bluuebunny/crossref_metadata_2025_split huggingface dataset:
Noise in Different Micro-bolometer Configurations with Silicon-Germanium Thermo-sensing Layer
Authors: Kosarev Andrey , Kosarev Andrey , Torres Alfonso J , Cosme Ismael 
Published: April 2011

ABSTRACTA recent interest in thermal detectors is due to plasma deposited materials with large temperature coefficient of resistance (TCR) and micro-machining technology for thermal isolation. Both are compatible with dominating Si CMOS technology that makes it possible developing device-on-chip configurations. In our previous works we have reported on the study of fabrication and characterization of single cell micro-bolometers based on silicon-germanium thermo-sensing films deposited by low frequency plasma [1-3]. Noise measurements are very important part of device characterization, which have been poorly reported in literature. Models proposed by present time for noise description in non-crystalline samples (either in films or in device structures) are still debated and no one can be considered as the only accepted. The goal of this work is to study experimentally noise spectral density in several configurations of micro-bolometers with silicon-germanium (a-SixGey:H) as thermo-sensing films. We studied four configurations: planar structure with a) a-SixGey, y=0.5, b) a-SixGeyBz:H, x=0.5, y=0.45 and z=0.05 ; c) x=0.5, y=0.5, z=0 and d)sandwich structure with x=0.5, y=0.5. These samples were characterized by SIMS (composition), FTIR (H-bonding and H content), conductivity measurements (σ(T), activation energy, TCR), current-voltage characteristics in dark and under illumination (responsivity). Noise spectral density (NSD) versus frequency S(f) was studied in the range of frequency f=1 to f=103 Hz under IR illumination modulated with this frequency and constant bias. The measurements were performed in vacuum chamber with P=10 mTorr. Generally S(f) dependence demonstrated three regions separated by two corner frequencies: fc1 and fc2: 1) f ≤ fc1 S1 α f -γ γ =0.15 to 0.5, 2) fc1 ≤ f ≤ fc2, S2 α f-γ γ = 0.7 to 1.34 and 3) f ≥ fc2 S3 const (f). Different samples studied showed different values of fc1, fc2 γ and S3. These noise characteristics observed experimentally are analyzed in comparison with data reported in literature and possible mechanisms for noise in the frequency regions studied are discussed.
Aligned-Crystalline Si Films on Glass
Authors: Findikoglu Alp T. , Ugurlu Ozan , Holesinger Terry G. 
Published: April 2011

ABSTRACTWe report structural and electronic properties of Aligned-Crystalline Si (ACSi) films on glass substrates. These films show enhanced majority carrier mobilities and minority carrier lifetimes with increasing crystallinity, i.e., with improving alignment and connectivity of the grains. A 0.4-μm-thick ACSi film with a total grain mosaic spread of 4.2° showed Hall mobility of 47 cm2/V.s for a p-type doping concentration of 1.9×1018 cm−3. A prototype n+/p/p+–type diode fabricated using a 4.2-μm-thick ACSi film showed minority carrier lifetime of ∼3.5 μs and estimated diffusion length of ∼30 μm in the p layer with a doping concentration of 5×1016 cm−3.
Links Between Etching Grooves Of Partial Dislocations And Their Characteristics Determined By TEM In 4H SiC
Authors: Ayoub Jean-Pierre , Texier Michael , Regula Gabrielle , Pichaud Bernard , Lancin Maryse 
Published: April 2011

ABSTRACTWe introduce defects into (1120) oriented highly N-doped 4H-SiC by surface scratching, bending and annealing in the brittle regime. Emerging defects at the sample surface are revealed by chemical etching of the deformed samples. The etch patterns are constituted of straight bulges and grooves exhibiting various topographical features. These etch figures correspond to the emergence of double stacking faults dragged by a pair of partial dislocations. In this paper, we discuss the links between the etch figure characteristics and the defect nature. Results obtained by optical and atomic force microscopy are completed by structural analysis of defects performed by transmission electron microscopy. Mobility of partial dislocations in 4H-SiC is discussed and correlated to their core composition and to the effect of the applied mechanical stress.
Influence of Growth Conditions and Substrate Properties on Formation of Interfacial Dislocations and Dislocation Half-loop Arrays in 4H-SiC(0001) and (000-1) Epitaxy
Authors: Tsuchida Hidekazu , Kamata Isaho , Kojima Kazutoshi , Momose Kenji , Odawara Michiya , Takahashi Tetsuo , Ishida Yuuki , Matsuzawa Keiichi 
Published: April 2011

