bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel Cross-Linked Ortho-Carborane and Ortho-Carborane:Y (Y=1,4-Diaminobenzene, Pyridine, Benzene) Polymer Films: A New Class of Carborane-Based Materials with Tunable Electronic Structure
Authors: Pasquale Frank L , James Robinson , Welch Raymond , Echeverria Elena , Dowben Peter A. , Kelber Jeffry A.
Published: May 2013

A new class of semi-conducting boron carbide polymers has been formed from cross-linking of ortho-carborane (o-B10C2H12) or o-B10C2H12 in the presence of aromatic compounds (Y =1,4-diaminobenzene, pyridine, and benzene) to form B10C2HX and B10C2HX:Y, respectively. Core and valence band photoemission and molecular orbital calculations indicate that cross-linking of o-B10C2H12 results in site-specific bonding between boron sites opposite carbon sites on the carborane icosahedra. This site specificity is retained when cross-linking o-B10C2H12 in the presence of aromatic linking units; the linking units insert themselves between carborane icosahedra. This insertion results in bonding between boron sites opposite carbon sites in the carborane icosahedra to carbon sites on the aromatic moieties. B10C2HX:Y films exhibit shifts in the valence band maximum from -4.3 eV (i.e. 4.3 eV below the Fermi level) for B10C2Hx, to -2.6 eV, -2.2 eV and -1.7 eV for Y = benzene, pyridine, or 1,4-diaminobenzene, respectively. States near the top of valence band correspond to states localized on the linking unit. Films formed by plasma-enhanced chemical vapor deposition of o-B10C2H12 are p-doped, and such films show excellent rectifying characteristics when deposited on n-type Si--extremely promising for neutron detection and other device applications.
Interface Trap Redistribution and Deep Depletion Behavior of Non-Planar MOS with Ultra Thin Oxide Grown by Anodic Oxidation
Authors: Tseng Po-Hao , Hwu Jenn-Gwo
Published: May 2013

Redistribution of interface trap capacitance (Cit) and deep depletion (D.D.) behavior was observed in non-planar substrate MOS capacitors with ultra thin oxides grown by anodic oxidation (ANO). We find the D.D. electrical characteristics between the non-planar and planar samples are different. The minority carrier crowding induced low frequency effect and corner E-field crowding induced D.D. was observed in non-planar substrate MOS capacitors. Moreover, the deep depletion behavior of non-planar sample after constant voltage stress (CVS) was also explored. The non-planar devices exhibit significant two peaks distribution in Cit after CVS due to multiple surfaces effect. It was found that the multiple surfaces effect induces additional interface trap of acceptor-like. However, the interface trap characteristic of planar sample is mainly donor-like.
Effect of Composition Rate on Erbium Silicide Work Function on Different Silicon Surface Orientation
Authors: Tanaka Hiroaki , Teramoto Akinobu , Motoya Tsukasa , Sugawa Shigetoshi , Ohmi Tadahiro
Published: May 2013

Electrical and physical properties of ErSix on n-type Si(100) (111) and (551) surfaces are reported. The ErSix density affects the work function of ErSix. A controlling the composition ratio of Er and Si is a key parameter for a reducing contact resistance for high performance MISFETs. These silicidation reactions are very important to develop the high current drivability devices using any surface orientation.
Experimental Observation of Poole-Frenkel Saturation in an Ultrathin Tantalum Oxide Capacitor Structure
Authors: Lau Wai Shing
Published: May 2013

In this paper, the author points out that Poole-Frenkel (P-F) saturation can be experimentally observed in ultrathin tantalum oxide capacitors. Factors why P-F saturation has been difficult to observe experimentally will be discussed. P-F saturation has not been successfully observed in thick tantalum oxide capacitors. Using an annealing process at a temperature just below the crystallization temperature seems to be helpful. In addition, TiN gate seems to be much better compared to Al gate. N2O is superior to O2 as the annealing ambient.
Growth and Characterization of Single Crystalline Ga-doped ZnO Thin Films Using Metal-Organic Chemical Vapor Deposition
Authors: Horng Ray-Hua , Huang Chiung-Yi , Yin Chen-Yang , Ravadgar Parvaneh , Wuu Dong-Sing
Published: May 2013

Ga-doped ZnO (GZO) materials with high thermal stability and high carrier mobility are essential for the development of transparent conductive electrodes (TCE). We changed the amount of Ga doping into ZnO thin films to decrease the electric resistivity of ZnO thin film. The GZO films have been grown on c-plane sapphire substrate by metal-organic chemical vapor deposition (MOCVD). It was found that GZO films transparency rate can reach more than up 90 %, and up to 10-4 Ω-cm resistivity magnitude. The results show that GZO transparent conductive films were thermal annealing treatment under nitrogen ambient at for 2 minutes by rapid thermal annealing. And Ga doping into the ZnO is about to 1020 cm-3. It reveals that the GZO can significant improve the conductivity and increase the carrier concentration.
Polycrystalline CdTe PN Diode Formed by Au and Al Diffusion
Authors: Kim Jin Sung , Jeon Pyo Jin , Lee Junyeong , Kim Min Je , Lee Dong-jin , Kim Tae-woo , Song Pung Keun , Lee Geon-Hwan , Im Seongil
Published: May 2013

