bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Causes of Property Variations of Ibad-Titanium Nitride
Authors: Kant R. A. , Dillich S. A. , Sartwell B. D. , Sprague J. A. 
Published: March 2011

ABSTRACTThe influence of the growth conditions on the composition, microstructure, and mechanical properties of TiN formed with low energy Ar+ ion bombardment during reactive physical vapor deposition was studied. The ratios of the incident ion and atom fluxes at the growth surface were varied systematically and were found to have a strong influence on both the composition and the microstructure of the films. These changes correlated well with measured changes in mechanical and optical properties. The films were examined using Auger electron spectroscopy, transmission electron microscopy, and their mechanical properties were studied using hardness, friction, and wear testing.
Microstructural Studies of Iad and PVD Cr Coatings by Cross Section Transmission Electron Microscopy
Authors: Cheng C. C. , Erck R. A. , Fenske G. R. 
Published: March 2011

ABSTRACTCross section transmission electron microscopy was used to study the microstructure and interface structure of Cr films deposited by ion-assisted deposition as a function of the incident ion energy. High-energy ion bombardment (1 keV) was found to enhance the adhesion of the deposited film owing to the formation of an intermixed layer, whereas deposition with lowenergy ions (100 eV) was found to reduce or eliminate grain boundary porosity. A tailored Cr film with excellent adhesion and no grain boundary porosity was deposited by combining highand low-energy ion bombardment.
Passivation of GaAs Laser Mirrors by Ion-Beam Deposited Al2O3
Authors: Webb D. J. , Dietrich H. -P. , Gfeller F. , Moser A. , Vettiger P. 
Published: March 2011

ABSTRACTThe use of ion-beam sputtered Al2O3 to passivate the mirrors of semiconductor injection lasers is described. Dense films, which offer considerable protection against corrosion, can be deposited without damage to the crystal surface. The overall quality of the passivation is demonstrated by long-term stress testing of the lasers.
Ion Beam assisted Deposition of Titanium Nitride
Authors: Hubler G. K. , Vanvechten D. , Donovan E. P. , Kant R. A. 
Published: March 2011

ABSTRACTThe composition of titanium nitride films prepared by ion beam assisted deposition was studied as a function of the partial pressure of N2 gas in the deposition volume, and as a function of the impingement 'ratio of nitrogen ions (500 eV) to evaporated titanium atoms. The amount of nitrogen incorporated from the ambient gas was derived by subtraction of the fraction introduced by the ion beam. It is shown that the primary effects of ion bombardment are an increase in the sticking coefficient and a reduction in the number of active surface adsorption sites.
Influence of Phosphorus Dopant Concentration on Recrystallization of Buried Amorphous Layers in SI(100) Produced by Channeled Implants
Authors: Schreutelkamp R. J. , Janssen K. T. F. , Saris F. W. , Westendorp J. F. M. , Kaim R. E. 
Published: March 2011

ABSTRACTBuried amorphous layers are produced in Si(100) by implantation of 100 keV P+ and Si+ ions under channeling condition along the <100>-direction. Rutherford Backscattering Spectrometry in combination with channeling shows that a continuous buried amorphous. layer with a thickness of 1300 Å results under a crystalline toplayer with a thickness of 600 Å. After Solid Phase Epitaxy a highly concentrated defect layer remains for all implants at the depth where the two amorphous/crystalline interfaces of the buried amorphous layer meet. Planar channeling along (100)-direction shows that dislocation loops are present after SPE regrowth at the ‘interface’ of the two crystalline regions for all implants. The size of the dislocation loops becomes smaller in the presence of phosphorus. Moreover, channeling analysis shows that in case of Rapid Thermal Annealing treatment in addition to the SPE regrowth process the defect structures present after full recrystallization can be more easily dissolved in case of the phosphorus implants as compared to the silicon self implant
Influence of the Implanted Species on the Residual Damage After Hot Implants in Silicon
Authors: Calcagno L. , Spinella C. , Catania M. , Campisano S. U. , Foti G. , Ferla G. , Rimini E. 
Published: March 2011

