bluuebunny/crossref_metadata_2025 huggingface dataset:
Perching and takeoff of a robotic insect on overhangs using switchable electrostatic adhesion
Authors: Graule M. A. , Chirarattananon P. , Fuller S. B. , Jafferis N. T. , Ma K. Y. , Spenko M. , Kornbluh R. , Wood R. J.
Published: May 2016

Making small robots stick

Aerial views offer the chance to observe a wide range of terrain at once, but they come at the cost of needing to stay aloft. Graule
et al.
found that electrostatic forces could keep their insect-sized flying robot stuck to the underside of a range of surfaces (see the Perspective by Kovac). They mounted an electrostatically charged pad to the top of their robot, which could then reversibly stick to existing elevated perches—including a leaf—using less power than would be needed for sustained flight.

Science
, this issue p.
978
; see also p.
895
Changing of the guard
Authors: Howorka Stefan
Published: May 2016

DNA nanostructures mimic membrane proteins
Learning from nature how to land aerial robots
Authors: Kovac Mirko
Published: May 2016

Smaller robots can use mechanical intelligence to simplify the task of perching on a target
Preprints for the life sciences
Authors: Berg Jeremy M. , Bhalla Needhi , Bourne Philip E. , Chalfie Martin , Drubin David G. , Fraser James S. , Greider Carol W. , Hendricks Michael , Jones Chonnettia , Kiley Robert , King Susan , Kirschner Marc W. , Krumholz Harlan M. , Lehmann Ruth , Leptin Maria , Pulverer Bernd , Rosenzweig Brooke , Spiro John E. , Stebbins Michael , Strasser Carly , Swaminathan Sowmya , Turner Paul , Vale Ronald D. , VijayRaghavan K. , Wolberger Cynthia
Published: May 2016

The time is right for biologists to post their research findings onto preprint servers
Complete Genome Sequence of a Novel Avian Paramyxovirus (APMV-13) Isolated from a Wild Bird in Kazakhstan
Authors: Karamendin K. , Kydyrmanov A. , Seidalina A. , Asanova S. , Sayatov M. , Kasymbekov E. , Khan E. , Daulbayeva K. , Harrison S. M. , Carr I. M. , Goodman S. J. , Zhumatov K.
Published: May 2016

A novel avian paramyxovirus was identified during annual viral surveillance of wild bird populations in Kazakhstan in 2013. The virus was isolated from a white fronted goose (
Anser albifrons
) in northern Kazakhstan. Here, we report the complete genome sequence of the isolate, which we suggest should constitute a novel serotype.
Draft Genome Sequence of a Multidrug-Resistant Klebsiella pneumoniae Strain Isolated from King Abdullah Medical City, Makkah, Saudi Arabia
Authors: Algowaihi Rayd , Ashgar Sami , Sirag Bashir , Shalam Sheerin , Nassir Anmar , Ahmed Abdalla
Published: May 2016

Multidrug-resistant (MDR) Gram-negative infections represent a growing problem and a serious global threat. Carbapenem-resistant
Klebsiella pneumoniae
is perhaps cause the most difficult infection to treat and is associated with increased morbidity and mortality. Here, we report the draft genome sequence of an MDR
K. pneumoniae
strain isolated from Makkah, Saudi Arabia.
Draft Genome Sequence of the Oleaginous Yeast Cryptococcus albidus var.
albidus
Authors: Vajpeyi Shashwat , Chandran Kartik
Published: May 2016

We report the complete draft genome sequence of
Cryptococcus albidus
var.
albidus
, an oleaginous yeast, which can utilize various organic carbon sources for lipid synthesis. Availability of this genome will help elucidate factors driving lipid accumulation in
C. albidus
and contribute toward bioprocess development and optimization for engineered lipid production.
Complete Sequence of the Smallest Polyomavirus Genome, Giant Guitarfish (
Rhynchobatus djiddensis
) Polyomavirus 1
Authors: Dill Jennifer A. , Ng Terry F. F. , Camus Alvin C.
Published: May 2016

Polyomaviruses are known to infect mammals and birds. Deep sequencing and metagenomic analysis identified the first polyomavirus from a cartilaginous fish, the giant guitarfish (
Rhynchobatus djiddensis
). Giant guitarfish polyomavirus 1 (GfPyV1) has typical polyomavirus genome organization, but is the smallest polyomavirus genome (3.96 kb) described to date.
Genetic Characterization of Providence Virus Isolated from Bat Guano in Hungary
Authors: Kemenesi Gábor , Földes Fanni , Zana Brigitta , Kurucz Kornélia , Estók Péter , Boldogh Sándor , Görföl Tamás , Bányai Krisztián , Oldal Miklós , Jakab Ferenc
Published: May 2016

We report the complete genome sequence and genetic characterization of a novel strain of Providence virus, detected in
Barbastella barbastellus
bat guano, collected in Hungary in 2014. Our data may facilitate the understanding of the evolutionary processes of this unique viral family of
Carmotetraviridae.
High frequency ofJAK2exon 12 mutations in Korean patients with polycythaemia vera: novel mutations and clinical significance
Authors: Park Chang-Hun , Lee Ki-O , Jang Jun-Ho , Jung Chul Won , Kim Jong-Won , Kim Sun-Hee , Kim Hee-Jin
Published: May 2016