This paper represents our effort on the polycrystalline CdTe PN junction device which used thermal evaporation for 270 mm-thick thick CdTe on glass substrate followed by respective thermal diffusion of Au and Al for p and n doping. And scannning electron microscopy and X-ray diffraction techniques were employed to investigate the substrate heating effect on CdTe crystalline quality.
Metal Catalyzed Porous n-type GaN Layers: Low Resistivity Ohmic Contacting and Single-Step MgO/GaN Diode Formation
Authors: Bilousov O V , Carvajal Joan J , Drouin D , Vilalta A , Ruterana P , Pujol M C. , Mateos X. , Díaz F , Aguiló M , O'Dwyer Colm
Published: May 2013

Porous GaN crystals have been successfully grown and electrically contacted simultaneously on Pt- and Au-coated silicon substrates as porous crystals and as porous layers. By the direct reaction of metallic Ga and NH3 gas through chemical vapor deposition, intermetallic metal-Ga alloys form at the GaN-metal interface, allowing vapoursolid- solid seeding and subsequent growth of porous GaN. Currentvoltage and capacitance-voltage measurements confirm that the intermetallic seed layers prevent interface oxidation and give a highquality reduced workfunction contact that allows exceptionally low contact resistivity. Additionally, the simultaneous formation of a lower workfunction intermetallic permits ohmic electron transport to n-type GaN grown using high workfunction metals that best catalyze the formation of porous GaN layers and may be employed to seed and ohmically contact a range of III-N compounds and alloys for broadband absorption and emission. Additionally, we show how a porous GaN rectifying diode can be formed by oxidatively crystallizing Mg typically employed for p-doping GaN, as a layer formed under porous structure resulting in a high-k polycrystalline MgO dielectric.
Preparation of Substrates Intended for the Growth of Lower Threading Dislocation Densities within Nitride Based UV Multiple Quantum Wells
Authors: Conroy Michele Ann , Petkov Nikolay , Li Haoning N , Sadler Thomas C , Zubialevich Vitaly , Holmes Justin D. , Parbrook Peter J
Published: May 2013

In this study a variety of nano-patterning techniques were applied to III-N device fabrication. A block co-polymer/metal oxide novel surface texturing method was utilised to achieve a long ranged ordered template. Nano-sphere lithography was also applied to UV multiple quantum well (MQW) structural growth using a silica nanoparticle monolayer as the mask. The monolayer was produced by a self-assembly technique without the need for either a spin coater or Langmuir-Blodgett trough resulting in a low cost arrangement. Using these nano-sized masks allows for the production of nano-rods in a much simpler method than previously used techniques. For comparison nano-rods were made by electron beam lithography at various diameters and lengths for a comprehensive investigation of crystal defects, in particular threading dislocations (TDs).
A Novel Detection of Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs) for HIV-1 with AlGaN/GaN High Electron Mobility Transistors
Authors: Kang Yen-Wen , Lee Geng-Yen , Chyi Jen-Inn , Hsu Chen-Pin , Hsu You-Ren , Huang Chih-Cheng , Ren Fan , Wang Yu-Lin
Published: May 2013

As acquired immunodeficiency syndrome (AIDS) caused by HIV-1 (human immunodeficiency virus type 1) has been in the top 10 leading causes of death for recent years, there have been many promising treatment discovered. One of the treatments is by taking non-nucleoside reverse transcriptase inhibitors (NNRTI) to suppress the activity of the HIV-1. The binding affinity of NNRTI to the reverse transcriptase (RT) of HIV-1 is an important factor determining the efficiency of the drug performance. The HIV-1 RT immobilized AlGaN/GaN high electron mobility transistors (HEMTs) were used to find the dissociation constant of NNRTIs. Comparing to conventional drug analyzing, HEMTs assisting experiments are much faster in processing time and lower cost.
Strong Visible Light Emission from Zinc-Blende InGaN/GaN Pn Junction on Silicon Substrate
Authors: Nishimura Suzuka , Hirai Muneyuki , Nagayoshi Hiroshi , Terashima Kazutaka
Published: May 2013

The zinc-blende GaN (c-GaN) crystals on Si(100) substrates were successfully grown by metal organic chemical vapor deposition (MOCVD) technique with BP buffer layer. The cubic phase purity was higher than 93%. We also grew InGaN single quantum well (SQW) on n-type c-GaN and cover with p-type c-GaN to make pn junction. When the electric current passed through the pn junction, surprisingly strong light was emitted from the junction.
Biochemical Sensors: Comparison of the Performance of TiO2, SnO2:F and ITO Used as the Main Sensing Element
Authors: Fernandes Jessica Colnaghi , Torres Katia Albertin Franklin , Silva Guilherme Oliveira , Heimfarth Tobias , Carreño M.N. P. , Pereyra Ines , Mulato Marcelo
Published: May 2013

Development of new biosensors has extremely importance in medicine. The main targets are the miniaturization of these devices, less invasive methods to the patient, high sensitivity and fast response. The deposition method to produce the oxide thin films has great influence on films properties, to be used as sensitivity layer of a biosensor. Several oxide materials have been developed to find the higher sensitivity, close to Nernst equation and fast response. Titanium oxide, fluorine-doped tin oxide and indium tin oxide are compared using different deposition techniques. The higher sensitivity was reached using fluorine-doped tin oxide prepared by chemical vapor deposition (about 58 mV/pH).
Simulation of Thermal Effects on Hydrogen-Terminated Diamond MOSFETs
Authors: Zhou Xi , Williams Frances , Albin Sacharia , Sundaram Kalpathy B
Published: May 2013

