bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrical Damage Due to Low Energy Plasma Processing of GaAs Structures
Authors: Zappe Hans P. , Kaufel Gudrun 
Published: June 2019

ABSTRACTThe effect of numerous plasma reative ion etch and physical milling processes on the electrical behavior of GaAs bulk substrates has been investigated by means of electric microwave absorption. It was seen that plasma treatments at quite low energies may significantly affect the electrical quality of the etched semiconductor. Predominantly physical plasma etchants (Ar) were seen to create significant damage at very low energies. Chemical processes (involving Cl or F), while somewhat less pernicious, also gave rise to electrical substrate damage, the effect greater for hydrogenic ambients. Whereas rapid thermal anneal treatments tend to worsen the electrical integrity, some substrates respond positively to long-time high temperature anneal steps.
Deposition Of Aluminium Nitride Film By Ion Beam Enhanced Reactive Magnetron Sputtering
Authors: Huang R. F. , Wen L. S. , Wang H. , Wu J. , Hong R. J. 
Published: June 2019

ABSTRACTAluminium nitride film has been synthesized at substrate temperatures lower than 100 °C by using ion beam enhanced reactive magnetron sputtering. The growth rate was much higher than that obtained by usual physical vapor deposition at low substrate temperatures. The stoichiometry of the film was controlled by varying the resultant current of the ion beam used and identified by X-ray diffraction analysis. The optical properties of the film were also studied.
PACVD Fluorinated Silicon Nitride Films Deposited From SiF4/NH3 GAS MIXTURES
Authors: Castro A. , Gasset M. , Gomez-Aleixandre C. , Sanchez O. , Albella J. M. 
Published: June 2019

ABSTRACTFluorinated silicon nitride films deposited from SiF4/NH3 gas mixtures by PACVD at two different frequencies have been investigated. At 13.56 MHz, low deposition rate was detected and no appreciable changes were observed when the deposition parameters varied in a wide range. On the contrary, higher deposition rates were achieved when a 35 KHz frequency was applied. These low frequency silicon nitride films showed an increase in the fluorine content In their structure when the SiF4 flow ratio in the gas mixture was increased, as detected by analytical resolution of the IR spectra. In addition, analysis of the plasma emission spectra has been performed in order to explain the effect of the plasma frequency in the deposition process.
Thin Film Growth Using Low-Energy Multi-Ion Beam Deposition System
Authors: Shimizu S. , Sasaki N. , Ogata S. , Tsukakoshi O. , Seki S. , Yamakawa H. 
Published: June 2019

ABSTRACTA high-current, low-energy multi-ion beam deposition system has been developed for the fabrication of tailored new materials. This system consists of two ion sources, a dual-sector type mass analyzer and a deceleration system. Several ion species can be extracted successively from the two ion sources by switching the mass analyzer selection. Artificially structured materials, especially having a layered structure, can be grown by the fine control of the growth process of each layer. Ar* ion deceleration characteristics of this ion beam deposition system and preliminary results about the epitaxial growth of Ca film on Si(100) are shown.
The Effects of Ion Energy on Carbon and Tungsten Films Fabricated by Direct Ion Beam Deposition and Ion Beam Sputtering Deposition
Authors: Kataoka I. , Ito K. , Hoshi N. , Yonemitsu T. , Etoh K. , Yamada I. , Delaunay Jean-Jacques 
Published: June 2019

ABSTRACTThe x-ray reflectivity and surface morphology of C/W multilayers fabricated by ion beam sputtering (IBS) method was evaluated. Also the surface roughness and amorphous structure of C and W films fabricated by direct ion beam deposition (DIBD) method were evaluated as a function of ion energy. The reflectivity was measured by the C-K line (4.47nm) and STM was used for surface roughness measurement and root-mean-square value of correlation function of the RHEED pattern was used for evaluation of amorphous structure. The reflectivity of C/W multilayer was about 69% of the theoretical one, and micro-columnar structures were observed from STM images. The film structure and surface roughness of DIBD film were changed with the depositing ion energy. The surface roughness of films becomes smaller as the depositing energy becomes higher in the energy range from 20 to 140eV.
Plasma Immersion Surface Modification With Metal Ion Plasma
Authors: I. G.  , Godechot X. , Yu K. M. 
Published: June 2019

