Nano Science and Technology: Novel Structures and Phenomena Edited by Zikang Tang and Ping Sheng Hong Kong University of Science and Technology Clear Water Bay, Hong Kong © 2003 Zikang Tang and Ping Sheng/CRC Press LLC First published 2003 by Taylor & Francis 11 New Fetter Lane, London EC4P 4EE Simultaneously published in the USA and Canada by Taylor & Francis Inc, 29 West 35th Street, New York, NY 10001 Taylor & Francis is an imprint of the Taylor & Francis Group © 2003 Zikang Tang and Ping Sheng Printer’s Note: This book was prepared from camera-ready-copy supplied by the authors Printed and bound in Great Britain by TJ International, Padstow, Cornwall All rights reserved. No part of this book may be reprinted or reproduced or utilised in any form or by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying and recording, or in any information storage or retrieval system, without permission in writing from the publishers. Every effort has been made to ensure that the advice and information in this book is true and accurate at the time of going to press. However, neither the publisher nor the authors can accept any legal responsibility or liability for any errors or omissions that may be made. In the case of drug administration, any medical procedure or the use of technical equipment mentioned within this book, you are strongly advised to consult the manufacturer’s guidelines. British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Library of Congress Cataloging in Publication Data Croucher ASI on Nano Science and Technology (2nd : Hong Kong University of Science and Technology) Nano science and technology : novel structures and phenomena / edited by Zikang Tang and Ping Sheng. p. cm. Proceedings of the second Croucher ASI on Nano Science and Technology, held at the Hong Kong University of Science and Technology Includes bibliographical references and index. ISBN 0–415–30832–1 (hb) 1. Nanostructure materials—Congresses. 2. Nanotechnology—Congresses. I. Tang, Zikang, 1959– II. Sheng, Ping, 1946– III. Title. TA418.9.N35 C76 2003 620′.5—dc21 2002075066 ISBN 0–415–30832–1 © 2003 Zikang Tang and Ping Sheng/CRC Press LLC Contents Preface Part 1 NOVEL NANOSTRUCTURES AND DEVICES 1 Nanopatterning with Diblock Copolymers 2 P. M. Chaikin, C. Harrison, M. Park, R. A. Register, D. H. Adamson, D. A. Huse, M. A. Trawick, R. Li and P. Dapkus Nanostructured Materials: Basic Concepts, Microstructure 3 and Properties H. Gleiter Tuning the Electronic Structure of Solids by Means of 4 Nanometer-sized Microstructures H. Gleiter Epitaxial Growth and Electronic Structure of Self-assembled 5 Quantum Dots P. M. Petroff Self Assembled Quantum Dot Devices 6 P. M. Petroff Solvothermal Synthesis of Non-oxides Nanomaterials 7 Y. T. Qian Nanostructures at Solid/Liquid Interface 8 L. J. Wan and C. L. Bai Fabrication, Characterization and Physical Properties of 9 Nanostructured Metal Replicated Membranes Y. Lei, W. Cai and L. Zhang Vesicular and Tubular Nanoassemblies of an Helical 10 Amphiphilic Polyacetylene B. S. Li, K. K. L. Cheuk, J. Chen, X. Xiao, C. Bai and B. Z. Tang Evolution of Two-Dimensional Nanoclusters on Surfaces Part 2 11 W. W. Pai and D. 4. Liu FULLERENES AND NANOTUBES Exploring the Concave Nanospace of Fullerenic Material H. Kuzmany, R. Pfeiffer, T. Pichler, Ch. Kramberger, M. Krause and X. Liu © 2003 Zikang Tang and Ping Sheng/CRC Press LLC 12 Controlled Synthesis of Carbon Nanotubes and their Field 13 Emission Properties S. Fan, L. Liu, Z Yuan and L. Sheng Superconductivity in 4-Angstrom Carbon Nanotubes 14 P. Sheng, Z K. Tang, L. Zhang, N. Wang, X. Zhang, G. H. Wen, G. D. Li, J. Wang and C. T. Chan Ultra-small Single-walled Carbon Nanotubes and their Novel 15 Properties Z K. Tang, L L Li, Z M. Li, N. Wang and P. Sheng Free Radical Attack on C. Embedded in Nanochannels of 16 Mesoporous Silica C. H. Lee, H. P. Lin, T. S. Lin and C. Y Mou