Gain-of-function mutations inJAK2are the molecular hallmarks of polycythaemia vera (PV), one of the myeloproliferative neoplasms. Most (∼95%) patients harbour V617F mutation in exon 15, while the rest have small insertion/deletion mutations in exon 12. We investigatedJAK2mutations in 42 Korean patients with PV. V617F was detected by sequencing and allele-specific PCR. When V617F was negative, sequencing and fragment length analyses were performed to detect exon 12 mutations. As a result, all patients hadJAK2mutations: 37 (88%) harboured V617F, and 5 (12%) had exon 12 mutations. Two patients had novel exon 12 mutations (H538_R541delinsLII and F537_K539delinsVL). Genotype–phenotype correlations demonstrated lower white blood cell and platelet counts in exon 12 mutations than V617F. The frequency ofJAK2exon 12 mutations was higher than expected in Korean patients with PV. Molecular genetic testing forJAK2exon 12 mutations is mandatory for diagnosis and genotype–phenotype correlations in patients with erythrocytosis and suspected PV.
Fermi energy for hard-sphere gas in porous media and potential fields
Authors: Pang Hai , Wu Sen
Published: May 2016

In this paper, we introduce a method for analytically calculating the Fermi energy. As an example, we study the hard-sphere (HS) gas, the gas in porous media and the gas in an external potential field or curved background. These examples are valuable for studying the spectral structure of a real gas.
Pyrolytic carbon microelectrodes for impedance based cell sensing
Authors: Mohamed Hassan Yasmin , Caviglia Claudia , Hemanth Suhith , Mackenzie David M. A. , Petersen Dirch H. , Keller Stephan Sylvest
Published: May 2016

Electrically conductive glass-like carbon structures can be obtained from a polymer template through a pyrolysis process. These structures can be used as electrodes for bio sensing applications such as electrochemical evaluation of cell adhesion and proliferation. This study focuses on the optimization of two dimensional (2D) pyrolytic carbon microelectrodes with the carbon MEMS (C-MEMS) process using the negative epoxy photoresist SU-8. Different electrochemical microchips with carbon working (WE) and counter electrode (CE) were fabricated. More specifically, pyrolysis process was optimized to decrease the resistivity of the resulting carbon material and improve the performance in cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Finally, EIS was used to monitor adhesion and proliferation of HeLa cells.
A New Approach for Selective Surface Functionalization of Carbon Electrodes in Biosensing by Plasma Direct-Writing
Authors: Thiha Aung , Ibrahim Fatimah , Abd Hamid Sharifah Bee , Madou Marc J
Published: May 2016

Carbon electrodes fabricated by Carbon Microelectromechanical systems (C-MEMS) process is known to be chemically inert. Hence, surface functionalization is required for their use as biosensors and electrochemical electrodes. Surface functionalization of carbon electrodes is conventionally performed by oxygen plasma treatment or acid treatments. These methods generally affect the whole surface of electrodes and cannot limit functionalization to only at specific locations on the electrodes. This paper introduces a novel plasma direct-writing technique for selective functionalization of carbon electrodes with carboxylic groups at room temperature and atmospheric pressure. We demonstrated the plasma direct-writing by patterning oxygen functional groups on carbon electrodes derived from pyrolysis of photolithographically patterned photoresist. The resulting surface chemistry is investigated by scanning electron microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDS). Functionalization of hydroxyl and carboxyl groups is a first step towards immobilization of DNA or immunoglobulin for carbon based biosensors. Our plasma direct-writing technique not only enables controlled writing of functional groups but also enables control over the degree of functionalization in a simple one step procedure.
SU-8/MWCNT derived Electrospun Composite Carbon Nanofabric as a High Performance Anode Material for Lithium Ion Battery
Authors: Kakunuri Manohar , Kaushik Shubham , Saini Ayush , Sharma Chandra Shekhar
Published: May 2016

SU-8, an epoxy based negative photoresist was electrospun with a fixed amount of multiwall carbon nanotubes (MWCNT) added into it to form the long, uniform, and bead-free fibers. These composite electrospun fibers were then subjected to pyrolysis in inert atmosphere at 1173 K to yield carbon nanofibers with enhanced crystallinity as revealed by structural characterization. Although the morphology of the nanofibers before and after pyrolysis was found to be largely unaffected however there was a shrinkage of nearly 32% in the average fiber diameter upon pyrolysis. As-synthesized electrospun composite carbon nanofibers were then tested directly without adding a binder for their electrochemical performance as anode for lithium ion battery. A significantly higher reversible capacity of 1320 mAh/g was observed at 0.1 C-rate with excellent initial efficiency of 54%. Similarly at high C-rates also, electrochemical performance was found to be excellent primarily due to enhanced crystallinity with the addition of MWCNT and entangled morphology of electrospun carbon nanofibers.
Development of Pyrolyzed Nanoporous Carbon Electrodes with Sponge-like Networks of Mesopores for Use as Supercapacitors
Authors: Lim Yeongjin , Joo Sang Hoon , Shin Heungjoo
Published: May 2016

We developed patternable nanoporous carbon microstructures fabricated using simple O2 plasma etching and carbon-MEMS for the application of supercapacitors. Carbon-MEMS is a versatile microfabrication technology enabling batch fabrication of micro-/nano-sized carbon structure of complex architecture at a wafer level using conventional UV-lithography and pyrolysis. By incorporating a simple O2 plasma etching process prior to the pyrolysis, sponge-like nanoporous surface is formed on the top surface of pre-patterned SU-8 photoresist structures due to self-masking effect. These O2-plasma-treated photoresist structures are converted into nanoporous carbon electrodes via pyrolysis while maintaining surface morphology of sponge-like nanoporous networks. The surface area and electrochemical capacitance of the nanoporous carbon are enhanced significantly compared to a bare carbon surface. The pore size and surface morphology of the nanoporous carbon are controllable depending on O2 plasma etching time.
Pyrolytic 3D Carbon Microelectrodes for Electrochemistry
Authors: Hemanth Suhith , Caviglia Claudia , Amato Letizia , Anhøj Thomas Aarøe , Heiskanen Arto , Emnéus Jenny , Keller Stephan Sylvest
Published: May 2016