ABSTRACTWe describe here a novel technique for surface modification in which a metal plasma is employed and by which various blends of plasma deposition and ion implantation can be obtained. The new technique is a variation of the plasma immersion technique described by Conrad and co-workers. When a substrate is immersed in a metal plasma, the plasma that condenses on the substrate remains there as a film, and when the substrate is then implanted, qualitatively different processes can follow, including ‘conventional’ high energy ion implantation, recoil implantation, ion beam mixing, ion beam assisted deposition, and metallic thin film and multilayer fabrication with or without species mixing. Multiple metal plasma guns can be used with different metal ion species, films can be bonded to the substrate through ion beam mixing at the interface, and multilayer structures can be tailored with graded or abrupt interfaces. We have fabricated several different kinds of modified surface layers in this way.
Selective Copper Plating in Silicon Dioxide Trenches with Metal Plasma Immersion Ion Implantation
Authors: Kiang Meng-Hsiung , Pico Carey A. , Lieberman Michael A. , Cheung Nathan W. , Qian X. Y. , Yu K. M. 
Published: June 2019

ABSTRACTSelective deposition of copper in SiO2 trenches has been carried out using plasma immersion ion implantation and electroless Cu plating. To form the seed layer for electroless Cu plating on SiO2 , sputtered Pd and Si atoms were partially ionized by the Ar plasma and then deposited at bottoms of SiO2 trenches; Ar ions also assisted the ion beam mixing of the deposited Pd/Si films with the SiO2 substrate. We found a threshold Pd dose of 2–3×1014/cm2 is required to initiate the electroless plating of Cu. By controlling the Pd dose and the tapering angle of the SiO2 trench sidewalls, 1 μm wide Cu filled lines with flat surfaces suitable for planarized multilevel metallization were successfully fabricated.
Argon Plasma Induced Surface Modifications For Resistless Patterning Of Aluminium Films
Authors: Agrawal Neeta , Tarey R. D. , Chopra K. L. 
Published: June 2019

ABSTRACTArgon plasma exposure has been used to induce surface chemical modification of aluminium thin films, causing a drastic change in etch rate in standard HNO3/CH3COOH/H3PO4 etchant. The inhibition period was found to increase with power and Ar plasma exposure time. Auger electron and x-ray photoelectron spectroscopies have indicated formation of an aluminium fluoride (AlF3) surface layer due to fluorine contamination originating from the residue left in the plasma chamber during CF4 processing. The high etch selectivity between unexposed and argon plasma exposed regions has been exploited as a new technique for resistless patterning of aluminium.
Simulations of Low-Energy Ion/Surface Interaction Effects During Epitaxial Film Growth.
Authors: Kitabatake Makoto , Greene J. E. 
Published: June 2019

ABSTRACTMolecular dynamics simulations were used to follow low-energy ion/surface interactions including kinetic energy redistribution in the lattice as a function of time, projectile and lattice atom trajectories, and the nature, number, and depth of residual defects. The simulations were carried out using the Tersoff many-body potential for Si. Irradiation events were initiated with 10 and 50 eV Si atoms incident normal to the Si(001)2×l surface at an array of points in the primitive surface unit cell. Ion-induced epitaxial growth was observed due to both Si projectiles and Si lattice atoms coming to rest at epitaxial positions through direct deposition as well as site exchange occurring via diffusional and collisional processes. 36 simulations of 10 eV (50 eV) Si bombardment resulted in an average stopping position of 0.5 Å (1.6 Å) below the surface, 10 (13) epitaxial events, 7 (24) exchange events between the projectile and a lattice atom, and the formation of 15 (63) interstitials and 0 (36) vacancies. The interstitials preferentially diffuse toward the surface and are annealed out over times corresponding to monolayer deposition at typical Si MBE growth temperatures.
Molecular Sieve Coated Saw Device for the Detection of Carbon Dioxide in the Presence of Water
Authors: Sun James T. , Dartt Christopher B. , Davis Mark E. 
Published: June 2019

Abstract158 MHz SAW oscillators coated with organic polymers and zeolites were tested as sensors for monitoring the level of humidity and carbon dioxide in a flowing stream of nitrogen. All coatings exhibited responses to water vapor on the order of kilohertz frequency shifts, while the responses to carbon dioxide were significantly (generally one order of magnitude) smaller. The presence of CO2 dramatically interfered with the detection of water with poly-(ethylenimine) (PEI) coatings. Poly-vinyl pyridine (PVP) coatings showed large responses to water without any interference from CO2; CO2 produced little response whether water was present or not. ZSM-5 coatings also showed no evidence of interference between water and CO2; a detectable response for CO2 is possible in humid nitrogen.
Stm Studies of GMR Spin Valves
Authors: Misra R. D. K. , Ha T. , Kadmon Y. , Powell C. J. , Stiles M. D. , McMichael R. D. , Egelhoff W. F. 
Published: June 2019