The DC characteristics of hydrogen-terminated diamond (HTD) MOSFETs are simulated in the temperature range from 140 to 500K. The temperature-dependent parameters, such as band gap width, intrinsic/extrinsic carrier density, hole mobility and hole saturation velocity, are calculated and compared with measured data. The simulated output/transfer characteristics show good agreement with experiments, and the maximum drain current shows smaller thermal variation than the low-field mobility does, which is due to the existence of transverse field during device operation. In addition, the pinch-off voltage is found to change linearly with temperature and the temperature coefficient is as small as 0.26mV/K. The thermodynamic simulation reveals that for HTD MOSFETs, the lattice temperature will increase only 30K when the device is operated at a current density as high as 1A/mm.
Nano-Porous TiO2 Photoanode for Higher Electrolyte Accessibility Using Microfibrillated Cellulose as a Sacrificial Template
Authors: Li Yan , Drzal Lawrence T.
Published: May 2013

A novel method of fabricating a nano-channeled porous titania photoanode was developed by using micro-fibrillated cellulose as a template for formation of a sol-gel TiO 2 precursor to enhance electrolyte penetration. The cellulose was homogenized and consists of microfibers with a 30 nm-diameter and several microns in length uniformly suspended in either water or isopropanol, depending on the fabricating method. In the non-aqueous environment, hydrolysis and condensation rates were greatly reduced and an ultra thin film around 500nm was prepared on glass substrate. In the aqueous solution, a 3-5um thick film was made by liquid phase deposition and doctor-blade. Cellulose was removed by calcination resulting in the formation of the porous, channeled structure. Scanning electron microscopic images of focused ion beam sections confirm the ordered porous, channeled structure. Analysis with Raman spectroscopy, X-ray diffraction, and UV-Vis spectroscopy, verify the anatase phase and the surface properties of the photoanode.
Various Schottky Contacts of AlGaN/GaN Schottky Barrier Diodes (SBDs)
Authors: Ahn Woojin , Seok Ogyun , Ha Min-Woo , Kim Young-Shil , Han Min-Koo
Published: May 2013

We have proposed and fabricated high performance of AlGaN/GaN Schottky Barrier Diodes (SBDs) with various Schottky contact. The breakdown voltage of proposed SBDs with the TaN and ITO Schottky contact deposited by RF sputtering method was increased compared to the widely used Ni/Au Schottky contact. The extracted Schottky barrier height (SBH) of TaN and ITO was 0.62 eV and 0.54 eV respectively while that of Ni/Au was 0.51 eV. The reverse blocking characteristics such as the leakage current and breakdown voltage was improved by TaN and ITO Schottky contact due to its high SBH. However, forward current of TaN and ITO Schottky contact was less than that of Ni/Au Schottky contact. The TaN Schottky SBDs achieved highest breakdown voltage of 605 V and ITO Schottky SBDs achieved 472 V. On the contrary, the breakdown voltage of Ni/Au Schottky SBDs exhibits 335 V.
Surface Degradation of GaN after Thermal Processes
Authors: Ha Min-Woo , Seok Ogyun , Ahn Woojin , Han Min-Koo
Published: May 2013

The effects of thermal process on the surface degradation of GaN were investigated. The GaN was grown on Si(111) substrate and thermally treated. When the temperature of thermal processes increased, the grain boundary expanded and pits generated as a result of the decomposition. The band-edge emission intensity in the photoluminescence spectra was increased by thermal processes. The deep-level emission centered at about 2.2 eV suppressed after thermal processes. We estimate that they were caused by the increase of band-edge emission intensity or the surface decomposition associated with impurity-related recombination in GaN. The full-width at half-maximum of (0002) X-ray rocking curve did not change significantly before and after the thermal processes. This indicated that the surface decomposition of our thermal processes did not affect the crystal quality. A side effect of decomposition owing to the high-temperature process should be considered in the fabrication of GaN-based electronic devices.
RF-Sputtered HfO2 Gate Insulator in High-Performance AlGaN/GaN MOS-HEMTs
Authors: Seok Ogyun , Ahn Woojin , Ha Min-Woo , Han Min-Koo
Published: May 2013

We have proposed and fabricated AlGaN/GaN metal-oxide-semiconductor-high-electron-mobility transistors (MOS-HEMTs) on Si substrate employing RF-sputtered HfO2 gate insulator for a high breakdown voltage. The HfO2 sputtering conditions such as a sputtering power and working pressure have been optimized in order to improve reverse blocking characteristics. We obtained the high breakdown voltage of 1524 V, the low drain leakage current of 67 pA/mm when VDS= 100 V and VGS= –10 V, and on/off current ratio of 2.37×1010 at sputtering power of 50 W and working pressure of 3 mTorr. In addition, we also discussed the mechanism of breakdown voltage improvement and investigated HfO2/GaN interface in the proposed devices by measuring the leakage current, capacitance-voltage characteristics, and X-ray diffraction (XRD).
Effects of Composition Ratio on Solution-Processed InGaZnO Thin-Film Transistors
Authors: Lee Jeong-Soo , Song Seung-Min , Lee Soo-Yeon , Kim Yong-Hoon , Kwon Jang-Yeon , Han Min-Koo
Published: May 2013