ABSTRACTDamage formation during hot implants of 600 keV As or Ge ions into Si was investigated by changing the target temperature (>150 °C) and the ion fluence. The defect distributions, as obtained by channeling analysis, are characterized by a gaussian shape whose maximum coincide with the peak of the energy density deposition and with a width of 200 nm. The amount of damage is a factor of two higher for Ge than for As ion implants, and a similar result was found for the damage created by Ge implants into bare Si or Si doped with a near constant As concentration of 2×10 20/cm3. The transition to amorphous formation is quite sharp for As (around 120 °C) and quite broad for Ge implants. The different amount and kind of extended defects is probably due to an interaction of the mobile point defects, vacancies and interstitials, with As. The interaction probably increases the defects annihilation rate.
Influence of Ion-Implantation on Characteristics of Picosecond Photoconductive Switches
Authors: Knudsen John F. , Bowman Robert C. , Smith Duane D. , Moss Steven C. 
Published: March 2011

ABSTRACTIon-implantation induced amorphization has been used to modify the linearity of response of ultrafast photoconductive switches fabricated on SOS. The extent of amorphization was determined using various materials characterization techniques. TRIM-86 Monte Carlo calculations were used to model the defect densities produced by ion implantation. Linearity of response is critically dependent upon the nature of the semiconductor region under metallic contacts and the character of the response is opposite to that expected from reports in the literature.
Formation of Shallow Boron P+ Junctions Using Sb Amorphization
Authors: Ganin E. , Davari B. , Harame D. , Scilla G. , Sai-Halasz G. A. 
Published: March 2011

ABSTRACTShallow P+ junctions have been fabricated using reverse-type dopant preamorphization by Sb. The junctions ∼100 nm in depth have leakage current below 10 nA/cm2, sheetresistance less than 200 Ω/□ and ideality factor in the range 1.01–1.03. This type of amorphization scheme provides electrical activation of B at low temperature, which is very promising for low temperature processing applications. The importance of process optimization was demonstrated. The electrical results were correlated with residual defect structure observed by cross-sectional TEM.
Silicided Shallow Junction Formation Using Ion Implantation and Thermal Annealing
Authors: Rubin Leonard M. , Herbots N. , Hoffman D. , Ma D. 
Published: March 2011

ABSTRACTThe combination of arsenic and boron implantation with rapid thermal annealing (RTA) has been investigated to form shallow p-n junctions under a titanium silicide (TiSi2) metallization. The use of TiSi2 as a connection material can lead to the destruction of the junction if the kinetics of silicidation and doping are not well controlled. The purpose of this study is to better understand and control these kinetics, using far-from equilibrium processing such as ion implantation and RTA. The structures were characterized by Rutherford Backscattering Spectometry (RBS) for arsenic and silicide profiling, Secondary Ion Mass Spectometry (SIMS) for boron profiling, Scanning Electron Microscopy (SEM), and electrical sheet resistance measurements. Two procedures were investigated. Both involved the thermal reaction of Ti thin films, sputter-deposited with thicknesses ranging between 40 and 80 nm. In the first experiment, the as-deposited films were implanted with either 115 keV arsenic or 28 keV boron to form the junction, disperse the native oxide, and ion beam mix the Ti and Si. The films were then subjected to an RTA at 750°C for 15 to 60 seconds, which leads to TiSi2 formation in unimplanted films. Implantation was found to actually prevent TiSi2 formation. Ion transport calculations indicated that dopant pile-up at the interface might inhibit silicidation while higher energies and larger implant doses can more effectively ion beam mix Ti and Si. A more attractive solution consists of first forming TiSi2 from the as-deposited Ti by RTA, and then implanting to form the junction. This resulted in better control of the junction thickness. A sharp increase in the TiSi2 resistivity was found after implantation but the original value could be restored by a second RTA. This RTA also electrically activated the dopants and recrystallized the junction. The material properties of Ti/Si and TiSi2/Si under ion bombardment, RTA, doping, and conventional furnace annealing will be discussed.
Plasma-Activated Ion Beam Reactive Sputtering of NbN Thin Films
Authors: Lichtenwalner D. J. , Anderson Alfredo C. , Rudman D. A. 
Published: March 2011