ABSTRACTWe have investigated the surface roughness and the grain size in giant magnetoresistance (GMR) spin valve multilayers of the general type: FeMn/Ni80Fe20Co/Cu/Co/Ni80Fe20 on glass and aluminum oxide substrates by scanning tunneling microscopy (STM). The two substrates give very similar results. These polycrystalline GMR multilayers have a tendency to exhibit larger grain size and increased roughness with increasing thickness of the metal layers. Samples deposited at a low substrate temperature (150 K) exhibit smaller grains and less roughness. Valleys between the dome-shaped individual grainsare the dominant form of roughness. This roughness contributes to the ferromagnetic, magnetostatic coupling in these films, an effect termed “orange peel” coupling by Néel. We have calculated the strength of this coupling, based on our STM images, and obtain values generally within about 20% of the experimental values. It appears likely that the ferromagnetic coupling generally attributed to so-called “pinholes” in the Cu when the Cu film thickness is too small is actually “orange peel” coupling caused by these valleys.
Hard Quasiamorphous Carbon - A Prospective Construction Material for Micro-Electro-Mechanical Systems
Authors: Dorfman Benjamin F. , Asoka-Kumar P. , Pollak Fred H. , Wan J. Z. , Zhu Qing 
Published: June 2019

AbstractA new form of sp3/sp2 carbon has been fabricated which exhibits a large number of valuable properties. This material combines low density (≤1.65 g/cm3), low stress (≤0,05 GPa), low thermal expansion (1.6×10−6 K−1) with high hardness (˜ 30 GPa), modulus (˜ 200 GPa), cracking threshold (≥ 3 N), fracture toughness (≥ 10 MPa-m1/2), long-term thermal stability (≥ 450°C in air and ≥ 600°C without oxygen), extremely high thermal shock resistance, excellent interface and adhesion to silicon, metals, and ceramics and an absolute resistance to the silicon etching acids. Most of its properties are actually constant up to 700K. The material combines a basically amorphous structure with one-axis anisotropy and a graphite-like layered arrangement with a length scale of the modulation about 14Å. We refer to this quasi-amorphous material as QUASAM. This paper describes QUASAM synthesis conditions, growth front planarity and material characterization with high-resolution x-ray diffraction, positron annihilation spectroscopy, atomic force microscopy and micro-Raman spectroscopy. In addition the mechanical and thermal examination of QUASAM and QUASAM/Si will be presnted in terms of micro-electro-mechanical systems (MEMS) and the technology prospective requirements of MEMS.
Structural Characterization of P++ Si:B Layers for Bulk Micromachining
Authors: Wu K. C. , Shay P. A. , Borenstein J. T. , Fitzgerald E. A. 
Published: June 2019

AbstractA range of techniques were used to characterize p++ silicon layers created by boron diffusion into (001) silicon wafers. These films were characterized by TEM, EBIC/ SEM, triple-axis XRD, SIMS, and modified Schimmel etching. Boron profiles predicted by SUPREM-3 process simulation software were compared to SIMS data. The results revealed gradients in boron and lattice constant, as well as a graded three-dimensional dislocation array from lattice-mismatch stress. Boron precipitation, induced by lattice-mismatch stress and concentrations above the solubility limit, was found to occur preferentially on dislocations. Additionally, the presence of dislocations was shown to affect the boron diffusion profile as well as etch morphology.
Characterization of the Piezoelectric Response of Aluminum Nitride Grown by dc Magnetron Sputtering for Applications in Thin-Film Resonators
Authors: Naik Rajan S. , Lutsky Joseph J. , Reif Rafael , Sodini Charles G. 
Published: June 2019

AbstractAluminum nitride is a promising material for use in thin-film bulk acoustic wave resonators for applications in RF bandpass filters. This paper discusses the requirements needed for a dc magnetron sputtering system to grow piezoelectrically active films with x-ray diffraction rocking curves of 3.3° on silicon substrates, 5° on aluminum substrates and oxygen concentrations of l at.%. For applications in integrated resonators, a materials characterization is insufficient in predicting the subsequent device performance. A simple acoustic device structure which allows a quick measurement of the device performance is used to extract maximum effective coupling coefficients keff2 of 0.009% at 3.4GHz and 0.002% at 2.4GHz for two different films with rocking curves of 5.7° and 9.0° respectively. This parameter extraction technique may be used to make relative comparisons between films grown under different deposition conditions.
The Effect of Inorganic Thin Film Material Processing and Properties on Stress in Silicon Piezoresistive Pressure Sensors
Authors: Bitko G. , McNeil A. C. , Monk D. J. 
Published: June 2019