ABSTRACTFormation of interfacial dislocations (IDs) and dislocation half-loop arrays (HLAs) and their appearance in 4H-SiC epi-wafers are investigated by X-ray topography and KOH etching analysis. Synchrotron reflection X-ray topography demonstrates the ability to image IDs and HLAs simultaneously and reveal their densities as well as spatial distributions in the epi-wafers. The vertical location of IDs in the epi-wafer is also examined by this technique. The influence of wafer warp, in-situ H2 etching prior to epitaxial growth, substrate off-angle as well as the growth face (Si-face and C-face) on the densities and spatial distributions of IDs and HLAs are discussed.
Stress Mapping of SiC Wafers by Synchrotron White Beam X-ray Reticulography
Authors: Zhang Ning , Chen Yi , Sanchez Edward , MacMillan Michael F. , Dudley Michael 
Published: April 2011

ABSTRACTSynchrotron white beam x-ray reticulography was used to quantitatively map the residual stress/strain in SiC wafers. The basic principle of our study is that there exists a relationship between the stress state in a crystal and the local lattice plane orientation and that this relationship can be exploited in order to determine the full strain tensor as a function of position inside the crystal. The theoretical background of the stress mapping using synchrotron white beam x-ray reticulography is introduced and it is based on the change of plane normal of the lattice plane due to the distortion associated with the residual strain. The stress mapping of a crystal region from a commercial 4H silicon carbide wafer has been studied using this technique and the results are discussed. This technique can in principle be used in any single crystal material.
Degradation of Majority Carrier Conductions and Blocking Capabilities in 4H-SiC High Voltage Devices due to Basal Plane Dislocations
Authors: Ryu Sei-Hyung , Zhang Qingchun , Fatima Husna , Haney Sarah , Stahlbush Robert , Agarwal Anant 
Published: April 2011

ABSTRACTThis paper presents the effect of recombination-induced stacking faults on the drift based forward conduction and leakage currents of high voltage 4H-SiC power devices. To show the effects, 10 kV 4H-SiC MPS (Merged PiN Schottky) diodes have been fabricated on a standard wafer and a low BPD (Basal Plane Dislocation) wafer, and their IV characteristics were evaluated before and after a forward bias stress, which resulted in minority carrier recombination and conductivity modulation in the drift epilayer of the diodes. After the stressing, the diode fabricated on standard wafer showed a significant increase in forward voltage drop, as well as a marked increase in leakage current, which were due to induction of stacking faults. The diode on the low BPD wafer showed very little change after the stress because the induction of stacking faults was minimized. Similar results were also observed on a 10 kV 4H-SiC DMOSFET. The results suggest that recombination-induced stacking faults are detrimental to all device types, and injection of minority carriers in majority carrier devices should be avoided at all times.
Scanning Spreading Resistance Microscopy For 3D-Carrier Profiling in FinFET-based Structures
Authors: Mody Jay , Eyben Pierre , Polspoel Wouter , Jurczak Malgorzata , Vandervorst Wilfried 
Published: April 2011

