7.3 ALD process from the reference precursor

7.3.1 Introduction

7.3.2 TG analysis for Ni(amd) precursor

7.3.3 Thermal stability test for Ni(amd)

7.3.4 ALD process optimization

7.3.5 Film properties

7.4 Evaluating the novel Nickel precursors

7.4.1 Screening tests for precursor P1

7.4.2 Screening tests for precursor P2

7.4.3 Screening tests for precursor P3

7.4.4 Screening tests for precursor P4

7.4.5 Screening tests for precursor P5

7.5 Comparison of all nickel precursors used in this work

8 Conclusions and outlook

A Deposition temperature control & Ellipsometry model

B Gas flow plan

Research Objectives and Topics

The primary goal of this master thesis is the evaluation of several novel Nickel precursors for Atomic Layer Deposition (ALD) to facilitate the production of thin films suitable for source and drain contact metallization in 28 nm semiconductor technology and beyond. Since existing Nickel precursors have been limited in availability and film quality, this work aims to develop an efficient testing methodology to screen these new materials.

• Development of a time-efficient testing procedure for novel metalorganic precursors using small sample quantities.
• Optimization of a benchmark ALD process using a reference precursor to establish standard process parameters.
• Thermal analysis (TGA/DTA) and thermal stability testing of novel Nickel precursors.
• Comprehensive film characterization, including chemical composition, physical phase, thickness, density, and sheet resistance, using various metrological techniques (XPS, XRR, SEM, 4PP).
• Assessment of the feasibility of these precursors for nickel silicide formation in comparison to state-of-the-art processes.

Excerpt from the Book

Summary of Chapters

1 Introduction: Provides an overview of the application of Nickel and Nickel(II) oxide in microelectronics and introduces the need for evaluating novel precursors for ALD.

2 Nickel and Nickel Oxides: Details the material properties, physical characteristics, and electronic industry applications of Nickel and its oxides.

3 Atomic Layer Deposition: Discusses the history, definition, features, and advantages/limitations of the ALD technique, including a survey of existing literature on Nickel ALD.

4 Metrology: Describes the analytical experimental techniques used, specifically thermal analysis (TGA/DTA) and various film characterization methods like QCM, Ellipsometry, and XPS.

5 Rapid Thermal Processing: Covers the basics of RTP and provides a literature survey on Nickel silicide formation, including its application in semiconductor devices.

6 Methodologies: Explains the experimental setup, ALD process parameters, and the detailed procedures used for testing precursors and evaluating thin film properties.

7 Results and discussion: Presents the findings of the benchmark ALD process and the comprehensive screening/evaluation of the five novel Nickel precursors.

8 Conclusions and outlook: Summarizes the findings regarding the precursors and offers recommendations for future research in optimizing Nickel precursor stability for ALD.

Keywords

Atomic Layer Deposition, ALD, Nickel, Metalorganic Precursors, Thin Films, Nickel Silicide, Thermal Analysis, TGA, DTA, Spectroscopic Ellipsometry, X-Ray Photoelectron Spectroscopy, XPS, Quartz Crystal Microbalance, Semiconductor Technology

Frequently Asked Questions

What is the core subject of this thesis?

The thesis focuses on the evaluation of several novel metalorganic Nickel precursors for Atomic Layer Deposition (ALD) to improve the quality of Nickel-based thin films used in microelectronic applications.

What are the central thematic fields?

The research encompasses thin film deposition techniques (ALD), precursor chemistry, thermal analysis (TGA/DTA), and metrology (characterization methods like XPS, XRR, and Ellipsometry) applied to semiconductor manufacturing.

What is the primary objective of the work?

The goal is to determine if the provided novel Nickel precursors are suitable for thermal ALD, specifically by assessing their thermal stability, sublimation properties, and the resulting film quality.

Which scientific methodology is applied?

The work employs a multi-step methodology: TGA/DTA analysis, thermal stability testing in sealed ampoules, benchmark process development using a reference precursor (Ni(amd)), and subsequent screening of novel precursors with in-situ QCM monitoring and ex-situ characterization.

What is covered in the main body of the thesis?

The main body is divided into a theoretical part, covering ALD and Nickel properties, and an experimental part, detailing the setup, precursor screening tests (P1-P5), and data evaluation regarding their growth behavior and film characteristics.

Which keywords best characterize this research?

Keywords include Atomic Layer Deposition (ALD), Nickel, Nickel Silicide, Metalorganic Precursors, Thin Films, Thermal Analysis, and various characterization techniques like XPS and Ellipsometry.

Why are standard precursors often unsuitable for ALD?

Existing precursors often exhibit limited thermal stability, leading to self-decomposition, poor film homogeneity, and significant impurity incorporation, which deviates from the ideal self-limiting ALD growth mechanism.

What were the main conclusions regarding the tested precursors (P1-P5)?

The evaluation revealed that most tested precursors underwent thermal decomposition or structural changes at operating temperatures, making them generally unsuitable for achieving high-quality metallic nickel films through standard thermal ALD.