DOCSLIB.ORG

The Pennsylvania State University

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Pennsylvania State University The Pennsylvania State University The Graduate School SYNTHESIS AND CHARACTERIZATION OF TWO-DIMENSIONAL MATERIALS FOR BEYOND COMPLEMENTARY METAL OXIDE SEMICONDUCTOR TECHNOLOGY A Dissertation in Materials Science and Engineering by Rui Zhao © 2019 Rui Zhao Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy August 2019 ii The dissertation of Rui Zhao was reviewed and approved* by the following: Joshua A. Robinson Associate Professor of Materials Science and Engineering Dissertation Advisor Chair of Committee Mauricio Terrones Distinguished Professor of Physics, Chemistry, and Materials Science and Engineering Roman Engel-Herbert Associate Professor of Materials Science and Engineering, Chemistry and Physics Saptarshi Das Assistant Professor of Engineering, Science & Mechanics John Mauro Professor of Materials Science and Engineering Chair, Intercollege Graduate Degree Program Associate Head for Graduate Education, Materials Science and Engineering *Signatures are on file in the Graduate School iii ABSTRACT Rapid development in Semiconductor research has brought excitement and challenges. New materials have pushed both academic and industry progress forward at a fast pace. Since the discovery of one-atomic layer of graphene in 2004, tremendous efforts have been devoted to pushing its properties to meet the technology demands, establish metrics and help accomplish milestones. The family of two-dimensional materials continue to expand. Transition metal dichalcogenides (TMDs) help compensate for the zero-bandgap of graphene and greatly increase the opportunities for their applications in electronics, optoelectronics, bioelectronics and medical- related applications. To enable electronic chips with higher density and faster processing/switching speeds and address technology bottlenecks, new correlated or functionalized two-dimensional materials are being positioned under the research spotlight. As one example, 1T phase tantalum disulfide (1T- TaS2) has presented a Mott state at around 180K, at which an abrupt change in its resistivity occurs. This unique property could help achieve two-dimensional Landau switch and realize ultra-low power, collective-state devices. However, large-scale synthesis of single crystalline monolayer of two-dimensional materials is still at its infancy. Fundamental questions as to the structural-property relationships of new materials or heterostructures await to be addressed. This dissertation focuses on the synthesis and characterizations of functional two-dimensional nanomaterials for beyond complementary metal oxide semiconductor industry. This dissertation starts with introducing the state of art of semiconductor industries and the progress of two-dimensional transition metal dichalcogenides (Chapter 1). It then addresses the two-dimensional materials’ synthesis methods and related characterization techniques (Chapter 2). Precursor selections and precursor-substrate interactions are discussed in Chapter 3. Then two specific nanomaterials are specially addressed in the next three chapters. Chapter 4 includes iv dissertation research work on synthesizing and characterization of pristine 1T-TaS2 while chapter 5 focus its functionalization and address the potential application and challenges. Chapter 6 is concentrated on 2H-MoS2 and evaluate its potentials in copper diffusion barriers. Chapter 7 provides a summary for all my research work and concludes this dissertation. v TABLE OF CONTENTS LIST OF FIGURES ................................................................................................................. vii LIST OF TABLES ................................................................................................................... xviii ACKNOWLEDGEMENTS ..................................................................................................... xix Chapter 1 Introduction ............................................................................................................ 1 1-1 Overview of semiconductor industry ......................................................................... 1 1-2 Overview of two-dimensional transition metal dichalcogenides (TMDs) ................. 4 1.2.1 Structures of TMDs ......................................................................................... 5 1.2.2 Band structures of TMDs ................................................................................ 7 1.2.3 Charge density waves (CDWs) ....................................................................... 8 1-3 Overview of chemical functionalization of TMDs .................................................... 9 1.3.1 Doping of TMDs ............................................................................................. 10 1.3.2 Intercalation of TMDs ..................................................................................... 11 1.3.3 Alloying of TMDs ........................................................................................... 14 1-4 Overview of heterostructures based on TMDs .......................................................... 15 Chapter 2 Thin film characterizatons and device measurements ............................................ 18 2-1 The synthesis “Atlas” ................................................................................................ 18 2-2 Epitaxial thin films .................................................................................................... 22 2-3 The synthesis “Atlas” for two-dimensional (2D) materials ....................................... 24 2-4 Thin film characterizations ........................................................................................ 