We fabricated solution-processed IGZO TFTs with various composition ratio of precursors according to the contents of In, Ga, and Zn. Threshold voltage of solution-processed IGZO TFTs was -0.43 V, 3.86 V, and 11.12 V when the composition ratio was varied by 7:1:2, 6:3:1, and 5:1:4, respectively. Saturation mobility of solution-processed IGZO TFTs was 1.4 cm2/V∙sec, 0.84 cm2/V∙sec, and 0.3 cm2/V∙sec with the composition ratio of 7:1:2, 6:3:1, and 5:1:4 respectively. When In composition ratio increased, the threshold voltage decreased and saturation mobility increased because of the increase of electron concentration. When Ga composition ratio increased, the off-current was decreased because of the suppression of formation of oxygen vacancies. When Zn composition ratio increased, the hysteresis was decreased because of the reduction of interstitial states between channel and insulator.
(Invited) The Materials Integration of Ge and InxGa1-X As on Si Template for Next Generation CMOS Applications
Authors: Chang Edward Yi , Tang Shih Hsuan , Lin Yueh-Chin
Published: May 2013

Lately, the semiconductor industry has paid a lot of attentions to the III-V compound semiconductor materials such as InSb, InxGa1-xAs for next generation CMOS applications, because these materials have significantly higher carrier mobility than silicon. For example, the electron mobility of InAs could reach 20000 cm2V-1s-1. High-speed devices such as quantum-well field-effect transistors (QWFETs) made from these III-V materials have demonstrated very low gate delay time. However, hole mobility for III-V materials are very low in general, some are even lower than the hole mobility of Si. So, it is important to look for a proper material with high hole mobility as p-channel FETs for future complementary CMOS architecture. Since Ge has a much higher bulk hole mobility (mh =1900 cm2/Vs) as compared to GaAs (mh = 400 cm2/Vs), Ge is suitable as p type channel material. Due to the small lattice mismatch (~0.08%) between GaAs and Ge, the integration of Ge with GaAs is comparable easy as compared to grow on Si , therefore thick Ge film can be grown as channel on GaAs substrates with very low defect density and integrate with InxGa1-xAs devices as a CMOS structure. In this talk, the growth of high quality Ge film on GaAs substrate by ultra high vacuum chemical vapor deposition (UHVCVD) and high quality InAs material on Ge/SiGe/Si template grown by molecular beam epitaxy (MBE) will be particularly reported. By the observation of XRD and AFM, both Ge film grown on GaAs material and InAs grown on Si substrates demonstrate high crystallinity and good surface morphology. The developed epitaxial materials systems including Ge on GaAs and InAs on Si are useful for future III-V/Ge/Si integration for next generation high speed low power CMOS application as well as for RF/digital mixed signal circuit application in the future.
(Invited) Strain-Enhanced Performance of Si-Nanowire FETs
Authors: Cassé Mikaël , Barraud Sylvain , Coquand Rémi , Koyama Masahiro , Cooper David , Vizioz C. , Comboroure C. , Perreau P. , Maffini-Alvaro V. , Tabone C. , Tosti L. , Barnola S. , Delaye Vincent , Aussenac Francois , Ghibaudo Gérard , Iwai H. , Reimbold Gilles
Published: May 2013

The combination of a multi-gate architecture and strain engineering is a promising way to fabricate high performance CMOS transistors. In this work we examine the effect of strain in Si nanowire Tri-Gate and Ω-Gate transistors. We present and discuss the results of electrical characterization of these advanced devices, with special attention to the carrier mobility, and to the piezoresistive coefficients
(Invited) Metal Gate/High-κ Dielectric Gate Stack Reliability; or How I Learned to Live with Trappy Oxides
Authors: Linder Barry P. , Cartier Eduard A. , Krishnan Siddarth
Published: May 2013

Over the last couple of scaling generations the gate stack in leading edge technology has migrated from Poly-Si and SiON to a metal gate with a bi-layer of a Hafnium based dielectric with a SiON interlayer (IL). This switch yielded immediate gains in gate leakage (Ig) and reliability, allowing a thinning of the inversion thickness (tinv) from ~20Å to less than 14Å. Even though gate length scaling and performance would drive further thinning of the dielectric stack, reliability considerations limit this. Understanding the fundamental reliability mechanisms enables mitigation with process changes and an optimization of reliability, performance, and operating voltage (Vmax). This paper will explore the main reliability mechanisms that are limiting scaling and the processes that improve reliability. Furthermore, the relationship between device level reliability and circuit reliability will be broached with ring oscillator data that shines light on the dominant reliability mechanism limiting Vmax.
Impact of Lanthanum on Positive-Bias Temperature Instability – Insight from First-Principles Simulation
Authors: Gu Chenjie , Ang Diing Shenp
Published: May 2013

The impact of lanthanum (La) on positive-bias temperature instability (PBTI) is examined via first-principles simulation of the electronic properties of the oxygen vacancy (V
O) and vacancy-interstitial (V
O-Oi) paired defects in the hafnium dioxide (HfO2) gate dielectric. The purpose is to understand the recently reported retardation of PBTI recovery in La-doped HfO2 gate n-MOSFETs, indicating that La doping has made part of the stress induced electron trapping become more permanent. Simulation results show that the formation energy of both defects are significantly decreased by La doping, implying that these defects are more readily formed in the La-doped HfO2 as compared to the undoped counterpart. The higher density of V
O’s should increase PBTI effect, contrary to the experimental observation of a reduced PBTI effect. The discrepancy may be reconciled by the smaller gate current in the La-doped n-MOSFET, believed to be due to the larger tunneling barrier that results from La dipoles at the HfO2/SiO
x
interface. With a smaller gate current, electron trapping – the main mechanism of PBTI – is correspondingly reduced. But the trap state of V
O in the La-doped HfO2 remains as shallow as that in the undoped counterpart and could not account for the reduction in the PBTI recovery observed experimentally. On the other hand, the trap state of the V
O-Oi defect is found to be much deeper, and the greater ease of its formation in the La-doped HfO2 could explain the reduced PBTI recovery observed experimentally.
On the Evolution of Switching Oxide Traps in the HfO2/TiN Gate Stack Subjected to Positive- and Negative-Bias Temperature Stressing
Authors: Gao Yuan , Ang Diing Shenp , Gu Chen Jie
Published: May 2013