ABSTRACTJunction formation in FinFET-based 3D-devices is a challenging problem as one targets a complete conformal doping of the source/drain regions in order to produce equal gate-profile overlaps (and thus transistor behavior) on all sides of the fins. Due to the lack of predictive modeling for several of the doping strategies explored (plasma immersion, cluster implants, vapor phase deposition, etc…) it becomes difficult to correctly predict the performance of the devices and hence, accurate 3D-doping profile determination is desired. Although several dopant/carrier profiling methods exist with excellent one- or two-dimensional resolution and properties, there is an urgent need to extend these towards a quantitative three-dimensional geometry. In this work, we use scanning spreading resistance microscopy (SSRM) with dedicated FinFET test structure to obtain three-dimensional information from successive two-dimensional scanning spreading resistance maps. We also assess the validity of our methodology by comparing various sections along the fins which represent the variability due to the processing and measurement procedure.
Investigation of Platinum Silicide Schottky Barrier Height Modulation using a Dopant Segregation Approach
Authors: Breil Nicolas , Halimaoui Aomar , Dubois Emmanuel , Lampin Evelyne , Larrieu Guilhem , Godet Ludovic , Papasouliotis George , Skotnicki Thomas 
Published: April 2011

ABSTRACTThe role of the dopant activation on the segregation efficiency during the formation of platinum silicide (PtSi) is investigated in this paper. Using an implant before silicidation technique, we first demonstrate an important Schottky Barrier Height (SBH) modulation for As and B segregation. In the case of As, we highlight that an activation of the dopants before the silcidation does not impact the SBH modulation. On the contrary, an important impact of the dopant crystalline position is evidenced for Boron. Also, a comparison of conventional implant versus a PLAsma Doping (PLAD) highlights the suitability of the latter implantation tool for the SBH modulation. Those results are interpreted on the basis of SIMS depth profiling.
Infrared Semiconductor Laser Annealing Used for Formation of Shallow Junction
Authors: Sameshima Toshiyuki , Mizutani Yuta , Sano Naoki , Naito Masao 
Published: April 2011

ABSTRACTWe report continuous-wave (CW) infrared-semiconductor laser annealing of silicon implanted with boron atoms with assistance of diamond-like carbon (DLC) films as optical absorption layer in order to form shallow junctions. BF2 ions were implanted at 10 keV at doses of 1.5×1015 cm−2 thorough an 8-nm thick SiO2 layer. The effective boron dose implanted into silicon was 7.5c1015 cm−2 a half of the implantation dose. The initial boron distribution had a peak concentration of 6×1020 cm−3 at the silicon surface and a concentration of 1×1019 cm−3 at a depth of 27 nm. The samples were coated with 200-nm-thick DLC films. The samples were annealed by irradiation with a 940 nm continuous wave laser at 80 kW/cm2 with a beam diameter of 180 μm for 2.6 ms. Heat flow analysis estimated that the sample surface was heated to 1350°C for 1.5 ms by laser annealing. Laser annealing markedly reduced the sheet resistance to 531 Ω/sq. Boron atoms were almost completely activated with a carrier density close to the effective boron dose of 7.5×1014 cm−2. The in-depth profile of boron concentration hardly changed within 3 nm for laser annealing for 2.6 ms. The intermediate SiO2 layer effectively blocked carbon incorporation to a level below 1017 cm−3. These results show that the present laser annealing method is suitable to form shallow junction of a high dopant activation ratio. We will report low energy implantation of boron-cluster ions followed by the present infrared-semiconductor laser annealing in order to form a shallow junction with a depth less than 15 nm.
Optimization of Stressor Layers Created by ClusterCarbon™ Implantation
Authors: Sekar Karuppanan , Krull Wade A , Horsky Thomas N 
Published: April 2011

ABSTRACTSi:C layers are interesting candidates as stressor layers for NMOS transistors. Growth of such a Si:C layer has been realized by an expensive epitaxial growth process for devices to produce tensile strain in the channel, leading to enhanced mobility and device performance. Use of a monomer carbon ion implant in conjunction with a Ge pre-amorphizing implant (Ge-PAI) in Si is an alternative, lower cost approach to obtaining such SiC layers. This approach has not yielded desired device performance owing to low carbon substitutionality [C]sub, and also the presence of end-of-range (EOR) defects and large leakage currents due to the Ge-PAI implant. In this study we will show the formation of a Si:C layer using a ClusterCarbon approach that creates self-amorphization in Si thus avoiding an extra Ge-PAI implant step. We show that more than 2% substitutional carbon can be realized by using solid-phase-epitaxial-regrowth (SPER) and millisecond anneal. Si:C layers are characterized by using High Resolution X-ray Diffraction (HRXRD) and SIMS techniques.
Atomistic Simulation and Subsequent Optimization of Boron USJ Using Pre-Amorphization and High Ramp Rates Annealing
Authors: Singer Julien , Wacquant François , Villanueva Davy , Salvetti Frédéric , Laviron Cyrille , Cueto Olga , Rivallin Pierrette , Jaraíz Martín , Poncet Alain 
Published: April 2011

