Nanoimprint Technology

Jun Taniguchi, Tokyo University of Science, Japan Jun Taniguchi is an Associate Professor in the Faculty of Industrial Science and Technology, at Tokyo University of Science in Japan. His research interests include electron beam lithography, nanoimprint lithography and nanotechnology. Hiroshi Ito, Yamagata University, Japan Hiroshi Ito is a Professor in the Department of Polymer Science and Engineering at Yamagata University in Japan. He is a board member for the Japan Society of Polymer Processing and Society Plastics Engineers. His major field of research is to clarify and control the development of high-order structure in polymeric materials through experimental and theoretical studies on polymer processing Jun Mizuno, Waseda University, Japan Jun Mizuno is an Associate Professor in the Nanotechnology Research Laboratory at Waseda University in Japan. His research interests include nanomaterials and intelligent mechanics. Takushi Saito, Tokyo Institute of Technology, Japan Takushi Saito is an Associate Professor in the Department of Mechanical and Control Engineering at Tokyo Institute of Technology in Japan. His research interests include polymer processing, laser assisted manufacturing and micro-scale processing

About of Editors ix

List of Contributors xi

Series Preface xiii

Preface xv

1 What is a Nanoimprint? 1

Jun Taniguchi

References 6

2 Nanoimprint Lithography: Background and Related Techniques 9

Hiroshi Ito(1) and Takushi Saito

2.1 History of Material Processing: Polymer Processing 9

2.2 Products with Microstructure and Nanostructure 11

2.3 Technology for Making Micro- and Nanostructures 12

References 15

3 Nanopattern Transfer Technology of Thermoplastic Materials 17

Takushi Saito and Hiroshi Ito(1)

3.1 Behavior of Thermoplastic Materials 17

3.1.1 Thermoplastics 17

3.1.2 Basis of Viscoelasticity and Rheology 19

3.1.3 Measurement of Rheology 20

3.1.4 Physical Properties of Viscoelastic Materials and the Temperature–Time Superposition Principle 21

3.1.5 Materials Design for Realizing Nanoimprints 24

3.2 Applicable Processes Used for Nanopattern Transfer 25

3.2.1 Introduction of Injection Molding Process 25

3.2.2 Problems of the Injection Molding Process 28

3.2.3 Advantages of the Thermal Imprinting Process 29

3.3 Pattern Transfer Mechanism of Thermal Cycle NIL 30

3.3.1 Introduction of Thermal Imprinting Process 30

3.3.2 In-situ Observation of Thermal Imprinting Process 32

3.3.3 Offline Measurement of Replication Process in Thermal Cycle NIL 35

3.4 Modeling of Nanopattern Transfer 38

3.4.1 Importance of Viscosity in Thermal Imprinting Process 38

3.4.2 Mathematical Treatment in Injection Molding and Thermal Imprinting Process 41

3.4.3 Process Simulation in Micro- and Nanopattern Transfer 44

References 48

Mold Fabrication Process 51

Mitsunori Kokubo, Gaku Suzuki, and Masao Otaki

4.1 Ultra Precision Cutting Techniques Applied to Metal Molds Fabrication for Nanoimprint Lithography 51

4.1.1 Introduction 51

4.1.2 Cutting of Fine Groove Shape 52

4.1.3 Method of Cutting Groove 53

4.1.4 Precision Cutting of Cylindrical Material 55

4.1.5 High-speed, Ultra Precision Machining System 56

4.1.6 Fine Pattern Processing by Bit Map Data 58

4.1.7 Machining of Dot Pattern Array 58

4.1.8 Improvement Points of the System 61

4.1.9 Summary 62

4.2 Nanoimprint Mold Fabrication Using Photomask Technology 62

4.2.1 Introduction 62

4.2.2 Summary of Mold Manufacturing Process 63

4.2.3 Pattern Writing Technique 67

4.2.4 Dry Etching 81

4.2.5 Examples of Fabricated Mold 85

4.2.6 Summary 89

5 Ultraviolet Nanoimprint Lithography 91

Jun Taniguchi, Noriyuki Unno, Hidetoshi Shinohara, Jun Mizuno, Hiroshi Goto, Nobuji Sakai, Kentaro Tsunozaki, Hiroto Miyake, Norio Yoshino, and Kenichi Kotaki

5.1 Orientation and Background of UV-NIL 91

5.2 Transfer Mechanism of UV-NIL 95

5.2.1 Viscosity and Capillary Force 96

5.2.2 Release Coating and Evaluation

of Release Properties 100

5.2.3 Release Coating Effect 103

5.3 UV-NIL Materials and Equipment 106

5.3.1 Ubiquitous NIL Machines 106

5.3.2 UV Nanoimprint Process Tool 110

5.3.3 UV-photocurable Resin 115

5.3.4 Fluorinated Polymers for UV-NIL 121

5.3.5 Cationic Curable Resins for UV-NIL 126

5.3.6 Molding Agents for Nanoimprinting 137

5.4 Evaluation Method 143

5.4.1 Macro Evaluation Technique of Nanoscale Pattern Shape and Evaluation Device 143

5.4.2 Characterization of Photocurable Resin for UV Nanoimprint 149

References 165

6 Applications and Leading-Edge Technology 169

Jun Taniguchi, Hidetoshi Shinohara, Jun Mizuno, Mitsunori Kokubo, Kazutoshi Yakemoto, and Hiroshi Ito(2)

6.1 Advanced Nanoimprinting Technologies 169

6.1.1 Resolution Limit of Nanoimprint Lithography 170

6.1.2 Improved Nanoimprinting Technologies 172

6.1.3 Roll-to-Roll Nanoimprinting Technologies 174

6.2 Applications 175

6.2.1 Seamless Pattern 175

6.2.2 Multistep Cu Interconnection 177

6.2.3 GaN Nanostructures for High-Intensity LED 182

6.3 High-Accuracy Nanoimprint Technology, Development of Micropatterning Method, and Automatic Process Control Using Batch Press Type, Step and Repeat Type Nanoimprint Machine 186

6.3.1 Introduction 186

6.3.2 Thermal Imprint 186

6.3.3 Summary 194

6.4 Micro/Nano Melt Transcription Molding Process 195

6.4.1 Outline of the Melt Transcription Molding Process 195

6.4.2 High Transcriptability 196

6.4.3 Excellent Optical Properties 200

6.4.4 Melt Transcription Molding System ‘‘MTM100-15’’ 201

Future Trends 202

References 203