This work presents the fabrication and characterization of suspended three-dimensional (3D) pyrolytic carbon microelectrodes for electrochemical applications. For this purpose, an optimized process with multiple steps of UV photolithography with the negative tone photoresist SU-8 followed by pyrolysis at 900ºC for 1h was developed. With this process, microelectrode chips with a three electrode configuration were fabricated and characterized with cyclic voltammetry (CV) using a 10mM potassium ferri-ferrocyanide redox probe in a custom made batch system with magnetic clamping. The 3D pyrolytic carbon microelectrodes displayed twice the higher peak current compared to 2D.
Characterization of SiOx/HfOx Bilayer Resistive-Switching Memory Devices
Authors: Chen Ying-Chen , Chang Yao-Feng , Wu Xiaohan , Guo Meiqi , Fowler Burt , Zhou Fei , Pan Chih-Hung , Chang Ting-Chang , Lee Jack C.
Published: May 2016

Oxide based resistive switching memory (ReRAM or RRAM) are the promising candidates for future non-volatile memory due to its fast programing, low power operation, and scalability. Among them, SiOx single layer resistive switching (RS) devices have been widely studied and characterized. The SiOx single layer resistive memory has excellent compatibility to CMOS fabrication process. However, it can only be programmed under the vacuum or non-oxidized ambient. Also, previous results reported on SiOx-based memristors indicate that the electroforming and programming voltages are relatively high, especially for low-power applications. In this work, by using SiOx/HfOx stacked structure, we have developed a low-voltage operation (< 2V) for SiOx-based ReRAM. The results show that with HfOx
(3nm) on bottom, the metal-insulator-semiconductor (MIS) structures exhibit resistive switching at low voltage (< 2V) and operation in air atmosphere. The added hafnium layer is believed to provide a source to proton exchange reaction with conduction bandgap offset reduction for low-voltage (< 2V) RS. Furthermore, we have studied single HfOx-based MIS devices which exhibit bipolar-type resistive switching behaviors with small memory window. Clearly, SiOx/HfOx stacking optimization not only maintains the RS behaviors even in air environment without any programming window degradation, but also reduces the switching voltage below 2V.
(Invited) III-V Selective Area Growth and Epitaxial Functional Oxides on Si: From Electronic to Photonic Devices
Authors: Merckling Clement , Liu Ziyang , Hsu Mark , Hasan Samiul , Jiang Sijia , El Kazzi Salim , Boccardi Guillaume , Waldron Niamh , Wang Zhechao , Tian Bin , Pantouvaki Marianna , Van Campenhout Joris , Collaert Nadine , Heyns Marc , Van Thourhout Dries , Vandervorst Wilfried , Thean Aaron
Published: May 2016

This review paper presents the challenges for the monolithic integration on silicon substrate by heteroepitaxy of III-V semiconductors selective area growth as well as epitaxial functional oxides. The heteroepitaxy of these materials on a common Si platform would allow the integration of new functionalities and advanced devices in both electronic and photonic areas.
(Invited) Gate-All-Around Nanowire FETs vs. Triple-Gate FinFETs: On Gate Integrity and Device Characteristics
Authors: Veloso Anabela , Cho Moon Ju , Simoen Eddy , Hellings Geert , Matagne Philippe , Collaert Nadine , Thean Aaron
Published: May 2016

This work reports a comprehensive evaluation of lateral gate-all-around (GAA) nanowire (NW) FETs vs. triple-gate finFETs, with both types of devices built with various doping schemes, and with GAA-NWFETs outperforming others per footprint. Optimized junctionless (JL) GAA-NWFETs exhibit excellent electrostatics and smaller IOFF values. They also yield ring oscillators with substantially lower power dissipation, while showing considerably longer BTI lifetimes. Improved reliability and increased robustness against process variations in the GAA formation module are also obtained for extensionless vs. reference inversion-mode (IM) FETs built with conventional junctions, at comparable device and circuit performance. JL GAA-NWFET devices also show improved on and off state hot carrier (HC) reliability and reduced LF noise, with some of them also exhibiting smaller subthreshold slope values after HC stress. In addition, further improvements in the noise, reliability and mobility performance of GAA-NWFETs can be obtained by introduction of a TiAl-based EWF-metal in the gate stack.
A Comprehensive Analytical Study of Subthreshold Swing for Cylindrical Gate-All-Around Junctionless Field Effect Transistor
Authors: Ahmed Imtiaz , Khosru Quazi D. M.
Published: May 2016

An analytical subthreshold swing (SS) model for Cylindrical Gate-All-Around Junctionless Field Effect Transistor (CGAA JLFET) has been proposed in this work. Basically, 2D Poisson equation has been solved along the channel while assuming a parabolic potential distribution across the radial direction of the silicon channel, which in turn leads to some explicit relationships of the body center potential, subthreshold current and swing for CGAA JLFET. Performance analysis of subthreshold behaviors i.e. subthreshold current and swing for CGAA JLFET has been made by using different design parameters such as, gate electrode material, gate oxide thickness, silicon channel diameter and doping concentration of the channel.
(Invited) Non-Destructive Characterization of Dielectric - Semiconductor Interfaces by Second Harmonic Generation
Authors: Ionica Irina , Damianos Dimitrios , Kaminski Anne , Vitrant Guy , Blanc-Pélissier Danièle , Changala John , Kryger Marc , Barbos Corina , Cristoloveanu Sorin
Published: May 2016