Template-directed Synthesis of Carbon Nanotube Array by 17 Microwave Plasma Chemical Reaction at Low Temperature Q. Wu, Z. Hu, X. Z Wang, X. Chen and Y Chen Field Emission Enhancement of Multiwalled Carbon Nanotubes Film by Thermal Treatment under UHV and in Hydrogen and Ethylene Atmospheres L. Stobinski, C. S. Chang, H. M. Lin and T T. Tsong Part 3 NANOCOMPOSITES AND SEMICONDUCTOR NANOSTRUCTURES 18 Micro-domain Engineering for Optics and Acoustics 19 S. N. Zhu, Y.Y. Zhu and N.B. Ming Distinguishing Spinodal and Nucleation Phase Separation in 20 Dewetting Polymer Films 0. K. C. Tsui, B. Du, F. Xie, Y. J. Wang, H. Yan and Z. Yang Fabrication of Mesoscopic Devices using Atomic Force 21 Microscopic Electric Field Induced Oxidation F. K. Lee, G. H. Wen, X. X. Zhang and 0. K. C. Tsui Copper Nanowires Prepared by the Treatment of the Cu 2 S 22 Nanowires in a Radio-frequency Hydrogen Plasma S. Wang, X. Wen and S. Yang The Viscoelastic Effect on the Formation of Mesoglobular Phase 23 of Dilute Heteropolymer Solutions Chi Wu Chemical Coating of the Metal Oxides onto Mesoporous Silicas H.P. Lin, Y.H. Liu and C.Y. Mou © 2003 Zikang Tang and Ping Sheng/CRC Press LLC 24 Emission in Wide Band Gap II-VI Semiconductor Compounds 25 with Low Dimensional Structure X. W. Fan, G. Y. Yu, Y. Yang, D. Z Shen, J. Y Zhang, Y C. Liu and Y. M. Lu Temperature and Magnetic Field Dependent Transports in 26 Granular Structures H. Y. Cheung, T. K. Ng and P. M. Hui Mechanism and Method of Single Atom Pyramidal Tip Formation 27 from a Pd Covered W Tip T. Y. Fu and T. T. Tsong Hydrogen and Proton Transport Properties of Nanoporous Zeolite Micromembranes J. L. H. Chau, A. Y. L. Leung, M. B. Shing, K. L. Yeung and C. M. Chan Part 4 THEORY AND SIMULATIONS 28 Alkali Intercalation of Ultra-Small Radius Carbon Nanotubes 29 H. J. Liu, J. L. Yang and C. T. Chan Engineering Acoustic Band Gaps in Phononic Crystals 30 Z. Q. Zhang, Y. Lai and X. Zhang Quantum Dynamics of Coupled Quantum-Dot Qubits and 31 Dephasing Effects Induced by Detections Z. T. Jiang, J. Peng, J. Q. You, S. S. Li and H. Z Zheng Coherent Dynamics and Quantum Information Processing in Josephson Charge Devices J. Q. You, F. Nori and J. S. Tsai © 2003 Zikang Tang and Ping Sheng/CRC Press LLC © 2003 Zikang Tang and Ping Sheng/CRC Press LLC Preface This volume represents the proceedings of the second Croucher ASI on Nano Science and Technology held at HKUST. The first one was exactly three years ago. This ASI invited six plenary speakers. They not only delineated the cutting edge of research in nano science and technology, but in the process also "wowed" the audience and created a stir. Prof. Donald Eigler and Prof. Kunio Takayanagi were especially impressive in showing pictures and videos of atomic manipulations, creating novel functionalities at the nanometer scale. Their talks opened listeners' eyes to the future potential of nanotechnology, and brought quantum mechanics, formerly a somewhat abstract topic, to a direct visual level. Prof. Steve Louie showed that the greatly increased predictive power of theory and simulation has brought us a step closer to the holy grail of "material-by-design," whereby the material properties can be predicted and their associated structures specified as recipes for fabrication. Prof. Paul Chaiken and Prof. Pierre Petroff showed two orthogonal approaches to the fabrication of semiconductor quantum dots (artificial atoms), and their potentials to optical and electronic technologies. Prof. Herbert Gleiter, a pioneer in nanoscience and nanotechnology, delineated the direction of nanotechnology in traditional disciplines such as metallurgy. Complementing the plenary talks were the excellent invited talks by both local, Chinese mainland, and Taiwan speakers. The talks gave a snapshot of the best works done in this region over the past two years, and showed the great progress that has been achieved