ABSTRACTThis study presents the use of atomistic process simulations to optimize p+/n ultra-shallow junctions fabrication process. We first bring to the fore that a high injection of interstitials close to the boron profile decreases the sensibility of boron diffusion to thermal budget. Preamorphization of the substrate is thus necessary to decrease boron diffusion by thermal budget reduction, the latter being obtained by the use of the thermal conduction tool (Levitor) instead of the classical lamp-type rapid thermal annealing. At the same time we show that the use of Levitor does not enhance boron activation, the substrate being preamorphize or not. So Levitor anneal can improve sheet resistance/junction depth trade-off only with preamorphization implant. Experiments are performed that confirm the predictions of our simulations. Further discussions explain activation path of boron during temperature cycle, as a function of amorphous depth, and for both lamp-type and Levitor anneal.
Concentration-Dependence of Self-Interstitial and Boron Diffusion in Silicon
Authors: Windl Wolfgang 
Published: April 2011

ABSTRACTIn this paper, we discuss the accuracy of ab-initio calculations for self-interstitial and boron dif-fusion in silicon in light of recent experimental data by de Salvador et al. and Bracht et al. Map-ping the experimental data onto the activation energy vs. Fermi level representation commonly used to display ab-initio results, we show that the experimental results are consistent with each other. While the theoretical LDA value for the boron activation energy as a function of the Fermi level agrees well with experiment, we find for the self-interstitial in line with other calculations an underestimation of the experimental values, despite using total-energy corrections.
Effects of Oxygen on the Microstructures, Crystallization, Thermal and Electrical Properties of Tellurium Doped GeSb9 Films
Authors: Shih Hsiang-Wen , Perng Yu-Hsung , Chou Lih-Hsin 
Published: April 2011

ABSTRACTTellurium and oxygen co-doped GeSb9 films (denoted as GeSb9-Te/O) with fixed Te concentration for phase change random access memory (PRAM) are investigated. The crystallization temperatures increased from 169°C to 201°C and the crystallization activation energy decreased from 5.53 eV to 2.89 eV as the oxygen concentration increased from 0 at.% to 17.3 at.%. The structures of crystalline GeSb9-Te/O films annealed at 250°C are identified as Sb rhombohedral structure with oxygen concentration less than 18 at.%, and the lattice parameter increased from 4.48 Å to 4.52 Å as the oxygen concentration increased from 0 at.% to 17.3 at.%. The grain size became smaller after oxygen doping. For films with oxygen concentration below 6 at.% and annealed at 250°C, only some of Ge form germanium suboxide GeOx, others remain metallic state. In films with oxygen concentration 28.1 at.% and annealed at 250°C, the GeO2 bond and Sb2O3 bond co-existed. The resistivity of amorphous phase (or crystalline phase) increases from 5.17 Ω-cm to 24.81 Ω-cm (or 1.12×10−4 Ω-cm to 1.05×10−3 Ω-cm), about 4.8 times (or about 9.4 times) as oxygen concentration increases from 0 at.% to 17.3 at.%. The film properties show beneficial in PRAM application.
Characterization of Thermally Evaporated Ag-Ge-S Thin Films
Authors: Wang Fei , Dunn William Porter , Jain Mukul , De Leo Carter , Vicker Nicholas , Savage Richard , Jin Xiaomin , Mamedov Sergey , Boolchand Punit 
Published: April 2011