ABSTRACTIn order to better study and control the processes occurring in a reactive sputtering situation, a unique deposition method has been used in which the Ar-ion-beam sputtering of an elemental Nb target is combined with an auxiliary Ar/N2 plasma at the substrate. The ion source allows independent control of the sputtering parameters (ion flux, energy). The magnetically enhanced triode plasma provides a source of ionized and excited nitrogen at the film surface, and allows independent control of the substrate plasma parameters. A conductancelimiting enclosure surrounds the substrate, resulting in a pressure differential of nearly an order of magnitude between the substrate and target regions. This enables us to separate the substrate and target reaction regimes at low nitrogen flows. NbN has been investigated because of its technological importance and the fact that it is representative of transition metal nitrides.With the substrate plasma off and N2 provided at the substrate, the cubic superconducting NbN (δ phase) is produced even at low N2 flows, when the target is in the unreacted, metallic state. Upon increasing the N2 flow, the nitrogen content of the films abruptly increases as the target reaction proceeds. The addition of the substrate plasma results in the nonsuperconducting hexagonal δ' phase, which to our knowledge has not previously been produced as a singlephase thin film. The electrical properties of the δ' phase are reported.
About Some Peculiarities in Defect Appearence in Elemental and III–V Compound Semiconducting Materials
Authors: Kalitzova Maria G. , Pashov N. K. , Vitali G. , Rossi M. 
Published: March 2011

ABSTRACTHigh Resolution Transmission Electron Microscopy (HRTEM) has been used to obtain direct Information on the structure of damage clusters and in-depth radiation damage distribution in ion-implanted Ge and GaAs with Te+ and Si+ respectively, at doses far below the amorphization threshold. The observed changes in damage contrast in Te+ implanted Ge emphasize the existence of well defined separation between vacancies and interstitials in the lattice damage clusters. For GaAs an integrated “grey zone” was found as a typical effect of Si+ implantation.
On Energy and Dose Effects During Ion-Assisted Epitaxial Growth of InAs on Si(100)
Authors: Choi C.-H. , Barnett S. A. 
Published: March 2011

ABSTRACTEpitaxial InAs films have been grown on Si(100) substrates using triode ion-assisted deposition (TRIAD). The ratio r of the impinging Ar ion flux J to the deposited InAs flux was varied from 2.5 to 8.5 for Ar ion energies E from 5 to 55 eV. The growth temperature T was 350°C while the growth rate R was fixed at 0.6 μm/h. Two types of experiments were carried out. First, in order to investigate ion damage effects, X-ray diffraction rocking curve full-widths at half-maximum (FWHM) were measured as a function of E and r. In these experiments, the first 50 nm of InAs was always grown under the same conditions, r = 5 and E = 25 eV, in order to eliminate possible complicating effects caused by ion irradiation during InAs nucleation on Si, followed by 550 nm of growth at different E and r values. FWHM values increased with increasing E and r from 2800 arcsec, a value limited by defects arising from the 11% mismatch between InAs and Si, to 8900 arcsec as a result of ion damage. The FWHM value was found to be dependent on the total number of atomic displacements due to ion irradiation, estimated using a modified Kinchin-Pease expression. In the second set of experiments, E during the first 50 nm of growth was varied while ion irradiation damage in the remaining 5500 nm was minimized. Increasing E from 15 to 40 eV resulted in a decrease in the FWHM from 5500 to 2600 arcsec, followed by a gradual increase when E was increased above 40 eV. Ion irradiation at the onset of film growth thus reduced the propagation of defects from the InAs/Si interface into the film.
Ion Implantation of Boron in Diamond
Authors: Sandhu G. S. , Swanson M. L. , Chu W. K. 
Published: March 2011