AbstractSilicon bulk micromachined piezoresistive pressure sensors are sensitive to stresses caused by the application of inorganic thin films typically used for passivation purposes, and the change in stress that is caused by temperature changes in the operating environment of the sensor. Stress behavior over temperature is characterized for both thermal oxides grown on silicon at thicknesses from 0.18 μm to 0.36 μm, and PECVD silicon nitride films at thicknesses from 0.40 μm to 0.80 μn. Electrical parametric behavior is characterized for typical piezoresistive pressure sensors with these thin films deposited and patterned in several proposed passivation schemes. A finite element analysis is performed to predict how device parameters vary as a function of thin film patterning and properties. Correlations are drawn between model predictions, independent thin film behavior, and device performance.
Polymers for Optical-Communications Device Fabrication-Optical Adhesives and Polyimide Waveguides-
Authors: Maruno T. 
Published: June 2019

AbstractTwo types of novel organic materials have been specifically developed for the fabrication of optical-communications systems devices. One is a UV-curable durable epoxy adhesive featuring refractive index controllability, low shrinkage during curing, and a low heat-expansion coefficient. These optically transparent adhesives are refractive index controllable between 1.45 and 1.59, and have been successfully applied to many optical devices that require return losses of more than 40 dB. The precision adhesives show an extremely low volume shrinkage of less than 2% during curing. The submicron positioning accuracy of these adhesives allows the fabrication of highperformance laser-diode modules and optical modulators. The other type of material is a fluorinated polyimide (F-PI) for optical waveguides; it features high optical transparency from visible to near-infrared and good heat resistance. Buried optical waveguides fabricated from F-PI operate in a single mode. They also exhibit a low loss of less than 0.3 dB/cm at the wavelength of 1.3 μm, and are heat and moisture resistant: the increase in optical loss is less than 5% after heating at 300°C for lh or after exposure to 85% relative humidity at 85°C for 24h.
Technology for Microassembling
Authors: Johansson S. 
Published: June 2019

AbstractThe various problem areas regarding assembling of microelements into complex microsystems are reviewed and the joining techniques are emphasised in particular. The dis,-ussion is focused on the fabrication of microrobotic systems and the various joining techniques are compared with respect to the potential of fulfilling the demands for such a process. Factor.; such as processing conditions, precision, stability, materials limitations, bond and device strength are included in the comparison. Different methods for handling and manipulating microelements are discussed and the experimental equipment used in our own investigations is presented.
Xrd and Xtem Investigation of Polycrystalline Silicon Carbide on Polycrystalline Silicon
Authors: Roy S. , Zorman C. A. , Wu C. H. , Fleischman A. J. , Mehregany M. 
Published: June 2019

AbstractAtmospheric pressure chemical vapor deposition (APCVD) was used to grow silicon carbide (SiC) on as-deposited and annealed polycrystalline silicon (polysilicon) films which were deposited on oxidized Si wafers. X-ray diffraction (XRD) reveals that SiC films grown on asdeposited polysilicon have a (110) orientation. XRD performed on as-deposited polysilicon before and after SiC growth reveals that the orientation of polysilicon changes from (110) to a mixture of (110) and (11) during growth of 2 μm-thick SiC films. Cross-sectional transmission electron microscopy (XTEM) images of the SiC/polysilicon interface show that the SiC appears to be unaffected by the recrystallization of the underlying polysilicon during the SiC growth. XRD from samples of SiC grown on annealed polysilicon show that both films have (110) and (111) orientations. For SiC films grown on annealed polysilicon substrates, XTEM images show that the crystallinity of the annealed polysilicon substrate does not significantly change during SiC growth. Furthermore, an investigation of the SiC/annealed-polysilicon interface using selected area diffraction (SAD) shows that an epitaxial relationship exists between the polysilicon and SiC grains.
Improved Autoadhesion Measurement Method for Micromachined Polysilicon Beams
Authors: Boer Maarten P. de , Michalske Terry A. 
Published: June 2019