ABSTRACTThin films of ternary (GeS3)1−xAgx glasses (x=0.1 and 0.2) are studied in this work. Thin films are fabricated in a vacuum thermal evaporator at 3 different evaporation angles (0°, 30° and 45°). All thin film samples are examined in Raman spectroscopy. Raman results of both normally and obliquely deposited thin film samples reveal Ge-S CS modes (∼340cm−1) , Ge-S ES (∼360cm−1) modes, and thiogermanate modes Q1∼Q3 (390cm−1∼437cm−1). In addition, sharp peaks due to sulfur rings (S8) are observed at 218cm−1 and 470cm−1. Raman line-shapes of thin films are qualitatively consistent with their corresponding bulk glasses. However, the sharp peaks due to sulfur rings were not observed in bulk glasses. By comparing CS modes of thin films of three angles, we observe that normally deposited (0 degree) thin film shows a red-shift in center and a broadening in width. The film thickness of normally deposited films are significantly smaller comparing with that of corresponding obliquely deposited films.
Thermally-Stable High Effective Work Function TaCN and Ta2N Films for pMOS Metal Gate Applications
Authors: Adelmann Christoph , Lehnen P. , Ragnarsson L.-Å. , Conard T. , Franquet A. , Chang V. S. , Rohr E. , Meersschaut J. , Boissière O. , Lohe C. , Schram T. , Van Elshocht S. , De Gendt S. 
Published: April 2011

ABSTRACTTaCN-based metal films were grown by metal-organic chemical-vapor deposition (MOCVD) and atomic vapor-deposition (AVD). Thermal decomposition at 500ºC leads to com-positions of approximately Ta0.50C0.4N0.1 (“TaCN”), whereas a reactive process using NH3 leads to the formation of Ta0.65C0.1N0.25 (“Ta2N”) films. All films are nearly amorphous as grown and recrystallize only weakly after spike annealing at 1050°C. The thermal stability of TaCN/HfSiO4 and Ta2N/HfSiO4 stacks during spike annealing at 1050°C was studied and Si and Hf outdiffusion into TaCN or Ta2N was observed. The effective work functions of TaCN and Ta2N on HfSiO4 were found to be as high as 4.9 eV after high thermal budget. It is demonstrated that the effective work function can be further increased to 5.1 eV after high thermal budget by the insertion of a thin Al2O3 capping layer between HfSiO4 and the metal films.
Electrical Properties of Thermally Grown HfO2 and HfO2/TiO2/HfO2 MIM Capacitors fabricated on SiO2/Si Substrate and HfO2 MIM Capacitors Fabricated on Sapphire
Authors: Miao Bing , Mahapatra Rajat , Wright Nick , Horsfall Alton 
Published: April 2011

ABSTRACTThe scaling of contemporary metal-insulator-metal (MIM) capacitors requires oxides of higher dielectric constant (>10), such as hafnium oxide (∼18) and titanium oxide (∼40). Intensive research of these oxides and oxide stacks is needed to develop them into high quality electronic materials for their application as capacitors in high temperature environments. High-k dielectrics such as HfO2 and HfO2/TiO2/HfO2 have been grown by thermal oxidation to fabricate MIM capacitors on SiO2/Si substrates and on sapphire substrates also. The thermally grown Al/HfO2/TiO2/HfO2/Pt/Ti/SiO2/Si MIM capacitor is reported here for the first time. The MIM capacitor using HfO2/TiO2/HfO2 dielectric film shows a similar frequency dependence using HfO2 dielectric on a SiO2/Si substrate, whilst its voltage linearity coefficients, leakage current and temperature coefficient are higher than the capacitor employing HfO2 dielectric. The MIM capacitor with HfO2 dielectric fabricated on sapphire substrate shows the strongest frequency dependence, voltage linearity coefficient and temperature dependence which is related to the surface roughness of substrate. The high capacitance density of these capacitors, ranging from 5.21 fF/µm2, meets the ITRS requirements for analog capacitor up to 2012. The MIM capacitor using 30nm HfO2 dielectric film illustrates highest capacitance density, 5.21 fF/µm2, a VCC of 236 ppm/V2, a temperature coefficient of 290 ppm/ºC, measured up to 300 ºC, and leakage current density which is 1.3 × 10−7 A/cm2 at 1V.
Study of Coercivity-enhanced Ruthenium-doped La0.67Sr0.33MnO3 Thin Films for Pseudo Spin Valve Devices
Authors: Chan Yuk Kwan , Cheng Wang Fai , Lau Hon Kit , Leung Chi Wah 
Published: April 2011