Here we present the characterization of dielectric - semiconductor interfaces using optical second harmonic generation (SHG). The technique is contactless, which makes it useful for non-destructive monitoring of ultra-thin dielectrics. The generated second harmonic is sensitive to material parameters and charges near interfaces. The signal exhibits time dependence due to charging of traps with carriers generated by the incident laser during the measurement. Quantitative models are applied to the time dependent SHG signals in the Al2O3 stacks, which provide trapping kinetics information, and thus Al2O3 film quality. Al2O3 films are commonly used for passivating Si in photovoltaic stacks. To further demonstrate that time dependent behavior is due to changes in the electric field across the semiconductor/dielectric interface, additional systems are presented for comparison: SiNx on silicon, passivated and non-passivated silicon-on-insulator substrates. Results confirm the value of SHG as a quality control method for multiple thin film dielectrics.
(Invited) A Complete Suite of Experimental Techniques for Electrical Characterization of Conventional and Incoming High-k Dielectric-Based Devices
Authors: Dueñas Salvador , Castán Helena , García Héctor , Arroval Tonis , Tamm Aile , Kukli Kaupo , Aarik Jaan
Published: May 2016

High permittivity (high-k) dielectric films are of considerable interest as gate oxide materials in advanced complementary metal-oxide-semiconductor (CMOS), in metal-insulator-metal capacitors (MIM), and in dynamic and resistive random access memory devices as well. These materials need to be characterized and qualified prior to their inclusion on massive fabrication processes. In this work we review the standard and new electrical characterization techniques available in our laboratory for the electrical characterization of thin high-k layer-based metal-insulator-semiconductor (MIS) and metal-insulator-metal structures. All of them constitute a complete suite of experimental techniques to carry out an in-depth study of conventional and incoming high-k based devices.
Performance Analysis of InAs/AlSb MOS-HEMT by Self-Consistent Capacitance-Voltage Characterization and Direct Tunneling Gate Leakage Current
Authors: Ahmed Imtiaz , Chowdhury Sayema , Alam Md. Hasibul , Niaz Iftikhar Ahmad , Khosru Quazi D. M.
Published: May 2016

In this paper, Capacitance-Voltage (CV) characteristics and direct tunneling gate leakage performance of InAs/AlSb Metal Oxide Semiconductor High Electron Mobility Transistor (MOS-HEMT) are investigated. 1-D coupled Schrӧdinger-Poisson equations are solved for electrostatic characterization of InAs/AlSb MOS-HEMT considering wave function penetration and strain effects. Using modified Wentzel–Kramers–Brillouin (WKB) method for transmission probability, direct tunneling gate leakage current is also calculated for the MOS-HEMT structure. Dependence of CV characteristics and direct tunneling gate leakage current on some important process and physical parameters such as oxide thickness, channel thickness, capping layer composition, gate dielectric material, doping concentration of delta layer and temperature are studied in this work. Our simulation results agree the pattern of variation with the experimental results reported by H. K. Lin et al.
(Invited) Trench-Gated MOSFET Instability Caused by High Temperature Reverse-Bias Stress
Authors: Hao Jifa
Published: May 2016

We discuss the instability of trench-gated MOSFET under high temperature reverse-bias stress (HTRB) and highly accelerated temperature & humidity stress test (HAST). We have observed that gate oxide interface trap density has been increased at both HTRB stress and HAST stress. However humid HAST stress is observed to further introduce mobile positive charge in the gate oxide of the trench-gated MOSFET. This positive charge is argued to be proton (H+). The HTRB stress or HAST stress is a negative bias temperature instability (NBTI) in a parasitic p-channel MOSFET structure occurring in the trench-gate n-channel MOSFET. The NBTI is enhanced by the presence of moisture in the oxide.
(Invited) Process and Integration of Dielectrics Required for 10nm and Beyond Scaling
Authors: Clark Robert D. , Tapily Kandabara , Consiglio Steven , Hakamata Takahiro , O'Meara David , Newman Daniel , Collings Michael , Szymanski Dennis , Wajda Cory S. , Leusink Gert J.
Published: May 2016

Dielectric materials with tailored properties are required to meet future device and integration needs. Deposition processes that are self-limited (e.g. Atomic Layer Deposition (ALD)), or self-directed (e.g. selective deposition) will enable those materials to be used in scaled 3D devices incorporating new channel materials. Highly tailored ALD processes are being investigated to fabricate functional material layers. Interspersed treatments and doping to make ternary materials may be used to modify the physical and electrical properties of ALD films further in order to optimize the resulting physical or electrical properties. Examples of these and similar processes are described and discussed with the goal of discerning a path beyond 10nm devices.
Dry and Wet Processed Interface Layer in Ge/High-K Devices Studied by Deep Level Transient Spectroscopy
Authors: Ding YI Ming , Misra Durga
Published: May 2016

Dry and wet processed interface layer quality of Ge/high-k MOS structures were studied by deep level transient spectroscopy (DLTS). The interface treatments were: (i) simple chemical oxidation (Chemox); (ii) chemical oxide removal (COR) followed by 1 nm oxide by slot-plane-antenna (SPA) plasma (COR&SPAOx); and (iii) COR followed by vapor O3 treatment (COR&O3). By conducting deep level transient spectroscopy (DLTS) on these three samples, it is found that the dry processed interface (COR&SPAOx and COR&O3) showing a majority slow trap which was not observed in wet processed interface treatment (Chemox). This results clearly suggest that formation of a different type of interfacial GeOx is responsible for the the additional defect type in dry processed devices.
Electrochemical Characterization of Synthetic Hybrid DNA Molecular Wires
Authors: Golkar Narenji Alaleh , Goshi Noah , Coste Michael , Burns Dillon , Lee Raymond , Ngo Katrina , Purse Byron , Kassegne Sam
Published: May 2016