In this paper, evolution of switching oxide traps (SOTs) in the HfO2/TiN gate stack is examined under positive- and negative-bias temperature (PBT and NBT, respectively) stress. Charging and discharging of SOTs were sensed by repetitive stress/ relaxation cycling and the discharging of SOTs was quantified based on the extent of the threshold voltage shift recovery after a fixed relaxation interval. For both the PBT and NBT stress at a low oxide field (~5.5 MV/cm), the quantity of SOTs discharged is observed to be approximately constant, independent of the number of stress/relaxation cycles. At a higher oxide stress field (~7 MV/cm), however, the quantity of SOTs discharged is seen to decrease progressively with the number of stress/relaxation cycles. This observation implies that a part of the SOTs which can be discharged in earlier relaxation phases is no longer able to do so as the stress progresses. The reduction in recovery points to an increase of the emission times of the trapped charge arising probably from structural changes at the oxide defect sites. Although the evolution of SOTs under both stresses is broadly similar, differences are observed from the opposite gate-polarity relaxation study and stress-induced leakage current measurement. First-principles simulation shows that a defect model based on the oxygen vacancy alone could not explain the differences observed. An extended model involving both the oxygen vacancy and vacancy-interstitial defects is shown to be able to explain the similarities as well as differences observed under PBT and NBT stresses.
(Invited) Understanding the Role of Dopants in Transition Metal Oxide Dielectrics for Digital and Analog Resistive Switching
Authors: Long Branden , Mandal Saptarshi , Li Yibo , Chen Wenbo , El-Amin Ammaarah , Jha Rashmi
Published: May 2013

Resistive Random Access Memory (ReRAM) devices have gathered significant attention recently for high-density non-volatile data storage applications. However, there are several challenges that need to be addressed to take complete benefit of this enabling technology. This paper discusses the role of intentional doping in transition metal oxide dielectrics, particularly HfO2, and its implications on the device performance. Our studies indicate that Mg doped HfO2 based ReRAM devices require lower electroforming voltage compared to undoped HfO2 based ReRAM devices. The reduction in set/reset voltages was also achieved in ReRAM devices with Mg doped HfO2. Excellent bipolar switching and endurance characteristics were achieved demonstrating doping in HfO2 as a viable route for achieving the desired ReRAM characteristics.
Turning an SOI Into MEMS Devices for Optics and RF
Authors: Toshiyoshi Hiroshi
Published: May 2013

This paper reports a use of SOI wafers in various MEMS (microelectromechanical systems) applications in micro optics and radio frequency devices. SOI wafer was originally developed for integrated circuits of improved performances in terms of suppressed current leakage and stray capacitance. At the same time, SOI has been used a lot in the field of MEMS due to the readiness of use as a mechanical material. Microstructures of high aspect ratio and small footprint have been made relatively easily by using the recent DRIE (deep reactive ion etching) processes compared with the anisotropic etching in a liquid phase. Despite the simple layer structure of SOI, various mechanical and electrical topologies were possible by using an electrical interconnection between the layers via a stiction bar. As an example of DRIE-processed SOI MEMS devices, we show a vertical-comb drive actuator with an initial offset angle for optical scanners, MEMS with integrated high-voltage driver circuits, micro XYZ-stages with electrostatic actuators, and all silicon passive RF device using integrated SPDT (single-pole double throw) switches.
Atomic Scale Thickness Control of SOI Wafers for Fully Depleted Applications
Authors: Schwarzenbach Walter , Daval Nicolas , Barec Vincent , Bonnin Olivier , Acosta-Alba Pablo-Eduardo , Maddalon Catherine , Chibko Alexandre , Robson Timothy , Nguyen Bich-Yen , Maleville Christophe
Published: May 2013

Smart Cut® Technology has recently been moved forward to a performance that seemed impossible until just recently. FDSOI requirements demand a method to transfer an ultra-thin crystalline layer with near perfect uniformity. Silicon thickness variation across all UTBOX wafers has reached +/- 5 A all points all wafers, while at the same time roughness has been improved to reach 0.8 A 30x30 µm2 RMS. BOX is available over a wide range of thicknesses from 10 to 50nm, ready to satisfy all possible applications. Such development efforts have now passed process technology qualification [1] and provided a proven path for further node scaling [2]. This paper reports the latest achievements in state of the art thickness and roughness control, which is enabling very low variability for fully depleted devices today.
Operation of Lateral SOI PIN Photodiodes with Back-Gate Bias and Intrinsic Length Variation
Authors: Novo C. , Giacomini R. , Afzalian A. , Flandre D.
Published: May 2013

This paper presents an analysis of the operation of lateral thin-film SOI PIN photodiodes for the detection of short wavelengths. Experimental measurements were done varying the back-gate bias in order to point out the behavior of the device. The temperature influence was also analyzed in 300K to 500K range. In addition, by using two-dimensional numerical simulations, the intrinsic length (LI) was changed, with the purpose of predicting the performance of this photodetector in more advanced technologies.
Fin Dimension Influence on Mechanical Stressors in Triple-Gate SOI nMOSFETs
Authors: Bühler Rudolf Theoderich , Simoen E. , Agopian Paula Ghedini Der , Claeys C. , Martino J. A.
Published: May 2013