ABSTRACTIt has been a challenge to inject dopant atoms onto diamond lattice sites by ion implantation, because of the complications of ion damage and defect clustering during annealing. We re-investigated this topic by implanting boron ions into an insulating natural diamond ( type II-A ) which was predamaged by carbon ion implantation. Both of the implantations were performed at liquid nitrogen temperature. The amount of pre-damage was adjusted to produce enough vacancies and interstitials in diamond to promote boron substitutionality during subsequent annealing. Samples were characterized by optical absorption and electrical measurements. It was found that optical absorption of the implanted samples strongly depends on the post implant annealing sequence. The activation energies obtained from electrical measurements match very closely to those due to boron atoms in natural p-type diamonds. Photoconductivity measurements showed that the fraction of remaining electrically active radiation defects in the implanted and annealed samples depends on the relative fluences of boron and carbon.
B(1−x)Nx Alloy Films Prepared by Ion Beam Assisted Deposition
Authors: Carosella C. A. , Hubler G. K. , Van Vechten D. , Donovan E. P. 
Published: March 2011

ABSTRACTWe have produced alloy films of B(1−x)Nx (x:0 to 0.5) via ion beam assisted deposition (IBAD). Rutherford backscattering spectroscopy (RBS) measurements show that the stoichiometric films are achieved with a nitrogen to boron atom arrival rate of N/B = 2.55. The film N/B ratio for all measured compositions is fit with a model that predicts that the nitrogen sticking coefficient is 0.36. Measurements of B(1−x)Nx film thicknesses with a profilometer confirm the value of this sticking coefficient. The BN film is transparent and has an refractive index that varies between 1.90 and 1.77 in the range 400 nm to 3100 nm. The refractive index data can be fit with the Sellmeier equation. Films 500 run thick with N/B less than 0.6 appear metallic; the index decreases linearly with increasing nitrogen content. The films have two broad absorption peaks, centered at 750 cm−1 and 1370 cm−1 that correspond to BN vibrations. The characteristics of the bands suggest that the films are amorphous or a microcrystalline hexagonal phase. The Knoop microhardness of the films generally decrease with increasing N content. Stoichiometric films have a microhardness of Hk = 20 GPa, measured with a 25 gm load.
Growth Mechanism of Direct Writing of Silicon in AR+ Laser CVD
Authors: Nagahori Takeshi , Matsumoto Satoru 
Published: March 2011

ABSTRACTSilicon lines are directly written using argon ion laser CVD. The thickness profile of the line has a Gaussian-like shape. The thickness profile is calculated with the model based on Arrhenius behavior. A good agreement is obtained.The effective exposure time is used to analyze the direct writing process. Using it, the average growth rate is estimated to be about 100 times faster than that of conventional large area CVD with the activation energy of 2.4± 0.4eV.
Laser Photochemical Vapour Deposition of Epitaxial Ge Films on GaAs from GeH4 Using NH3 as a Sensitiser
Authors: Kiely C.J. , Jones C. , Tavitian V. , Eden J.G. 
Published: March 2011

ABSTRACTThe viability of ammonia as a sensitiser for the epitaxial growth of Ge on GaAs by laser photochemical vapour deposition (LPVD) has been investigated. Specifically NH3/GeH4/He (0.8/5/95 sccm, 5.5 Torr total pressure) mixtures have been irradiated by a 193nm ArF excimer laser in parallel geometry for substrate temperatures, Ts<400°C. As evidenced by a dramatic acceleration in Ge film growth rate, the NH3 efficiently couples the laser radiation to the GeH4 precursor molecule. The microstructures of LPVD Ge films grown with and without NH3 have been examined by TEM, and the epitaxial nature of both types of films has been verified, although some subtle differences are noted. Chemical analysis of the deposited films has been carried out using Auger spectroscopy, X-ray photoelectron spectroscopy and secondary ion mass spectroscopy. Our results show that there is little or no nitrogen incorporation into the Ge films grown in the presence of NH3, and that hydrogen contamination in our films is minimal. The beneficial effect of NH3 on the growth rate of LPVD Ge films is attributed to the photolytic production of hydrogen atoms which efficiently decompose GeH4 by hydrogen abstraction collisions.
UV Enhancement of Surface Catalytic Polymerization of Ethylene
Authors: Purohit Parul Vora , Rothschild Mordechai , Ehrlich Daniel J. 
Published: March 2011