As a viable solution to long-term stability problems associate with DNA molecular wires along with the additional benefits of tuning their conductivity, hybrid DNA molecular wires made of natural base-pairs and synthetic base-pairs, which have lower ionization potentials and a more π orbital overlapping, offer an attractive option. A strong synthetic nucleotide candidate is tricyclic cytosine analogue (such as (8-MeO)tC), which we show has (i) a lower ionization potential (~ 0.65V) compared to natural nucleotides, G (1.29V), C (1.6V), A (1.42V), T (1.7V) and (ii) more π-orbital stacking due to its tricyclic structure. Moreover, to illuminate the importance of the π orbital stack to the conductivity of DNA molecular wires, in this paper, we compared the conductivity of wild-type (WT) DNA and DNA sequences containing mismatched base-pairs that perturb the π orbital stack. Lower conductivity was obtained when modifying the surface of the gold electrodes with both WT and mismatched DNA. Further, chips functionalized with DNA sequences with mismatched base-pairs were observed to have lower conductivity than those functionalized with WT DNA sequences.
(Invited) Fabrication of Implantable Glucose Fuel Cells on Silicon Wafers
Authors: Cabrera Rafmag , Weaver Isaac , Banerjee Areen , Sarpeshkar Rahul , Thorsen Todd
Published: May 2016

Well-known silicon micro fabrication techniques are used to create biocompatible abiotic glucose fuel cells, suitable for powering ultra-low-power bioelectronics on a silicon wafer. Measured continuous outputs of 2.3 µW/cm2 at 0.243V were achieved and maintained for a period of at least 48 hr with an open circuit voltage of 0.55V. Fabrication processes are discussed to address the difficulty in depositing and patterning Nafion separation membranes robustly and in the creation of a uniform carbon nanotube mesh catalyst.
(Invited) More Than Moore Applications with Thin-Film-Transistors Array Substrates from Liquid Cristal Display: New Devices for Biological Cells Analyses
Authors: Tixier-Mita Agnes , Ihida Satoshi , Cathcart Grant Alexander , Shaik Faruk Azam , Toshiyoshi Hiroshi
Published: May 2016

Thin film transistor technology, mainly applied to liquid cristal displays, is used in this article for a new application, in a “More than Moore” objective, proposing new and unique solutions in the biomedical field. The devices fabricated with that technology are electrically controllable transparent substrates, perfectly suitable to build advanced systems for biological cells purposes. In addition, the transistor array, initially used as simple switches to control the pixels ON and OFF state of TFT-LCD, becomes an active part in the device, allowing not only DC or AC signal application, but also sensing, either through the microelectrodes, or directly being themselves a possible array of ISFETs. This article presents the results obtained until now by our group, which demonstrate the potential of such technology in the frame of biological cells research.
(Invited) Comprehensive Assessment of Oxide Memristors As Post-CMOS Memory and Logic Devices
Authors: Gao Xujiao , Mamaluy Denis , Cyr Eric C. , Marinella Matthew J.
Published: May 2016

As CMOS technology approaches the end of its scaling, oxide-based memristors have become one of the leading candidates for post-CMOS memory and logic devices. To facilitate the understanding of physical switching mechanisms and accelerate experimental development of memristors, we have developed a three-dimensional fully-coupled electrical and thermal transport model, which captures all the important processes that drive memristive switching and is applicable for simulating a wide range of memristors. The model is applied to simulate the RESET and SET switching in a 3D filamentary TaOx memristor. Extensive simulations show that the switching dynamics of the bipolar device is determined by thermally-activated field-dominant processes: with Joule heating, the raised temperature enables the movement of oxygen vacancies, and the field drift dominates the overall motion of vacancies. Simulated current-voltage hysteresis and device resistance profiles as a function of time and voltage during RESET and SET switching show good agreement with experimental measurement.
Metal Oxide Thin Film Characterization for New Generation Chemical Mechanical Planarization Development
Authors: Basim G. Bahar , Karagoz Ayse
Published: May 2016

This study targets to create a basis for the process development in the new generation semiconductor industry dealing with atomic scale devices. We focus on the CMP process development as it is used for the current and future semiconductor materials in microelectronics industry for metallic, semiconductor and dielectric materials. Particularly, formation and atomic level removal mechanisms of the CMP induced metal oxide thin films for metallic layers and chemically modified hydrated layer interaction for the semiconductor films are presented as a focus for the new generation device manufacturing.
Influence of Doping and Tunneling Interface Stoichiometry on n+In0.5Ga0.5As/p+GaAs0.5Sb0.5 Esaki Diode Behavior
Authors: El Kazzi Salim , Alireza A , Bordallo Caio Cesar Mendes , Smets Quentin , Desplanque Ludovic , Wallart Xavier , Richard Olivier , Douhard Bastien , Verhulst Anne , Collaert Nadine , Merckling Clement , Heyns Marc , Thean Aaron
Published: May 2016

In this work, we study the influence of molecular beam epitaxy (MBE) growth parameters on the behavior of a staggered band gap n+In0.5Ga0.5As/p+GaAs0.5Sb0.5 Esaki diodes. We first first show that a careful doping is required to avoid any crystal defects. Then the influence of the doping concentration on the Band to Band Tunneling (BTBT) is discussed. At the end, we show that a careful monitoring of the MBE growth allows thin and abrupt n+In0.5Ga0.5As/p+GaAs0.5Sb0.5 tunneling interfaces where BTBT behavior in this case is independent of the III-V interface stoichiometry
(Keynote) Challenges of 10 nm and 7 nm CMOS for Server and Mobile Applications
Authors: Divakaruni Rama , Narayanan Vijay
Published: May 2016