recently in nanoscience and nanotechnology in this region. From the responses of the participants, it is clear that the topic of nanoscience and nanotechnology has captured a resonance of our times. During the discussion sessions of the ASI, there were lively debates on the nature of this "nano phenomenon" and where it is leading us. From our personal observations at the level of working scientists, it is clear that the primary driving force for the nano phenomenon comes from the scientific possibilities that arise due to the confluence of advances in characterization, measurements, and computation. Research fundings are the consequence, rather than the cause, of this manifest "destiny." Hence the nano phenomenon represents a historical trend, starting from thousands of years ago with the human mastery of kilometre-scale technology (e.g., Egyptian © 2003 Zikang Tang and Ping Sheng/CRC Press LLC Preface Pyramids, the Chinese Great Wall), to the millimetre-scale technology (e.g., watches) a few hundred years ago, to the micrometre-scale technology (e.g., microelectronics) of the twentieth century, to the present development of the nanometre-scale technology platform. Once the nanotechnology platform is established, perhaps ten to twenty years from now, there is no doubt that another revolution in human lives would occur. It is our hope that the present volume can capture the spirit of this Croucher ASI and give readers one cross sectional view of the rapidly evolving nano science and technology. Zikang Tang and Ping Sheng Hong Kong University of Science & Technology Clear Water Bay, Hong Kong May, 2002 Part 1 NOVEL NANOSTRUCTURES AND DEVICES © 2003 Zikang Tang and Ping Sheng/CRC Press LLC 1 Nanopatterning with DiblockCopolymers P. M. Chaikin'' 2 , C. Harrison', M. Park', R. A. Register 2 ' 3 , D. H. Adamson 2 , D. A. Huse', M. A. Trawick', R. Li 4 and P. Dapkus 4 ' Department of Physics, P Princeton Materials Institute, 3 Department of Chemical Engineering, Princeton University, Princeton, New Jersey 08544, Compound Semiconductor Laboratory, Department of Electrical Engineering/ Electrophysics, University of Southern California, Los Angeles, CA 90089 1.1 INTRODUCTION There has been an interest in going beyond conventional lithographic techniques in order to make features of ever smaller scale and higher density over large areas. In this paper we discuss progress that has been made over the past decade in using the self-assembly of diblock copolymer films as a template for creating two dimensional patterns (lines and dots) with a characteristic spacing of 20-30 nm. Typically trillions of dots, holes, posts of semiconductors and metals are produced on conventional semiconductor wafers. We describe the basic concept of the pattern formation and the technology of the transfer of the pattern from soft to hard materials. In order to produce and study these nanoscopic patterns we had to develop some new techniques for getting two and three dimensional images. 3D depth profiling with reactive ion etch (RIE) slices of 7 nm thickness alternating with electron microscope pictures proved very effective. We became very interested in the pattern formation and annealing necessary to control the long range order of the arrays and found new ways to follow the ordering. The coarsening was found to obey a t" 4 power law, (that is the size of the "grains" grew with time with this dependence) and at least for the striped pattern (cylinders lying down in a fingerprint like pattern) we could understand the microscopic origin of this behavior. We studied these phenomena with time lapse AFM microscopy and found that the disorder was dominated by the presence of disclinations and the annealing occurred by the annihilation of disclination multipoles rather than simple disclination - antidisclination, dipole dynamics. We also found that the orientation of the patterns