Glancing Angle Deposition of Thin Films

This book provides a highly practical treatment of Glancing Angle Deposition (GLAD), a thin film fabrication technology optimized to produce precise nanostructures from a wide range of materials. GLAD provides an elegant method for fabricating arrays of nanoscale helices, chevrons, columns, and other porous thin film architectures using physical vapour deposition processes such as sputtering or evaporation. The book gathers existing procedures, methodologies, and experimental designs into a single, cohesive volume which will be useful both as a ready reference for those in the field and as a definitive guide for those entering it. It covers:

• Development and description of GLAD techniques for nanostructuring thin films

• Properties and characterization of nanohelices, nanoposts, and other porous films

• Design and engineering of optical GLAD films including fabrication and testing, and chiral films

• Post-deposition processing and integration to optimize film behaviour and structure

• Deposition systems and requirements for GLAD fabrication

• A patent survey, extensive relevant literature, and a survey of GLAD's wide range of material properties and diverse applications.

Auteur

Dr Matthew M. Hawkeye is a postdoc at University of Alberta who earned his Ph.D. in electrical engineering working with the Brett group on GLAD technology and who has worked on the GLAD technique since 2004. From 2010-2012, he worked as a postdoc at the University of Cambridge, during which time he authored numerous articles on nanoscale photonics and contributed to a BBC Horizon series special on synthetic biology. His publications include a review article in Journal of Vacuum Science and Technology A on the GLAD technique which has more than 200 citations to date.

Dr Michael T. Taschuk received his Ph.D. degree in electrical engineering from the University of Alberta in 2006 for his work developing the laser-induced breakdown spectroscopy technique. He has been working as a research associate at Alberta on GLAD since 2007, studying optical and sensor applications of GLAD thin films. He has published 33 peer-reviewed papers on the GLAD technique, as well as a book chapter covering GLAD theory and applications.

Dr Michael J. Brett is Canada Research Chair at the Department of Electrical and Computer Engineering at the University of Alberta, where he has taught since 1986. He also holds an appointment as Program Coordinator (Energy) at the National Institute for Nanotechnology. After commercialization success and worldwide sales of his microelectronics simulation software SIMBAD, his group developed and popularized the GLAD process in 1994, and their research has focused on this technique since that time, leading to over 190 journal papers and 5 patents that deal with GLAD and its applications. He is also the author of 4 book chapters and the acknowledged field leader in GLAD research.

Contenu

Series Preface xi

Preface xiii

1 Introduction: Glancing Angle Deposition Technology 1

1.1 Nanoscale engineering and glancing angle deposition 1

1.2 GLAD-vantages 4

1.2.1 Nanoscale morphology control 4

1.2.2 Broad material compatibility 6

1.2.3 Novel thin-film material properties 10

1.2.4 Compatibility with standard microfabrication processes 10

1.2.5 Scalable fabrication method 11

1.3 The roots of glancing angle deposition: oblique deposition 12

1.4 The importance of experimental calibration 13

1.5 Computer simulations of glancing angle deposition growth 15

1.6 Major application areas in glancing angle deposition technology 17

1.6.1 Energy and catalysis 17

1.6.2 Sensing applications 19

1.6.3 Optics 20

1.7 Summary and outline of the book 21

2 Engineering Film Microstructure with Glancing Angle Deposition 31

2.1 Introduction 31

2.2 Basics of conventional film growth 32

2.2.1 Physical vapour deposition 32

2.2.2 Nucleation and coalescence 33

2.2.3 Column microstructure 35

2.3 Glancing angle deposition technology: microstructural control via substrate motion 37

2.4 Engineering film morphology with 41

2.4.1 Controlling microstructure and porosity 41

2.4.2 Directional column growth: column tilt 44

2.5 Engineering film morphology: column steering via rotation 47

2.5.1 Controlling column architecture with : helical columns 47

2.5.2 Controlling microstructure with rotation speed: vertical columns 48

2.5.3 Continuous versus discrete substrate rotation 49

2.6 Growth characteristics of glancing angle deposition technology films 53

2.6.1 Evolutionary column growth 53

2.6.2 Column broadening 56

2.6.3 Column bifurcation 57

2.6.4 Anisotropic shadowing and column fanning 59

2.7 Advanced column steering algorithms 60

2.7.1 variations in zigzag microstructures 61

2.7.2 Spinpause/two-phase substrate rotation: decoupling and film density 63

2.7.3 Phisweep motion: competition-resilient structure growth 67

2.8 Additional control over film growth and structure 72

2.8.1 High-temperature glancing angle deposition growth 72

2.8.2 Multimaterial structures: co-deposition processes 75

3 Creating High-Uniformity Nanostructure Arrays 81

3.1 Introduction 81

3.2 Seed layer design 82

3.2.1 Seed spacing and seed height 84

3.2.2 Seed lattice geometry 86

3.2.3 Seed size 87

3.2.4 Planar fill fraction 89

3.2.5 Seed shape 90

3.2.6 Two-dimensional shadow coverage 91

3.2.7 Seed material 94

3.2.8 Design parameter summary 95

3.3 Seed fabrication 95

3.3.1 Conventional techniques 96

3.3.2 Unconventional techniques 97

3.4 Advanced control of local shadowing environment 99

3.4.1 Preventing bifurcation: slow-corner motion 99

3.4.2 Preventing broadening: phisweep and substrate swing 102

4 Properties and Characterization Methods 113

4.1 Introduction 113

4.2 Structural analysis with electron microscopy 113

4.2.1 Practical aspects 114

4.2.2 Scanning electron microscope image analysis 117

4.2.3 Three-dimensional column imaging: tomographic sectioning 122

4.2.4 Characterizing internal column structure with transmission electron microscope imaging 124

4.3 Structural properties of glancing angle deposition films 126

4.3.1 Film surface roughness and evolution 126

4.3.2 Column broadening 128

4.3.3 Intercolumn spacing and column density 133

4.4 Film density 134

4.4.1 Controlling density with : theoretical models 135

4.4.2 Experimental measurement and control of film density 136 4.5 Porosimetry and surface area determination 140</p&...