27 2-4-1 Raman spectroscopy and Photoluminescence ................................................ 27 2-4-2 Scanning electron microscopy and energy-dispersive X-ray spectroscopy .... 30 2-4-3 Scanning force microscopy ............................................................................ 32 2-4-4 X-ray photoelectron spectroscopy .................................................................. 35 2-4-5 Transmission electron microscopy ................................................................. 37 2-5 Basics of field effect transistors (FET) ...................................................................... 39 2-5-1 Field effect transistors .................................................................................... 39 2-5-2 Device fabrication ........................................................................................... 41 2-5-3 Device measurements ..................................................................................... 46 Chapter 3 Precursor and substrate interactions ....................................................................... 49 3-1 Introduction to precursor selections ........................................................................... 49 3-2 Growth assistance agents ........................................................................................... 51 3-3 The impact of chalcogenide precursors on growth substrate: a study of Si-S-Te ternary phase diagram .............................................................................................. 57 3-4 Synthesis and characterization of ultra-thin-silica (UTS) .......................................... 60 Chapter 4 1T-Tantalum Disulfide (1T-TaS2) .......................................................................... 62 vi 4-1 State of the art of 1T-TaS2 ......................................................................................... 63 4-2 Synthesis of 1T-TaS2 ................................................................................................. 68 4-3 Raman spectroscopy of 1T-TaS2 CDW structures ..................................................... 72 4-4 Substrate impacts on 1T-TaS2 phase transitions ........................................................ 74 Chapter 5 Functionalization of 1T-TaS2 ................................................................................. 81 5-1 Doping of 1T-TaS2..................................................................................................... 81 5-2 Intercalation of 1T-TaS2 ............................................................................................ 85 5-3 Heterostructure construction of 1T-TaS2 and MoS2 .................................................. 92 Chapter 6 2H-Molybdenum Disulfide .................................................................................... 99 6-1 Synthesis and characterization of 2H-MoS2 .............................................................. 99 6-2 Nb-doping of 2H-MoS2 ............................................................................................. 103 6-3 Nb-doping of MoS2 as copper diffusion barrier ........................................................ 107 Chapter 7 Dissertation summary ............................................................................................. 111 Reference ................................................................................................................................. 114 vii LIST OF FIGURES Figure 1-1: (a) The supply and demand in the semiconductor device. (b) The market continues to drive integrated system towards more diversified (More than Moore) and more minimized (More Moore). Both figures are retrieved from reference 22. ............... 2 Figure 1-2: (a) A diagram aims to address the domains and subdomains of Internet of Things (IoT).
Load more

Recommended publications
  • Single Crystalline 2D Layers with Linear Magnetoresistance and High C
    pubs.acs.org/cm Article Thickness-Controlled Synthesis of CoX2 (X = S, Se, and Te) Single Crystalline 2D Layers with Linear Magnetoresistance and High Conductivity Xingguo Wang, Zhang Zhou, Peng Zhang, Shuqing Zhang, Yang Ma, Weiwei Yang, Hao Wang, Bixuan Li, Lingjia Meng, Huaning Jiang, Shiqiang Cui, Pengbo Zhai, Jing Xiao, Wei Liu, Xiaolong Zou, Lihong Bao,* and Yongji Gong* Cite This: Chem. Mater. 2020, 32, 2321−2329 Read Online ACCESS Metrics & More Article Recommendations *sı Supporting Information ABSTRACT: Two-dimensional (2D) materials especially transition metal dichalcogenides (TMDs) have drawn intensive interest owing to their plentiful properties. Some TMDs with magnetic elements (Fe, Co, Ni, etc.) are reported to be magnetic theoretically and experimentally, which undoubtedly provide a promising platform to design functional devices and study physical mechanisms. Nevertheless, plenty of theoretical TMDs remain unrealized experimentally. In addition, the governable synthesis of these kinds of TMDs with desired thickness and high crystallinity poses a tricky challenge. Here, we report a controlled preparation of CoX2 (X = S, Se, and Te) nanosheets through chemical vapor deposition. The thickness, lateral scale, and shape of the crystals show great dependence on temperature, and the thickness can be controlled from a monolayer to tens of nanometers. Magneto-transport characterization and density function theory simulation indicate that CoSe2 and CoTe2 are metallic. In addition, unsaturated and linear magnetoresistance have been × 6 × 6 observed even up to 9 T. The conductivity of CoSe2 and CoTe2 can reach 5 10 and 1.8 10 S/m, respectively, which is pretty high and even comparable with silver. These cobalt-based TMDs show great potential to work as 2D conductors and also provide a promising platform for investigating their magnetic properties.