FINFET technology is now available on cutting edge mobile devices starting at the 16/14nm nodes. As the industry ramps toward 7nm, there will be intense pressure on density to counter the added cost driven by the adoption of more complex multiple patterning techniques for the FIN, Gate, various Middle Of Line (MOL)architectures, and Back End Of Line (BEOL) wiring levels. The need to reduce doping in the FINFETs will drive Multi-Work function solutions for same gate polarity. Likewise, the need for transistor performance will lead to new channel materials. Novel materials will be needed to reduce parasitic capacitance and resistance in the MOL and BEOL levels. Some incarnations of the 10nm node will be called "7nm" just as some variants of 20nm node were called 16/14, but the true "7nm" node circuit densities will require the next generation of lithography -- Extreme Ultra Violet (EUV) at 13.5nm wavelength. The key to adoption in the mobile space is the cost of the chip which is challenged by the need for novel cost intensive patterning techniques. The key to adoption in the server space will be ability to get more performance at constant chip power given the increased wiring parasitics. In all cases, novel materials will be needed to get to mature 7nm nodes.
(Invited) Effect of Low Carbon Concentration on Bulk Lifetime of Silicon Crystal
Authors: Higasa Mitsuo , Nagai Yuta , Nakagawa Satoko , Kashima Kazuhiko
Published: May 2016

Reducing the electric loss of power semiconductor devices such as insulated-gate bipolar transistors (IGBTs) is necessary for saving energy and reducing fuel consumption. An essential factor for achieving low-loss IGBTs is increasing the bulk lifetime of the silicon crystals. To achieve a longer bulk lifetime, we reduced the carbon concentration in magnetic-field-applied Czochralski (MCZ) silicon. We investigated the bulk lifetime of MCZ silicon with ultralow-carbon-concentration and floating-zone (FZ) silicon to clarify the impact of carbon impurities on the bulk lifetime. The bulk lifetime was measured using a direct-current photoconductive decay method designated by ASTM F28-75. The bulk lifetime of MCZ silicon drastically increased with decreasing carbon concentration. MCZ silicon crystals with a carbon concentration less than 1.0 × 1015 atoms/cm3 exhibited a longer bulk lifetime than FZ silicon crystals. We demonstrated that carbon-concentration reduction is crucial for increasing the bulk lifetime of MCZ silicon crystals.
(Invited) TmSiO as a CMOS-Compatible High-k Dielectric
Authors: Dentoni Litta Eugenio , Hellström Per-Erik , Östling Mikael
Published: May 2016

Novel materials are being aggressively researched for integration in high-k/metal gate CMOS technology, as innovations in the gate stacks are necessary to sustain scaling toward the end of the roadmap. In this paper, we discuss thulium silicate as a candidate dielectric for integration as interfacial layer, focusing on compatibility with the requirements in terms of both process integration and effects on electrical device characteristics. In particular, we demonstrate that thulium silicate provides advantages over conventional chemical oxide interfacial layers in terms of scalability and channel mobility.
(Invited) Low-Temperature Microwave-Based Plasma Oxidation of Ge and Oxidation of Silicon Followed by Plasma Nitridation
Authors: Lerch Wilfried , Schick T. , Sacher N. , Kegel W. , Niess J. , Czernohorsky M. , Riedel Stefan
Published: May 2016

In the semiconductor industry Germanium is expected as the promising channel material for future high-mobility CMOS transistors because of its highest hole mobility among common elemental and compound semiconductors, and an electron mobility that is two times larger than that of Si. This article shows that oxides can be grown and/or in a subsequent process step nitridized for planar Ge and Si devices at very low temperatures (T < 460 °C). The stable oxide growth on Germanium through plasma processing is studied as a function of relevant processing parameters like time, gaseous ambient etc. For Silicon the bonding structure of pure and nitridized low-temperature grown SiO2 is analyzed, followed by an electrical characterization of 0.8 to 1.2 nm interfacial layers on Si.
Height Uniformity of Micro-Bumps Electroplated on Thin Cu Seed Layers
Authors: Yang Liu , Slabbekoorn John , Honore Mia , Stiers Karen , Struyf Herbert , Vereecken Philippe M , Radisic Aleksandar
Published: May 2016

In this study a quick and cost-effective approach is developed to evaluate the micro-bump height uniformity on wafer level. Our numerical simulation of bump-height distribution uses experimentally measured i-η curve, and requires no explicit knowledge of the plating bath components. Theoretical predictions are well matched with results obtained for Cu micro-bumps plated on 300 mm wafers with Cu seeds of varying thickness. The method can be easily adapted to address the challenges of fabrication of multi-layered features and different cell and electrode geometries.
Vapor Phase Self-Assembled Monolayers for CMOS BEOL Barrier Layers
Authors: Naik Tejas RAJENDRA , Ravikanth M , Rao Valipe RAMGOPAL
Published: May 2016

As the Back - End - of - Line (BEOL) Interconnects are scaling down to nanometer regime with multiple levels of metallization, need for ultra-thin diffusion barrier layers arise. Self assembled monolayer (SAM) is an ideal solution to satisfy the requirement of an ultra-thin barrier layer to avoid Copper diffusion. However, wet chemical processes are preferably avoided in Complimentary - Metal - Oxide - Semiconductor (CMOS) fabrication process. Accordingly, a novel technique to form SAM of Zinc (||) tetraphenyl hydroxy porphyrin (ZnTPPOH) in vapor phase on Inter - Layer Dielectric (ILD) materials is developed in present work to suit the industry process flow and be integreable in CMOS fabrication.
(Invited) Graphene Plane Electrode for Low Power 3D Resistive Random Access Memory
Authors: Lee Seunghyun , Sohn Joon , Jiang Zizhen , Chen Hong-Yu , Wong H. -S. Philip
Published: May 2016