ABSTRACTThis investigation focused on the study of La0.67Sr0.33MnO3 (LSMO) thin films with 5 atomic percent Ru-doping (LSMRO). Specifically, we fabricated epitaxial LSMO and LSMRO thin films on LaAlO3 (LAO) (001) substrates by pulsed laser deposition. Resistance- temperature measurement results showed that the Curie temperature (Tc) of LSMRO thin film deposited under an oxygen ambient pressure of 150 mTorr at 830 °C was above room temperature. Hysteresis measurements and anisotropic magnetoresistance (AMR) results confirmed that coercivity of the optimized LSMRO films, as compared with that of LSMO films, can be greatly increased at low temperatures. The study successfully demonstrated the coercivity enhancement effect of Ru-doping on LSMO thin films deposited on LAO substrates.
Effect of the Surface Structure of Thin Layers on Their Reactivity
Authors: Dultsev Fedor 
Published: April 2011

ABSTRACTChanges of the electron properties of surface atoms of silicon dioxide film caused by the adsorption of donor-type gas-phase molecules (H2O, O2, NH3, HF) were modeled with the help of semiempirical methods and molecular mechanics. It was shown that the adsorption capacity and reactivity of the layers depend on the Si-O-Si bond angle. The results of calculations are in good agreement with the experimental data and confirm our hypothesis concerning the rearrangement of the surface layer stimulated by the adsorbed molecule.
CuxO/CeO2 Nanocomposites: Synthesis and Reactivity with NO
Authors: Scopel Federico , Galenda Alessandro , Natile Marta Maria , Glisenti Antonella 
Published: April 2011

ABSTRACTCuxO/CeO2 nanocomposite powders were prepared by wet impregnation of nanosized ceria powder (Cu/Ce nominal atomic ratio from 0.05 to 0.5). XP analysis reveals the presence of Cu2O in the samples with lower Cu/Ce atomic ratio whereas CuO is prevalent in the samples richer in copper. The surface Cu/Ce atomic ratio obtained from XPS data is always higher than the nominal one suggesting the surface segregation of copper. A plateau value (0.9-1.0) is reached for the samples with a nominal Cu/Ce atomic ratio of 0.2 suggesting an island growing mechanism.The nanocomposite samples and the supporting ceria were exposed to a NO+CO mixture (2% CO, 2% NO, 96% He) and the reactivity was investigated by means of DRIFT spectroscopy and QMS. At 523 K (i.e. the temperature at which the nanocatalysts activity is higher) the capability for NO reduction increases with increasing the Cu/Ce atomic ratio.
Bonding Structure of Ultrathin Oxides on Si(110) Surface
Authors: Yamamoto Yoshihisa , Togashi Hideaki , Kato Atsushi , Suemitsu Maki , Narita Yuzuru , Teraoka Yuden , Yoshigoe Akitaka 
Published: April 2011

ABSTRACTThe thermal oxidation kinetics of Si(110) surface up to oxide layer thickness of 1 ML has been investigated by real-time monitoring of chemical shifted in the Si 2p core-level photoemission using synchrotron radiation. The uptake profiles of every Si oxidation states (Sin+: n = 1 − 4) indicate that the top surface Si(110) oxidation proceeds through a two-step oxidation pathway via Si2+ state, just like the Si(001) surface. In contrast to the Si(001) oxidation, however, Si3+ state is always more abundant than Si4+ state during oxidation. This is related to occurrence of imperfect oxidation of this surface, most probably due to accumulation of compressive strain during oxidation.