This work studies the SiGe SRB and tCESL strained triple-gate SOI nMOSFETs using experimental devices and also process and device numerical simulations. The transconductance and mobility are investigated and analyzed with the strain data obtained from process simulations, including the influence of the fin dimensions on the strain. The use of SiGe SRB and tCESL strain combined resulted in higher strain and higher maximum transconductance.
The Generation Rate Analysis of Different S/D Junction Engineering in Scaled UTBOX 1T-DRAM
Authors: Nicoletti T. , Sasaki K. R. A. , dos Santos S. D. , Martino J. A. , Aoulaiche M. , Simoen E. , Claeys C.
Published: May 2013

In this work, based on experimental data and confirmed by simulation results, the retention time degradation with channel length is demonstrated, as well as its correlation with the electric field, gate-induced-drain-leakage (GIDL) and the generation rate by band-to-band-tunneling (BTBT).
(Allesandro Volta Award Presentation) Facts and Challenges in the Electrochemistry and Wet Surface Chemistry of Silicon
Authors: Chazalviel Jean-Noel
Published: May 2013

Silica being insoluble in non-fluoride medium, anodic oxide films are readily formed on silicon. Dissolution of any oxide film in HF leaves a surface covered with hydrogen. Anodization in HF leads to the formation of porous silicon, the hydrogen coating staying present during the process. At higher potentials, electropolishing is observed, with the presence of a thin oxide layer on the surface. At still higher potentials, mesoporous oxide films are obtained. In non-aqueous media, trace amounts of water unavoidably lead to irreversible formation of a silica layer. In methanol a more stable behavior is obtained, due to chemical surface modification by grafting of methoxy groups. Other modifications of the silicon surface include the formation of covalent Si-C bonds, which holds promises for applications, especially sensors. In the near future, challenges in silicon electrochemistry include a better understanding of several fundamental issues, and also improved preservation of the surface against oxidation.
(Invited) Semiconductor Nanostructures for Antireflection Coatings, Transparent Contacts, Junctionless Thermoelectrics and Li-Ion Batteries
Authors: Glynn Colm , Osiak Michal , McSweeney William , Lotty Olan , Jones Kim , Geaney Hugh , Quiroga-González Enrique , Holmes Justin D. , O'Dwyer Colm
Published: May 2013

Porous semiconductors structured top-down by electrochemical means, and from bottom-up growth of arrays and arrangements of nanoscale structures, are shown to be amenable to a range of useful thermal, optical, electrical and electrochemical properties. This paper summarises recent investigations of the electrochemical, electrical, optical, thermal and structural properties of porous semiconductors such as Si, In2O3, SnO2 and ITO, and dispersions, arrays and arrangements of nanoscale structures of each of these materials. We summarize the property-inspired application of such structurally engineered arrangements and morphologies of these materials for antireflection coatings, broadband absorbers, transparent contacts to LEDs that improve transmission, electrical contact and external quantum efficiency. Additionally the possibility of thermoelectric performance through structure-mediated variation in thermal resistance and phonon scattering without a p-n junction is shown through phonon engineering in roughened nanowires. Lastly, we show that bulk crystals and nanowires of p- and n-type doped Si are promising for use as anodes in Li-ion batteries.
TiO2 Nanotubes Formed in Aqueous Media: Relationship between Morphology, Electrochemical Properties and the Photoelectrochemical Performance for Water Oxidation
Authors: Acevedo-Peña Próspero , González Ignacio
Published: May 2013

The effect of voltage and electrolyte composition on the formation of TiO2 nanotube films over its morphology, semiconductor properties and photoelectrochemical performance for water oxidation was studied. TiO2 nanotube films were formed by potentiostatic anodization in 0.1 M H2SO4/0.05 M HF and 0.1 M H2SO4/0.05 M NH4F during 1 h at four different voltages. SEM images showed a more significant chemical attack when NH4F was employed, evidenced by larger tube diameters and thinner films. The semiconductor properties were altered by the nature of the counterEion utilized during film growth, obtaining films with a higher density of donor and less positive flat band potential in NH4F electrolytes. The films formed in NH4F showed higher photopotentials and photocurrent related to the modification of their morphology and semiconductor properties; attaining a maximum at formation voltage of 15 V.
Evidence of Phosphazene Steps Formation on InP by Cyclic Voltammetry Studies and XPS Analyses in Liquid Ammonia (-55°C)
Authors: Njel Christian , Gonçalves Anne-Marie , Aureau Damien , Mercier Dimitri , Etcheberry Arnaud
Published: May 2013

In liquid ammonia (-55°C), a stable phosphazene like film has been already revealed on InP. This work reports, for the first time, the evidence of different stages of this film on InP in this relevant non aqueous solvent. These results were carried out by a fully coupled approach with cyclic voltammetry, capacitance measurements and XPS analyses.
Preliminary Investigations of Ta Surface Chemistry in Aqueous Solutions of TeO2, and the Possible Formation of TaTe2
Authors: Tsang Chu F. , Kim Youn-Geun , Gebregziabiher Daniel , Stickney John L.
Published: May 2013