    [Show full text]
  • Polytypism, Polymorphism, and Superconductivity in Tase2−Xtex
    Polytypism, polymorphism, and superconductivity in TaSe2−xTex Huixia Luoa,1, Weiwei Xiea, Jing Taob, Hiroyuki Inouec, András Gyenisc, Jason W. Krizana, Ali Yazdanic, Yimei Zhub, and Robert Joseph Cavaa,1 aDepartment of Chemistry and cJoseph Henry Laboratories and Department of Physics, Princeton University, Princeton, NJ 08544; and bDepartment of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, NY 11973 Contributed by Robert Joseph Cava, February 9, 2015 (sent for review January 14, 2015; reviewed by J. Paul Attfield and Maw-Kuen Wu) Polymorphism in materials often leads to significantly different 3R form (20–22). The 3R form can be synthesized, but it is not the physical properties—the rutile and anatase polymorphs of TiO2 are stable variant (the 2H form is) and so has been the subject of little a prime example. Polytypism is a special type of polymorphism, study. In one of the other polymorphs, the 1T (T: trigonal) type, occurring in layered materials when the geometry of a repeating Ta is found in octahedral coordination in the Se-Ta-Se layers and structural layer is maintained but the layer-stacking sequence of the layer stacking along the c axis of the trigonal cell such that the the overall crystal structure can be varied; SiC is an example of structure repeats after only one layer (23) (Fig. 1A). Again, the 1T a material with many polytypes. Although polymorphs can have form has not been the subject of much study. Here we show that radically different physical properties, it is much rarer for polytyp- the 3R and 1T polymorphs are both quite stable in the TaSe2−xTex ism to impact physical properties in a dramatic fashion.
    [Show full text]
  • New Minerals Approved Bythe Ima Commission on New
    NEW MINERALS APPROVED BY THE IMA COMMISSION ON NEW MINERALS AND MINERAL NAMES ALLABOGDANITE, (Fe,Ni)l Allabogdanite, a mineral dimorphous with barringerite, was discovered in the Onello iron meteorite (Ni-rich ataxite) found in 1997 in the alluvium of the Bol'shoy Dolguchan River, a tributary of the Onello River, Aldan River basin, South Yakutia (Republic of Sakha- Yakutia), Russia. The mineral occurs as light straw-yellow, with strong metallic luster, lamellar crystals up to 0.0 I x 0.1 x 0.4 rnrn, typically twinned, in plessite. Associated minerals are nickel phosphide, schreibersite, awaruite and graphite (Britvin e.a., 2002b). Name: in honour of Alia Nikolaevna BOG DAN OVA (1947-2004), Russian crys- tallographer, for her contribution to the study of new minerals; Geological Institute of Kola Science Center of Russian Academy of Sciences, Apatity. fMA No.: 2000-038. TS: PU 1/18632. ALLOCHALCOSELITE, Cu+Cu~+PbOZ(Se03)P5 Allochalcoselite was found in the fumarole products of the Second cinder cone, Northern Breakthrought of the Tolbachik Main Fracture Eruption (1975-1976), Tolbachik Volcano, Kamchatka, Russia. It occurs as transparent dark brown pris- matic crystals up to 0.1 mm long. Associated minerals are cotunnite, sofiite, ilin- skite, georgbokiite and burn site (Vergasova e.a., 2005). Name: for the chemical composition: presence of selenium and different oxidation states of copper, from the Greek aA.Ao~(different) and xaAxo~ (copper). fMA No.: 2004-025. TS: no reliable information. ALSAKHAROVITE-Zn, NaSrKZn(Ti,Nb)JSi401ZJz(0,OH)4·7HzO photo 1 Labuntsovite group Alsakharovite-Zn was discovered in the Pegmatite #45, Lepkhe-Nel'm MI.