In this work, we introduce one of the world’s thinnest non-volatile memory stacked in a 3-dimensional vertical structure. We exploit the edge of an atomically thin graphene layer and form a metal oxide resistive memory using HfOx as the switching oxide. We found that such thin memory has potential for highly integrated storage system with memory density higher than the same memory structure made using thin metal layer. We also confirm that it is not possible to build such thin memory with conventional metal because the sheet resistance of metal dramatically increases as it is thinned down to less than 5 nm.
Simulation of the Germanium-Tin Tunneling Field-Effect Transistors with a Ge Cap Layer: Improved Subthreshold Swing and Ion/Ioff Ratio
Authors: Liu Lei , Liang Renrong , Wang Jing , Xu Jun
Published: May 2016

Germanium-tin tunneling field-effect transistors (GeSn TFETs) with a Ge cap layer are comprehensively investigated by numerical device simulations. Inserting an ultrathin Ge cap layer between the high-k dielectric and the GeSn alloy aids the improvement of device performance owing to the better interface characteristics and the suppressed leakage current. The improved subthreshold characteristic is beneficial for enhancing the device performance at low supply voltages. The ultrathin Ge cap layer may be needed for the future high-performance GeSn TFETs applications.
Comprehensive Characterization of Dual Implanted Silicon after Electrical Activation Annealing
Authors: Yoo Woo Sik , Jeon Bong Seok , Kim Sang Deok , Ishigaki Toshikazu , Kang Kitaek
Published: May 2016

Phosphorous (P+ 1.0 MeV, 4.0 x 1013 cm-2) and boron (B+ 10 keV, 3.0 x 1014cm-2) implanted p--Si(100) wafers were prepared to study electrical activation and dopant diffusion properties during thermal annealing. Dual implanted Si wafers were annealed for a wide range of annealing conditions (350-800oC, 60-150s) in a commercially available hot wall-based, rapid thermal annealing (RTA) system. Systematic change of sheet resistance was measured in the dual implanted wafers annealed under different RTA conditions. P and B depth profiles measured by secondary ion mass spectroscopy (SIMS) did not show significant change in all RTA conditions. Room temperature photoluminescence (RTPL) spectra and Raman spectra were measured from all wafers under various excitation wavelengths (650 and 785 nm for RTPL and 363.8, 441.6, 457.9, 488.0 and 514.5 nm for Raman). RTPL spectra showed large variations in intensity and wavelength distribution corresponding to the resulting sheet resistance and RTA conditions. Raman spectra showed gradual increase of intensity and change of Raman peak positions and FWHM at the RTA temperatures for implant damage recovery and electrical activation of dual implanted Si wafers.
Hot-Wire Chemical Vapour Deposition for Silicon Nitride Waveguides
Authors: Domínguez Bucio Thalía , Tarazona Antulio , Khokhar Ali Z. , Mashanovich Goran Z. , Gardes Frederic Y.
Published: May 2016

In this work, we demonstrate the use of HWCVD as an alternative technique to grow SiN layers for photonic waveguides at temperatures <400ºC. In particular, the effect of the ammonia flow and the filament temperature on the material structure, optical properties and propagation losses of the deposited films was investigated. SiN layers with good thickness uniformity, roughness as low as 0.61nm and H concentration as low as 10.4x1021 atoms/cm3 were obtained. Waveguides fabricated on the studied materials exhibited losses as low as 7.1 and 12.3 dB/cm at 1310 and 1550nm respectively.
Effect of Post Plasma Oxidation on Ge Gate Stacks Interface Formation
Authors: Mukhopadhyay Sromana , Mitra Shilpa , Ding YI Ming , Ganapathi K.L. , Misra Durga , Bhat Navakanta , Tapily Kandabara , Clark Robert D. , Consiglio Steven , Wajda Cory S. , Leusink Gert J.
Published: May 2016

This work investigates the application of slot plane antenna plasma oxidation (SPAO) during dielectric depositionto processTiN/AlO/ZrO2/Ge MOS capacitors. The impact of SPAO exposure on effective oxide thickness (EOT), leakage current, interface state density (D
it), C-V hysteresis, oxide breakdown characteristics have been studied. Considerable degradation of electrical properties has been observed with SPAO being performed before AlO/ZrO2 gate stack deposition. When SPAO is performed in between AlO/ZrO2deposition, moderate increase in EOT and significant decrease in D
it was observed, which can be attributed to the formation of a thicker GeOX layer. On the other hand, when SPAO is performed after the deposition of both the high-k layers, higher D
it was observed suggesting that a thinner GeOX layer formation. Time zero dielectric breakdown (TZDB) characteristics indicate that plasma exposure after and in between AlO/ZrO2 deposition enhances the dielectric quality by film densification due to plasma exposure. It was demonstrated that improved dielectric and interface quality can be achieved when ALD-AlO/ZrO2 gate stacks were exposed to SPAO.
Study of Electrostatics and Transport Properties of Multigate Graded Nanowire Channel MOSFETs
Authors: Khosru Quazi D. M. , Khan Saeed Uz Zaman , Datta Kanak
Published: May 2016

In this work, we have studied the electrostatics and ballistic transport characteristics of a multigate MOSFET structure with axially composition graded InGaAs channel. Wave-function penetration and other quantum mechanical effects were considered, along with the effects of strain on the graded heterojunction. Schrödinger and Poisson’s equations were solved numerically using FEM method. Furthermore, we have studied effects of doping and depth variation of the graded layers on the threshold voltage and inversion gate capacitance of the device. The transport performance parameters extracted from the simulation revealed excellent on and off state transport performance of the graded device with an on-off current ratio of 107, Drain Induced Barrier Lowering of 43.79 mV/V, Subthreshold Swing of 61.37 mV/dec.
Determination of Antiphase Domain Boundary Annihilation Rate in GaAs on Si(001) and the Influence of MOCVD Growth Temperature
Authors: Barrett Caleb Shuan Chia , Martin Thomas Patrick , Bao Xin-Yu , Martin Patrick , Sanchez Errol , Jones Kevin Scott
Published: May 2016