AbstractWe have measured autoadhesion (e.g. stiction) of individual polysilicon beams by interferometric optical microscopy. Untreated cantilever beams were dried from water in air, while treated beams were coated with a hydrophobic molecular coating of octadecyltrichlorosilane (ODTS). Adhesion values obtained for beams adhered to the substrate over a long length (large d) are independent of beam length with values of 16.7 and 4.4 mJ/m2 for untreated and treated samples respectively. These values can be understood in terms of differences in surface chemistry and polysilicon roughness. Using the shortest length beam which remains attached to the substrate, adhesion values were 280 and 16 mJ/m2 respectively. These higher values may be a result of capillarity effects. We recommend that measurements be made on beams in which d is large, in contrast to the current practice of noting the shortest beam adhered.
Optical Losses in Amorphous Silicon Solar Cells due to Back Reflectors
Authors: Sopori B. L. , Madjdpour J. , Von Roedern B. , Chen W. , Hegedus S. S. 
Published: June 2019

ABSTRACTWe have used a new numerical model and here present initial results on how texturing and backreflectors affect the maximum achievable short-circuit current densities in amorphous silicon solar cells.
Dependence of Reliability of Ultrathin Mos Gate Oxides on the Fermi Level Positions at Gate and Substrate
Authors: Yang Tien-Chun , Bhat Navakanta , Saraswat Krishna C. 
Published: June 2019

ABSTRACTWe demonstrate that the reliability of ultrathin (< 10 nm) gate oxide in MOS devices depends on the Fermi level position at the gate, and not on the position at the substrate for constant current gate injection (Vg-). The oxide breakdown strength (Qbd) is less for p+ poly-Si gate than for n+ poly-Si gate, but, it is independent of the substrate doping type. The degradation of oxides is closely related to the electric field across the gate oxide, which is influenced by the cathode Fermi level. P+ poly-Si gate has higher barrier height for tunneled electrons, therefore, the cathode electric field must be higher to give the same injection current density. A higher electric field gives more high energy electrons at the anode, and therefore the damage is more at the substrate interface. Different substrate types cause no effect on the oxide electric field, and as a result, they do not influence the degradation.
Effect of Cl in Gate Oxidation
Authors: Mertens P. W. , McGeary M. J. , Schaekers M. , Sprey H. , Vermeire B. , Depast M. , Meuris M. , Heyns M. M. 
Published: June 2019

ABSTRACTThe present study reviews the use of Cl in gate oxidation furnaces for growth of high quality gate oxides with a thickness in the range of 2 to 15 nm. The following, commercially available, “state of the art” Cl-precursors have been tested: 1,1,1- trichloroethane (TCA), irons-1,2-dichloroethylene (DCE) and oxalyl chloride (OC). Different parameters were evaluated including: metal removal efficiency, poly-silicon haze, Fe bulk incorporation, carrier lifetime and Cl-incorporation in the oxide. Cl2was identified as the active component in Cl-oxidation. As a consequence, OC was identified as being the most efficient Cl-source. In particular, OC is the most suited Cl-source for applications requiring reduced oxygen concentration, such as the manufacturing of ultra thin gate oxides.
The Effect of Roughness Features on Mos Surface Electric Field and Fowler-Nordheim Tunneling Behavior
Authors: Lin Heng-Chih , Kan Edwin C. , Yamanaka Toshiaki , Fang Simon J. , Eason Kwame N. , Helms C. R. 
Published: June 2019

ABSTRACTFor future CMOS GSI technology, Si/SiO2 interface micro-roughness becomes a non-negligible problem. Interface roughness causes fluctuations of the surface normal electric field, which, in turn, change the gate oxide Fowler-Nordheim tunneling behavior. In this research, we used a simple two-spheres model and a three-dimensional Laplace solver to simulate the electric field and the tunneling current in the oxide region. Our results show that both quantities are strong functions of roughness spatial wavelength, associated amplitude, and oxide thickness. We found that RMS roughness itself cannot fully characterize surface roughness and that roughness has a larger effect for thicker oxide in terms of surface electric field and tunneling behavior.
Identification of the Microscopic Structure of New Hot Carrier Damage Centers in Short Channel Mosfets
Authors: Billman C. A. , Lenahan P. M. , Weber W. 
Published: June 2019

ABSTRACTWe show, for the first time, that E'like centers can be generated in hot hole stressing of short channel metal oxide silicon field effect transistors (MOSFETs). Prior to this study only Pb centers had been directly linked to this stressing phenomenon.