    [Show full text]
  • LTS Research Laboratories, Inc. Safety Data Sheet Rhenium Sulfide ––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– 1
    LTS Research Laboratories, Inc. Safety Data Sheet Rhenium Sulfide ––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– 1. Product and Company Identification ––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– Trade Name: Rhenium Sulfide Chemical Formula: ReS2 Recommended Use: Scientific research and development Manufacturer/Supplier: LTS Research Laboratories, Inc. Street: 37 Ramland Road City: Orangeburg State: New York Zip Code: 10962 Country: USA Tel #: 855-587-2436 / 855-lts-chem 24-Hour Emergency Contact: 800-424-9300 (US & Canada) +1-703-527-3887 (International) ––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– 2. Hazards Identification ––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– Signal Word: None Hazard Statements: None Precautionary Statements: None HMIS Health Ratings (0-4): Health: 1 Flammability: 0 Physical: 1 ––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– 3. Composition ––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– Chemical Family: Ceramic Additional Names: Rhenium (IV) sulfide, Rhenium disulfide Rhenium Sulfide (ReS2): Percentage: 100 wt% CAS #: 12038-63-0 EC #: 234-873-3 ––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– 4. First Aid Procedures –––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––
    [Show full text]
  • The Relations Between Van Der Waals and Covalent Forces in Layered Crystals
    This document is downloaded from DR‑NTU (https://dr.ntu.edu.sg) Nanyang Technological University, Singapore. The relations between Van Der Waals and covalent forces in layered crystals Chaturvedi, Apoorva 2017 Chaturvedi, A. (2017). The relations between Van Der Waals and covalent forces in layered crystals. Doctoral thesis, Nanyang Technological University, Singapore. http://hdl.handle.net/10356/69485 https://doi.org/10.32657/10356/69485 Downloaded on 10 Oct 2021 01:39:43 SGT THE RELATIONS BETWEEN VAN DER WAALS AND COVALENT FORCES IN LAYERED CRYSTALS CHATURVEDI APOORVA SCHOOL OF MATERIALS SCIENCE AND ENGINEERING 2016 THE RELATIONS BETWEEN VAN DER WAALS AND COVALENT FORCES IN LAYERED CRYSTALS CHATURVEDI APOORVA SCHOOL OF MATERIALS SCIENCE AND ENGINEERING A thesis submitted to the Nanyang Technological University in partial fulfilment of the requirement for the degree of Doctor of Philosophy 2016 Statement of Originality I hereby certify that the work embodied in this thesis is the result of original research and has not been submitted for a higher degree to any other University or Institution. 5th August 2016 . Date (CHATURVEDI APOORVA) Abstract Abstract With the advent of graphene that propels renewed interest in low-dimensional layered structures, it is only prudent for researchers’ world over to develop a deep insight into such systems with an eye for their unique “game-changing” properties. An absence of energy band gap in pristine graphene makes it unsuited for logic electronics applications. This led academia to turn their attention towards structurally similar semiconducting counterparts of graphene, layered transition metal dichalcogenides (LTMDs). Prominent in them, MoS2, WSe2 shows tuning of physical properties including band gap with reduced thickness and even an indirect to direct band gap transition when reduced to monolayer.