The effect of growth temperature on the annihilation of antiphase domain boundaries (APBs) in GaAs grown on 300 mm Si(001) wafers via an industrial III-V metal organic chemical vapor deposition (MOCVD) tool is examined. Samples were grown with identical low temperature nucleation layers to set the APB density before growth of bulk layers at varied temperature. The APB annihilation rate with respect to GaAs film thickness is determined by profiling the APB density in the samples as a function of depth using a combination of chemical etchants. It is found that higher bulk growth temperatures enhance the annihilation of APBs. The increase in APB annihilation rate must be facilitated by a greater portion of APBs kinking from {110} type planes to higher-index planes such as {111} or {112}. The temperature dependence of APB annihilation indicates that there is an associated activation energy for the kinking of APBs.
Investigation of Nucleation and Intermixing at Hetero-Interface in III-Nitride-4H-SiC Structures
Authors: Enck Ryan Wade , Sampath Anand V , Chung Roy , Knorr Daniel B , Garrett Gregory A , Reed Meredith L
Published: May 2016

III-Nitride/SiC heterostructure devices are a promising approach for improving the performance of SiC devices such as bipolar transistors and avalanche photodiodes. However, the performance of these devices should critically depend on the properties of the hetero-interface that will likely lie within an active region of the device and impact carrier transport. Importantly, intermixing at the hetero-interface can effect doping profiles in these structures as constituent atoms of each semiconductor act as a dopant in the other. In this paper we explore the impact of in situ substrate preparation and migration enhanced epitaxy (MEE) on the nucleation and impurity concentration of thin AlN films grown by plasma-assisted molecular beam epitaxy on 4H-SiC. The surface morphology of the samples were examined by atomic force microscopy and the composition of the films were studies by secondary ion mass spectroscopy (SIMS) and depth profiling x-ray photoemission spectroscopy (XPS). The MEE approach promotes the nucleation of AlN growth on SiC in a 2D mode while suppressing the migration of Al into SiC. Active N that leaks around the closed shutter during in-situ preparation prevents the nucleation of AlN in a 2D growth mode at lower substrate temperatures that is attributed to GaN island formation at the hetero-interface.
GaN MIS-HEMT with Low Dynamic ON-Resistance Using SiON Passivation
Authors: Liu Shih Chien , Huang Chung Kai , Chang Edward Yi
Published: May 2016

An effective SiON passivation with high density of positive fixed charges for GaN MIS-HEMTs is demonstrated. The positive fixed charges at the SiON/AlGaN interface effectively reduce the surface potential and expand the quantum well below the Fermi level, thus improving the device performance. The GaN MIS-HEMT with SiON demonstrated a high maximum drain-source current density (IDS,max) of >1 A/mm, a breakdown voltage of 750 V at a drain leakage current of 1 μA/mm, and a well transfer characteristics. The dynamic ON-resistance only increased slightly under a high quiescent bias of 100 V.
Growth of GaN/InGaN Films and Heterostructures Via Super-Atmospheric MOCVD
Authors: Krause John Robert , Stokes Edward Brittain
Published: May 2016

In the interest of improving crystalline quality and optical performance of MOCVD grown semiconductors a unique super-atmospheric reactor was designed and fabricated. This reactor has since been used to fabricate GaN/InGaN multi-quantum-well heterostructures under superatmospheric growth conditions. The resulting samples were analyzed through in-situ and ex-situ measurements.
(Invited) New Directions in GaN Photonics Enabled by Electrochemical Processes
Authors: Zhang Cheng , Yuan Ge , Xiong Kanglin , Park Sung Hyun , Han Jung
Published: May 2016

We have developed a novel conductivity based selective electrochemical etching to introduce nanometer sized pores into GaN. The nanoporous (NP) GaN can be considered as a new form of GaN with an unprecedented tunability in optical index. The advantages of NP-GaN for both edge-emitting laser diodes and vertical surface-emitting laser diodes (VCSEL) are subsequently exhibited.
Mechanical Analysis of Stretchable AlGaN/GaN High Electron Mobility Transistors
Authors: Tompkins Randy P. , Mahaboob Isra , Shahedipour-Sandvik Shadi , Lazarus Nathan
Published: May 2016

Adding waves or kinks to a conductor is a well-known method for relieving strain in stretchable systems. Although transistors and other devices made of brittle semiconductors have also been demonstrated, the effects of the crystalline anisotropy on the mechanical behavior has not been previously investigated. In this work, a numerical solver is used to simulate the peak stresses in silicon and gallium nitride embedded within soft silicone in common stretchable geometries. As expected from other work, adding waves reduces peak stress by more than a factor of ten. The effects of in-plane rotations were then investigated. In the typical [0001] growth direction for gallium nitride, the matrix is rotationally invariant, with no variation in peak stress upon rotation about the [0001] direction. For silicon, however, peak stress was found to vary by as much as 17 percent for rotation about the [001] direction.
An Multifuntional Micro-Pump for Sample Selection Based on Low-Voltage Electrokinetic Mechanism
Authors: Liao Yan-Jie , Lin Shiang-Chi , Gao Chia-Hong , Lin Chih-Ting
Published: May 2016

Due to the need of developing point-of-care testing, measurement devices should be small in size and light in weight. In tradition, the measurement device usually need an additional bulky pump to inject the sample into it. So the requirement of additional bulky pump is the problem to be overcome when developing POCT device. In our work, the result successfully showed a multifunction micro-pump with low power consumption. This micro-pump possesses two critical functions, which are sample pumping and particle trapping. The most important of all is this micro-pump is quiet small within a total area of 1mm2, which means it has the potential to be integrated with corresponding sensors or other measurement devices. In summary, this micro pump is a good choice to develop as one part of POCT device with sample pumping and particle trapping (selecting) functions.