ALTERNATIVE LITHOGRAPHY ALTERNATIVE LITHOGRAPHY Unleashing the Potentials of Nanotechnology Edited by Clivia M. Sotomayor Torres Institute of Materials Science and Department of Electrical & Information Engineering, University of Wuppertal, Germany Kluwer Academic Publishers Boston/Dordrecht/London Dedication This book is dedicated to Marfa, Oreste, Drina, Wolfgang and Samira Contents Dedication v Contributing Authors xiii Foreword xvii Preface xxi Acknowledgments xxiii Chapter 1. ALTERNATIVE LITHOGRAPHY 1 C. M. SOTOMAYOR TORRES.................................................... 1 1. Introduction..................................................................................... 1 2. Moulding polymers in the nanometer scale .................................... 3 3. Microcontact printing.................................................................... 11 4. Scanning probe aproaches............................................................. 12 5. Applications .................................................................................. 12 6. Recent nanofabrication experiments............................................ 13 7. Status and perspectives ................................................................. 13 viii Alternative Lithography Chapter 2. NANOIMPRINT LITHOGRAPHY 19 STEPHEN Y. CHOU................................................................. 19 1. Introduction................................................................................... 19 2. Nanoimprint lithography (NIL) Principle and process ................. 20 3. Resolution ..................................................................................... 21 4. 3-D patterning............................................................................... 23 5. Imprint over non-flat surfaces....................................................... 23 6. Uniformity and submicron alignment over 4 inch wafers............. 24 7. Different imprint machines ........................................................... 25 8. Applications .................................................................................. 28 9. Summary and future...................................................................... 28 Chapter 3. VISCOELASTIC PROPERTIES OF POLYMERS 31 THOMAS HOFFMANN ............................................................. 31 1. Introduction................................................................................... 31 2. Squeezing flow of a Newtonian liquid in HEL............................. 36 3. Viscoelastic properties of polymers.............................................. 46 4. Acknowledgements....................................................................... 54 Chapter 4. NANORHEOLOGY 57 HELMUT SCHIFT AND LAURA J. HEYDERMAN ...................... 57 1. Introduction................................................................................... 57 2. Basics of thin film rheology.......................................................... 62 3. Hot embossing in practice............................................................. 74 4. Looking ahead............................................................................... 88 Chapter 5. WATER SCALE NANOIMPRINT LITHOGRAPHY 95 LARS MONTELIUS AND BABAK HEIDARI .............................. 95 1. Introduction................................................................................... 95 2. Special requirements for large wafer scale NIL............................ 98 3. Fabrication of a nanoimprint lithography system ......................... 99 4. NIL Equipment design................................................................ 108 5. Imprint processing....................................................................... 112 6. Discussion and conclusions......................................................... 121 7. Acknowledgements..................................................................... 123 Alternative Lithography ix Chapter 6. STEP AND STAMP IMPRINT LITHOGRAPHY 127 JOUNI AHOPELTO AND TOMI HAATAINEN........................... 127 1. Introduction................................................................................. 127 2. Step and stamp imprinting lithography....................................... 129 3. Pattern transfer using step and stamp imprint lithography.......... 133 4. Mix and match with UV lithography .......................................... 135 5. Pattern reproduction.................................................................... 137 6. Conclusions................................................................................. 140 Acknowledgements .......................................................................... 141 References........................................................................................ 141 Chapter 7. STEP AND FLASH IMPRINT LITHOGRAPHY 143 T.C. BAILEY, M. COLBURN, B.J. CHOI, A. GROT, J.G. EKERDT, S.V. SREENIVASAN, C.G. WILLSON ............. 143 1. Introduction................................................................................. 143 2. Process overview......................................................................... 145 3. Template fabrication ................................................................... 146 4. Surface treatment ........................................................................ 148 5. Etch barrier.................................................................................. 150 6. Reliability.................................................................................... 159 7. Patterning results......................................................................... 162 Chapter 8. USING PDMS AS A THERMOCURABLE RESIST FOR A MOLD ASSISTED IMPRINT PROCESS 169 L. MALAQUIN, C. VIEU ....................................................... 169 1. Introduction................................................................................. 170 2. PDMS material............................................................................ 171 3. Technological implementation.................................................... 176 4. Results......................................................................................... 184 5. Conclusions and domains of application..................................... 199 Chapter 9. MOLECULES FOR MICROCONTACT PRINTING 205 JURRIAAN HUSKENS, MAIK LIEBAU AND DAVID N. REINHOUDT ........................................................ 205 1. Introduction................................................................................. 205 2. Quality of printed SAMs............................................................. 207 x Alternative Lithography 3. Microcontact printing of etch resists........................................... 210 4. Printing functional adsorbates..................................................... 213 5. Printing on other substrates......................................................... 214 6. Microcontact printing in bio-applications................................... 216 7. Conclusions................................................................................. 218 Chapter 10. MICROCONTACT PRINTING TECHNIQUES 223 MASSIMO TORMEN .............................................................. 223 1. Introduction................................................................................. 223 2. The self-assembly of alkanethiols............................................... 226 3. The stamp.................................................................................... 228 4. Properties of poly(dimethyl siloxane) elastomers....................... 229 5. Stamps for microcontact printing................................................ 235 6. Stamp fabrication........................................................................ 238 7. The microcontact printing process.............................................. 239 8. Substrates for microcontact printing ........................................... 240 9. Printing conditions...................................................................... 243 10. Chemical etching......................................................................... 244 11. Microcontact printing using ultrathin stamps ............................. 246 12. A multilevel process: Mix and Match with accurate alignment of the µCP .................................................................. 257 13. Conclusions................................................................................. 259 14. Acknowledgements..................................................................... 259 Chapter 11. LOCAL OXIDATION NANOLITHOGRAPHY 265 RICARDO GARCIA................................................................ 265 1. Introduction................................................................................. 265 2. Local oxidation modes ................................................................ 267 3. Liquid meniscus .......................................................................... 271 4. Kinetics ....................................................................................... 274 5. Mechanism.................................................................................. 276 6. Substrates .................................................................................... 277 7. Resolution ................................................................................... 278 8. Applications ................................................................................ 280 9. Summary ....................................................................................