could be controlled by introducing alignment marks, step edges. © 2003 Zikang Tang and Ping Sheng/CRC Press LLC 4 Chaikin et al. 1.1.1 Why Nanolithography? Our interest in periodic patterns on the nanometer scale originated in a physics problem, the Hofstadter (1976) "butterfly", a problem of incommensurability between a periodic potential and flux quantization in a magnetic field. The competition of lengths-scales leads to a fascinating fractal energy spectrum. The best way to observe these effects is to take a quantum Hall device in the lowest Landau level and decorate it with a periodic potential on the scale of the cyclotron radius (Thouless, 1982). For a magnetic field of 1 Tesla the characteristic magnetic length, 1, which gives a flux quanta (4o he/e) through its area (H1 2 = O o ) is 1-20 nm. We therefore wanted to create a two dimensional lattice with unit cells on this scale and transfer a potential from this pattern to the two dimensional electron gas that resides about 20 nm below the surface of a quantum Hall device. Lithographic techniques are constantly evolving and the feature size is getting smaller. Presently large scale integrated devices (like Pentium chips) are produced by optical lithography with feature size >150 nm. Smaller features are readily produced by electron beam lithography, down to >25 nm, but it is difficult to place such features next to one another at the same scale and to produce periodic arrays of them. Moreover it is extremely time consuming to cover large areas with such patterns if each must be separately written, even once. Aside from the Hofstadter spectrum such dense periodic arrays should have interest for magnetic disk drives, for addressable memories, as optical elements, for quantum dots, for excitation and transfer between dye molecules and in biology as filters and sensors for proteins and nucleic acid sections. In many of these applications, e.g. filters, disks drives, quantum dots, it is the size and density that are of interest, while in other applications the periodicity and long range order are required. Our interest in using diblock copolymers for this work was initiated in discussions with Dr. Lew Fetters who had studied the synthesis and three dimensional structure of different diblock copolymer phases (Morton, 1975). The cross sections of his samples showed beautiful lattices with spacings on the 20 nm scale and perfect order over many microns. The idea of transferring these patterns to other organic and inorganic substrates was attractive since the copolymer self- assembly could be done over large scales simultaneously, the morphology and length scale were chemically modifiable and the materials were fairly easy to work with. The basic physical and chemical properties of the diblock copolymers were already a well developed science in the bulk and they could be readily processed by techniques used in conventional semiconducting lithography. The fact that nanoscale patterns remained suitable in thin films was demonstrated by Mansky et al. (Mansky, 1995, 1996). © 2003 Zikang Tang and Ping Sheng/CRC Press LLC [...]... Ehrichs E E., Jaeger H M., Mansky P and Russell T P., 1996, Science 273, 931 Morton M and Fetters L J., 1975, Rubber Chem Technol 48, 359 © 2003 Zikang Tang and Ping Sheng/ CRC Press LLC 24 Chaikin et al Park M., Chaikin P M., Register R A and Adamson D H., 2001, Appl Phys Lett 79, 25 7-2 59 Park Miri, Harrison C., Chaikin P M., Register R A and Adamson D H., 1997a, Science 276, 1401 Park M., Harrison... materials, nanocrystalline materials or supramolecular solids In this paper we shall focus on these "Nanostructured Materials" (NsM) © 2003 Zikang Tang and Ping Sheng/ CRC Press LLC Figure 1 Schematic, two dimensional model of one kind of nanocrystalline material Figure 2 Synthesis of nanomaterials with different chemical microstructures by the consolidation of