    [Show full text]
  • The Commensurate–Incommensurate Charge-Density-Wave Transition
    R. Samnakay, D. Wickramaratne, T. R. Pope, R. K. Lake, T. T. Salguero and A.A. Balandin (2014) The Commensurate–Incommensurate Charge-Density-Wave Transition and Phonon Zone Folding in 1T-TaSe2 Thin Films R. Samnakay1, 2, D. Wickramaratne 3, T. R. Pope 4, R. K. Lake 3, T. T. Salguero4 and A.A. Balandin1, 2, # 1Nano-Device Laboratory (NDL), Department of Electrical and Computer Engineering, University of California – Riverside, Riverside, California 92521 USA 2Phonon Optimized Engineered Materials (POEM) Center, Materials Science and Engineering Program, University of California – Riverside, Riverside, California 92521 USA 3Laboratory for Terascale and Terahertz Electronics (LATTE), Department of Electrical and Computer Engineering, University of California – Riverside, Riverside, California 92521 USA 4Department of Chemistry, University of Georgia, Athens, Georgia 30602 USA 1 | P a g e R. Samnakay, D. Wickramaratne, T. R. Pope, R. K. Lake, T. T. Salguero and A.A. Balandin (2014) Abstract Bulk 1T-TaSe2 exhibits unusually high charge density wave (CDW) transition temperatures of 600 K and 473 K below which the material exists in the incommensurate (I-CDW) and the commensurate (C-CDW) charge-density-wave phases, respectively. The 13 ´ 13C-CDW reconstruction of the lattice coincides with new Raman peaks resulting from zone-folding of phonon modes from middle regions of the original Brillouin zone back to . The C-CDW transition temperatures as a function of film thickness are determined from the evolution of these new Raman peaks and they are found to decrease from 473K to 413K as the film thicknesses decrease from 150 nm to 35 nm. A comparison of the Raman data with ab initio calculations of both the normal and C-CDW phases gives a consistent picture of the zone-folding of the phonon modes following lattice reconstruction.
    [Show full text]
  • Scruby-CB-1976-Phd-Thesis.Pdf
    1 SUPERSTRUCTURES AND CHARGE-DENSITY WAVES IN DISTORTED AND INTERCALATED LAYER MATERIALS A thesis presented for the degree of Doctor of Philosophy in the University of London by Christopher Brian Scruby Imperial College of May 1976 Science and Technology 2 acbtopctUvres Els Trio-ouv Heb.12 v 2. 3 ABSTRACT Transmission electron and X-ray diffraction studies, and high resolution phase-contrast electron microscopy, have shown that, except for NbS2,all the Group Va transition metal layer dichalcogenides are unstable with respect to periodic structural deformation in some temperature range. Inmommen- surate and commensurate distorted phases have been identified in 1T TaS2, 4Hb TaS2, IT VSe2 and 2H TaSe2. The deformations remain incommensurate in 2H NbSe2. The three distorted phases of IT TaS make this compound 2 unique; two are incommensurate. A detailed model of the deform- ation structure of 1T (room temperature phase) has been prop- 2 osed from diffractometer data, in which groups of metal atoms form planar clusters. The distortion modes on the Ta sublattice are predominantly LA, and on the S sublattice TA1 out of phase with the Ta by 2T/3. There are thus periodic variations in layer thickness and rhombohedral stacking of deformations. There is a 30% increase in deformation amplitude at the 1T -1.1T transition, and a further 15 % from 1T to 1T 1 2 2 3' 1T and 1T 3TaS also show some degree of metal clustering. 1 2 At the transition to the 15a x f a superlattice (1T3) there is a deformation stacking change to give a triclinic cell.
    [Show full text]
  • Pdf 993.48 K
    IJE TRANSACTIONS A: Basics Vol. 34, No. 4, (April 2021) 1052-1065 International Journal of Engineering Journal Homepage: www.ije.ir Exploration of Rhenium Volcanogenic Deposit and Technology Development Rylnikova M. V.a, Argimbaev K. R.*b, Ligotsky D. N.b a Research Institute of Comprehensive Exploitation of Mineral Resources of the Russian Academy of Sciences, Moscow, Russia Federation b Faculty of Mining, Saint Petersburg Mining University, St. Petersburg, Russia Federation P A P E R I N F O ABSTRACT Paper history: Rhenium is widely used in manufacturing industry and metallurgy. Today the consumption of rhenium Received 30 November 2020 is high, but there are very few deposits in the world where it is mined. Thus, the aim of the study is to Received in revised form 30 December 2020 identify areas of distribution of rhenium on Kudryavy volcano, located on the islands of the Kuril ridge Accepted 15 January 2021 (Russia). In this connection, during the field period, we took samples of a volcanic massif weighing 70 kg, and also studied the geothermal fields with a pyrometer. Laboratory research included the study of Keywords: composition of samples by the method of inductively coupled plasma mass spectrometry and Rhenium spectrometric analysis. The article defines the zones of distribution of rhenium mineralization, presents Volcanogenic Deposit the results of measurements of the temperature of geothermal fields and the elemental composition of Scoop Conveyor technological samples. The geology, development technology is described, the analysis of the Geothermal Fields destruction of rocks, determined by the acoustic method, the specific resistance of breakdown during electrothermal loosening is given.