Reductive removal of Ta oxide electrochemically was studied using Cyclic Voltammetry (CV), in-situ scanning tunneling microscopy (EC-STM), and X-ray photoelectron spectroscopy (XPS). From CVs, it was shown that the longer a Ta electrode was maintained at negative potentials in excess of -1.5 V, the more surface oxide was reduced, as evidenced by increases in hydrogen evolution. Atomically-resolved EC-STM images were obtained after reduction at -1.8 V, and then imaging at -1.0 V. The efficacy of using Te to passivate the Ta surface was also investigated, and Te appeared to suppress oxide formation, as evidenced by EC-STM, CVs and XPS. Images of the Ta surface in a TeO2 solution suggested the formation of TaTe2 at the surface.
Anion Exchange Membranes for Vanadium Redox Flow Batteries
Authors: Chen Dongyang , Hickner Michael A. , Agar Ertan , Kumbur Emin Caglan
Published: May 2013

Cross-linked quaternary ammonium functionalized Radel membranes with a high degree of functionalization (DF) were synthesized and evaluated in a vanadium redox flow battery. The permeation of vanadium cations through this type of anion exchange membrane was reduced significantly compared to sulfonated ion exchange membranes, while the ion conductivity of the AEM was low. Increasing the DF increased the ion conduction and crosslinking endowed mechanical strength in water by restricting swelling. However, crosslinking decreased the ion conductivity of the membrane, which offset the benefit of increasing the DF and the very low vanadium permeation. The resulting cell performance was similar to that of N212.
Pathogenic and protective role of macrophages in kidney disease
Authors: Cao Qi , Wang Yiping , Harris David C. H.
Published: May 2013

Macrophages (MΦ) are located throughout kidney tissue, where they play important roles in homeostasis, surveillance, tolerance, and cytoprotection. MΦ are highly heterogeneous cells and exhibit distinct phenotypic and functional characteristics depending on their microenvironment and the disease type and stage. Recent studies have identified a dual role for MΦ in several murine models of kidney disease. In this review, we discuss the pathogenic and protective roles of the various MΦ subsets in experimental and human kidney diseases and summarize current progress toward the therapeutic use of MΦ in kidney diseases.
Dry eye modifies the thermal and menthol responses in rat corneal primary afferent cool cells
Authors: Kurose Masayuki , Meng Ian D.
Published: May 2013

Dry eye syndrome is a painful condition caused by inadequate or altered tear film on the ocular surface. Primary afferent cool cells innervating the cornea regulate the ocular fluid status by increasing reflex tearing in response to evaporative cooling and hyperosmicity. It has been proposed that activation of corneal cool cells via a transient receptor potential melastatin 8 (TRPM8) channel agonist may represent a potential therapeutic intervention to treat dry eye. This study examined the effect of dry eye on the response properties of corneal cool cells and the ability of the TRPM8 agonist menthol to modify these properties. A unilateral dry eye condition was created in rats by removing the left lacrimal gland. Lacrimal gland removal reduced tears in the dry eye to 35% compared with the contralateral eye and increased the number of spontaneous blinks in the dry eye by over 300%. Extracellular single-unit recordings were performed 8–10 wk following surgery in the trigeminal ganglion of dry eye animals and age-matched controls. Responses of corneal cool cells to cooling were examined after the application of menthol (10 μM–1.0 mM) to the ocular surface. The peak frequency of discharge to cooling was higher and the cooling threshold was warmer in dry eye animals compared with controls. The dry condition also altered the neuronal sensitivity to menthol, causing desensitization to cold-evoked responses at concentrations that produced facilitation in control animals. The menthol-induced desensitization of corneal cool cells would likely result in reduced tearing, a deleterious effect in individuals with dry eye.
Proportional spike-timing precision and firing reliability underlie efficient temporal processing of periodicity and envelope shape cues
Authors: Zheng Y. , Escabí M. A.
Published: May 2013

Temporal sound cues are essential for sound recognition, pitch, rhythm, and timbre perception, yet how auditory neurons encode such cues is subject of ongoing debate. Rate coding theories propose that temporal sound features are represented by rate tuned modulation filters. However, overwhelming evidence also suggests that precise spike timing is an essential attribute of the neural code. Here we demonstrate that single neurons in the auditory midbrain employ a proportional code in which spike-timing precision and firing reliability covary with the sound envelope cues to provide an efficient representation of the stimulus. Spike-timing precision varied systematically with the timescale and shape of the sound envelope and yet was largely independent of the sound modulation frequency, a prominent cue for pitch. In contrast, spike-count reliability was strongly affected by the modulation frequency. Spike-timing precision extends from sub-millisecond for brief transient sounds up to tens of milliseconds for sounds with slow-varying envelope. Information theoretic analysis further confirms that spike-timing precision depends strongly on the sound envelope shape, while firing reliability was strongly affected by the sound modulation frequency. Both the information efficiency and total information were limited by the firing reliability and spike-timing precision in a manner that reflected the sound structure. This result supports a temporal coding strategy in the auditory midbrain where proportional changes in spike-timing precision and firing reliability can efficiently signal shape and periodicity temporal cues.
Long-term potentiation of synaptic transmission in the adult mouse insular cortex: multielectrode array recordings
Authors: Liu Ming-Gang , Kang SukJae Joshua , Shi Tian-Yao , Koga Kohei , Zhang Ming-Ming , Collingridge Graham L. , Kaang Bong-Kiun , Zhuo Min
Published: May 2013