small, pre-fabricated, isolated nm-sized crystal... generation of glasses or sols Figure 3 Synthesis of a nanocrystalline material (right figure) by crystallization from the glass (left) © 2003 Zikang Tang and Ping Sheng/ CRC Press LLC 30 Gleiter 3.2.2 Self-organized 1 nanostructured arrays A modified Stranski-Krastanov growth mechanism has been noticed to result in self-organized (periodic) arrays of nanometer-sized crystallites If a thin InGaAs layer is grown... Chemistry (Cornell University Press, 1953), Ch XII Hahm J., Lopes W A., Jaeger H M and Sibener S J., 1998, J Chem Phys 109, 10111 Harrison C., Park M., Chaikin P., Register R A., Adamson D H and Yao N., 1998a, Macromolecules 31, 2185 Harrison C., Park M., Chaikin P M., Register R A., Adamson D H and Yao N., 1998b, Polymer 39, 273 3-2 744 © 2003 Zikang Tang and Ping Sheng/ CRC Press LLC Nanopatterning with Diblock... Plastic H poly(styrene) - H CH, I H - H H H -c-c=c-c- -c-c=c-c- 1,4 polylisuprcne) 1,4 peIy(buFadicne) e.g H k l H H_ H • polpsLyrenc-r.i i,opiz Jl e rl ~~~ I ~ PS m ~ H H- Rubbers I1 CIµ H JO I 'I Figure 3 The diblocks we use are usually a plastic and a rubber as in the monomers and diblock shown here The polymers that we used were generally a plastic (such as polystyrene) and a rubber (such as polybutadiene... Nightingale M P and den Nijs M., 1982, Phys Rev Lett 49, 405 Volkmuth W D., Duke T., Wu M C., Austin R H and Szabo A., 1994, Phys Rev Lett 72, 2117 Yurke B., Pargellis A N., Kovacs T and Huse D A., 1993, Phys Rev E 47, 1525 © 2003 Zikang Tang and Ping Sheng/ CRC Press LLC 2 Nanostructured Materials: Basic Concepts, Microstructure and Properties H Gleiter Forschungszentrum Karlsruhe, Institut fur Nanotechnologie,... in place of © 2003 Zikang Tang and Ping Sheng/ CRC Press LLC Nanopatterning with Diblock Copolymers 11 PS-Red Patterned Silicon Nitride Figure 6 SEM images of mask and transferred pattern PB and a different thickness of PS between the air and the substrate to be patterned As illustrated in figure 5 a CF, etch can now transfer the pattern into the substrate Since the etch rates of PS and Si are comparable,... density and correlation length as a function of time are shown in figure 15 While the Figure 15 Top - human fingerprint with loop and triradius, corresponding to the topological defects: left) +1/2 disclination and right) -1 /2 disclination © 2003 Zikang Tang and Ping Sheng/ CRC Press LLC 18 Chaikin et al correlation length indeed seems to remain the distance between disclinations t"4 2 (p « ~ ) and they... spontaneous emergence of order in either space and/ or time and also includes dissipative structures such as nonlinear chemical processes, energy flow, etc Systems are called self-assembled in the spontaneously created structure is in equilibrium (Landauer, 1987; Haken, 1978 and 1994; Nocolis and Prigogine, 1977) I © 2003 Zikang Tang and Ping Sheng/ CRC Press LLC ... The free surfaces of the nm-sized crystals are coated with atoms that differ chemically from the core resulting in a NsM with boundaries that are chemically different from the crystalline regions open and full circles (c) Nm-sized crystals with different chemical compositions resulting in a nanocomposit © 2003 Zikang Tang and Ping Sheng/ CRC Press LLC 28 Gleiter 3 SYNTHESIS OF NANOSTRUCTURED MATERIALS . Nano Science and Technology: Novel Structures and Phenomena Edited by Zikang Tang and Ping Sheng Hong Kong University of Science and Technology Clear Water Bay, Hong Kong © 2003 Zikang Tang and. ASI on Nano Science and Technology (2nd : Hong Kong University of Science and Technology) Nano science and technology : novel structures and phenomena / edited by Zikang Tang and Ping Sheng. p Nori and J. S. Tsai © 2003 Zikang Tang and Ping Sheng/ CRC Press LLC © 2003 Zikang Tang and Ping Sheng/ CRC Press LLC Preface This volume represents the proceedings of the second Croucher ASI on Nano Science