    [Show full text]
  • Raman Studies of 2-Dimensional Van Der Waals Materials
    Raman Studies of 2-Dimensional van der Waals Materials By: Robert Christopher Schofield The University of Sheffield Faculty of Science Department of Physics and Astronomy A thesis submitted in partial fulfilment of the requirements for the degree of: Doctor of Philosophy Submission date: February 2018 Dedication For the love of my parents; Maggie & Peter . i ii Abstract Raman Studies of 2-Dimensional van der Waals Materials Robert Christopher Schofield Presented herein are results of optical studies with emphasis on the Raman response, providing significant contribution to the knowledge of the field. In MoxW(1−x)S2, confirmation of the behaviour of the excitonic properties is made. Raman measurements performed in this system allow investigation with unprecedented resolution, highlighting deviations in the high frequency A1g optical phonon mode from theoretical predictions, and previous experimental studies. In the low frequency, data confirms the trends in the shear and breathing interlayer modes in alloys between WS2 and MoS2 are well described by the modification in the square density. Resonant excitation for [Mo] < 0.4, highlights new evidence for the understanding of the hitherto unexplained ‘Peak X’ resonant feature. Diverse indium-selenium compounds isolated by novel means are studied. The ULF Raman modes of PDMS exfoliated InSe are documented for the first time, demonstrating the ε-phase with ABA stacking, with flake of thickness N manifesting (N −1) shear modes owing to resonant excitation of few layer samples. InSe flakes encapsulated in hexagonal boron nitride manifest different stacking orders to those of PDMS exfoliated InSe, and were found to have significant contamination, with crystalline degradation of the monolayer flake, and peaks corresponding N2 &O2 rotational modes present.
    [Show full text]
  • ( 12 ) United States Patent
    US009748371B2 (12 ) United States Patent ( 10 ) Patent No. : US 9 , 748 ,371 B2 Radosavljevic et al. ( 45 ) Date of Patent : Aug . 29 , 2017 (54 ) TRANSITION METAL DICHALCOGENIDE ( 56 ) References Cited SEMICONDUCTOR ASSEMBLIES ( 71 ) Applicant : Intel Corporation , Santa Clara , CA U . S . PATENT DOCUMENTS (US ) 2007 /0181938 A1 8 /2007 Bucher et al . ( 72 ) Inventors: Marko Radosavljevic , Portland , OR 2009/ 0146141 A1 6 /2009 Song et al. (US ) ; Brian S . Doyle , Portland , OR (Continued ) (US ) ; Ravi Pillarisetty , Portland , OR (US ) ; Niloy Mukherjee , Portland , OR FOREIGN PATENT DOCUMENTS (US ) ; Sansaptak Dasgupta , Hillsboro , OR (US ) ; Han Wui Then , Portland , KR 101348059 B1 1 / 2014 OR (US ) ; Robert S . Chau , Beaverton , WO 2012093360 A1 7 / 2012 OR (US ) ( 73 ) Assignee : INTEL CORPORATION , Santa Clara , OTHER PUBLICATIONS CA (US ) International Search Report and Written Opinion mailed Dec . 11 , ( * ) Notice : Subject to any disclaimer, the term of this 2014 , issued in corresponding International Application No . PCT/ patent is extended or adjusted under 35 US2014 /031496 , 10 pages . U . S . C . 154 (b ) by 0 days . (Continued ) (21 ) Appl. No. : 15 /120 , 496 ( 22 ) PCT Filed : Mar. 21 , 2014 Primary Examiner — Jaehwan Oh (86 ) PCT No .: PCT /US2014 /031496 (74 ) Attorney , Agent, or Firm — Schwabe, Williamson & $ 371 (c ) ( 1 ) , Wyatt , P . C . ( 2 ) Date : Aug . 19 , 2016 ( 87 ) PCT Pub . No . : WO2015 / 142358 (57 ) ABSTRACT PCT Pub . Date : Sep . 24 , 2015 Embodiments of semiconductor assemblies, and related (65 ) Prior Publication Data integrated circuit devices and techniques, are disclosed US 2017 /0012117 A1 Jan . 12 , 2017 herein . In some embodiments , a semiconductor assembly (51 ) Int. CI. may include a flexible substrate , a first barrier formed of a HOIL 29 / 778 ( 2006 .