The insular cortex (IC) is widely believed to be an important forebrain structure involved in cognitive and sensory processes such as memory and pain. However, little work has been performed at the cellular level to investigate the synaptic basis of IC-related brain functions. To bridge the gap, the present study was designed to characterize the basic synaptic mechanisms for insular long-term potentiation (LTP). Using a 64-channel recording system, we found that an enduring form of late-phase LTP (L-LTP) could be reliably recorded for at least 3 h in different layers of IC slices after theta burst stimulation. The induction of insular LTP is protein synthesis dependent and requires activation of both GluN2A and GluN2B subunits of the NMDA receptor, L-type voltage-gated calcium channels, and metabotropic glutamate receptor 1. The paired-pulse facilitation ratio was unaffected by insular L-LTP induction, and expression of insular L-LTP required the recruitment of postsynaptic calcium-permeable AMPA receptors. Our results provide the first in vitro report of long-term multichannel recordings of L-LTP in the IC in adult mice and suggest its potential important roles in insula-related memory and chronic pain.
Critical Pertussis in a Young Infant Requiring Mechanical Ventilation
Authors: Nataprawira Heda Melinda , Somasetia Dadang Hudaya , Sudarwati Sri , Kadir Minerva , Sekarwana Nanan
Published: May 2013

Pertussis may likely be misdiagnosed in its initial or catarrhal phase as a common respiratory infection. The earlier diagnosis of pertussis really depends on the capability of the medical professional especially in the first line public health services. The lack of awareness in diagnosis of severe pertussis as one of the causes of severe respiratory problems may likely misdiagnose pertussis as respiratory failure or even septic shock. In fact, pertussis may manifest as a critical pertussis which can be fatal due to the respiratory failure that require pediatric intensive care unit using mechanical ventilation. We reported a confirmed pertussis case of a 7-weeks-old female infant referred to our tertiary hospital with gasping leading to respiratory failure and septic shock requiring mechanical ventilation, aggressive fluid therapy, and antibiotics. Pertussis was diagnosed late during the course of illness when the patient was hospitalized. Improvement was noted after administering macrolide which gave a good response.Bordetella pertussisisolation from Bordet-Gengou media culture yielded positive result.
Obturator Hernia: A Rare Case of Acute Mechanical Intestinal Obstruction
Authors: Aydin Ibrahim , Yucel Ahmet Fikret , Pergel Ahmet , Sahin Dursun Ali
Published: May 2013

Obturator hernia is a rare type of pelvic hernia which generally occurs in elderly patients with accompanying diseases. Because it is difficult to diagnose before surgery, the morbidity and mortality rates for obturator hernia are high. The most common symptom is strangulation combined with mechanical intestinal obstruction.
A Stability Indicating Assay Method Development and Validation for the Frovatriptan Succinate Monohydrate by Using UV: A Spectrophotometric Technique
Authors: Verma Hitesh , Verma Surajpal , Singh Harmanpreet
Published: May 2013

A new simple, reliable, inexpensive, and accurate method was developed for the quantification of Frovatriptan Succinate Monohydrate in different physiological media at 244 nm in bulk and in tablet dosage forms. The developed method is an attempt to surpass the disadvantages associated with the reported methods, namely, less sensitive and tedious in usage for routine purposes. Beer’s law was followed over the range of 1.0 µg/mL to 4.5 µg/mL. Stability indicating assay method was developed and validated as per the ICH guidelines using various parameters, for example, accuracy, precision, limit of quantification, limit of detection, robustness, ruggedness, solution stability, recovery, forced degradation (hydrolysis, photo degradation, thermal degradation, and oxidation), and so forth. Percent relative standard deviation associated with all the parameters was less than 2, showing compliance with the acceptance criteria of ICH guidelines. The developed method was very sensitive as limit of quantification and limit of detection were found to be 0.025 µg/mL and 0.00625 µg/mL, respectively. Forced degradation studies of drug reveal good stability under the chosen experimental conditions.
Noncoding RNAs in Neurodegenerative Diseases
Authors: Rege Shraddha D. , Geetha Thangiah , Pondugula Satyanarayana R. , Zizza Claire A. , Wernette Catherine M. , Ramesh Babu Jeganathan
Published: May 2013

Noncoding RNAs are widely known for their various essential roles in the development of central nervous system. It involves neurogenesis, neural stem cells generation, maintenance and maturation, neurotransmission, neural network plasticity, formation of synapses, and even brain aging and DNA damage responses. In this review, we will discuss the biogenesis of microRNA, various functions of noncoding RNA's specifically microRNAs (miRNAs) that act as the chief regulators of gene expression, and focus in particular on misregulation of miRNAs which leads to several neurodegenerative diseases as well as its therapeutic outcome. Recent evidences has shown that miRNAs expression levels are changed in patients with neurodegenerative diseases; hence, miRNA can be used as a potential diagnostic biomarker and serve as an effective therapeutic tool in overcoming various neurodegenerative disease processes.
Ethoxyquin: An Antioxidant Used in Animal Feed
Authors: Błaszczyk Alina , Augustyniak Aleksandra , Skolimowski Janusz
Published: May 2013

Ethoxyquin (EQ, 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline) is widely used in animal feed in order to protect it against lipid peroxidation. EQ cannot be used in any food for human consumption (except spices, e.g., chili), but it can pass from feed to farmed fish, poultry, and eggs, so human beings can be exposed to this antioxidant. The manufacturer Monsanto Company (USA) performed a series of tests on ethoxyquin which showed its safety. Nevertheless, some harmful effects in animals and people occupationally exposed to it were observed in 1980’s which resulted in the new studies undertaken to reevaluate its toxicity. Here, we present the characteristics of the compound and results of the research, concerning, for example, products of its metabolism and oxidation or searching for new antioxidants on the EQ backbone.