    [Show full text]
  • Curriculum Vitae
    ALEXANDER A. BALANDIN Distinguished Professor, Department of Electrical and Computer Engineering University of California Presidential Chair Professor Director, Phonon Optimized Engineered Materials (POEM) Center Director, Center for Nanoscale Science and Engineering (CNSE) Nanofabrication Facility Founding Chair, Materials Science and Engineering (MS&E) Program Associate Director, DOE Spins and Heat in Nanoscale Electronic Systems (SHINES) EFRC University of California – Riverside, CA 92521 USA Balandin Group web-site: http://balandingroup.ucr.edu/ E-mail: [email protected] EDUCATION AND PROFESSIONAL PREPARATION • Postdoctoral Research, University of California - Los Angeles, USA, 1997 – 1999 • Ph.D. in Electrical Engineering, University of Notre Dame, Notre Dame, USA, 1996 • M.S. in Electrical Engineering, University of Notre Dame, Notre Dame, USA, 1995 • M.S. in Applied Physics, Moscow Institute of Physics and Technology, Russia, 1991 • B.S. in Mathematics, Moscow Institute of Physics and Technology, Russia, 1989 RESEARCH INTERESTS Advanced materials and nanostructures for applications in electronics, optoelectronics and energy conversion; quantum computing, spintronics, emerging devices and alternative computational paradigms; Raman and Brillouin spectroscopy; graphene and low-dimensional van der Waals materials; phonon engineering and thermal transport; low-frequency electronic noise in materials and devices; electronic noise spectroscopy EMPLOYMENT HISTORY • Director (2016 – present), Center for Nanoscale Science and Engineering
    [Show full text]
  • Polytypism, Polymorphism and Superconductivity in Tase2-Xtex
    Polytypism, polymorphism and superconductivity in TaSe2-xTex Huixia Luo1, Weiwei Xie1, Jing Tao2, Hiroyuki Inoue3, András Gyenis3, Jason W. 1 3 2 1 Krizan , Ali Yazdani , Yimei Zhu , and R. J. Cava 1Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA. 2Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, USA. 3Joseph Henry Laboratories and Department of Physics, Princeton University, Princeton, New Jersey 08544, USA. * [email protected];[email protected] 1 Polymorphism in materials often leads to significantly different physical properties - the rutile and anatase polymorphs of TiO2 are a prime example. Polytypism is a special type of polymorphism, occurring in layered materials when the geometry of a repeating structural layer is maintained but the layer stacking sequence of the overall crystal structure can be varied; SiC is an example of a material with many polytypes. Although polymorphs can have radically different physical properties, it is much rarer for polytypism to impact physical properties in a dramatic fashion. Here we study the effects of polytypism and polymorphism on the superconductivity of TaSe2, one of the archetypal members of the large family of layered dichalcogenides. We show that it is possible to access 2 stable polytypes and 2 stable polymorphs in the TaSe2- xTex solid solution, and find that the 3R polytype shows a superconducting transition temperature that is nearly 17 times higher than that of the much more commonly found 2H polytype. The reason for this dramatic change is not apparent, but we propose that it arises either from a remarkable dependence of Tc on subtle differences in the characteristics of the single layers present, or from a surprising effect of the layer stacking sequence on electronic properties that instead are expected to be dominated by the properties of a single layer in materials of this kind.
    [Show full text]