ABSTRACTThe polymerization of ethylene on surfaces sequentially dosed with TiC14 and trimethylaluminum was studied by Fourier transform infrared spectroscopy. The polymer film was observed in situ as a function of time and under the influence of 254-nm cw radiation. The rate of polymerization and the saturation thickness of the polyethylene are strongly dependent on the order of dosing and the partial pressures of the reactants that form the catalyst. UV enhancement of polymerization was demonstrated to occur through two separate photochemical channels: gas-phase photolysis of the reactants and solid-phase chemical transformation of a noncatalytic thin film.
Laser Induced Wet-Chemical Etching of Mn-Zn Ferrite in H3PO4
Authors: Lu Yong Feng , Takai Mikio , Nagatomo Syohei , Namba Susumu 
Published: March 2011

ABSTRACTMaskless etching of single crystalline Mn-Zn ferrite in an H3PO4 aqueous solution by Ar+ laser irradiation has been investigated to obtain high etching rates and aspect-ratios of etched grooves. The etching processes have been found to be photochemical in a low laser power region and thermochemical in a high laser power region. High etching rates of up to 340 pm/s and an aspect-ratio of 50 for slab structures have been achieved. Periodic ripple structures have been observed under specific etching conditions due to the local surface melting.
Excimer Laser Thin Metallic Film Patterning on Polyvinyledene Difluoridea)
Authors: Gauthier Michel , Bourret Richard , Jen Cheng-Kuei , Adler Eric L 
Published: March 2011

ABSTRACTTactile sensors and ultrasonic transducers based on the piezoelectric properties of polyvinyledene difluoride, PVF2, usually take the form of thin 10 - 110 μm polymer films coated on one or both sides with a metallic film. Electrode patterns are usually fabricated by photolithography that requires a 90 °C baking process which may harm the piezoelectric properties of the PVF2 film. We have developed an alternate method, based on direct patterning with a XeCl laser, yielding complex patterns of lines as narrow as 20 μm which are better than those fabricated by photolithography. The metallic film is ablated on both sides of the polymer while maintaining the intrinsic properties of the PVF2. The ablation mechanism is investigated using transmission optical, scanning electron, and scanning acoustic microscope images. The performance of an ultrasonic transducer fabricated with this technique is described.
High Current Density Electron Beam Induced Desorption
Authors: Berger S.D. , Macaulay J.M. , Brown L.M. , Allen R.M. 
Published: March 2011

ABSTRACTHigh current density electron beam irradiation with a small probe can lead to the production of holes in a variety of inorganic materials. We review some of the experimental observations of the hole formation process and compare these to the predictions of a simple model.
Formation of a Ni3O4 Spinel Phase on the Surface of NiO During Electron Irradiation
Authors: Buckett Mary I. , Marks L. D. 
Published: March 2011

ABSTRACTStructural changes occurring at the surface of NiO during electron irradiation were examined in-situ with a variable voltage high resolution electron microscope. The interaction of the specimen with the electron beam was found to be highly dependent on the state of the surface prior to irradiation. It was observed that by varying the sample preparation conditions, the Ni on the surface of NiO could either be oxidized to Ni304 spinel phase or reduced to islands of metallic Ni. The formation of the Ni3O4 spinel phase is in agreement with previous surface science studies, where chemical shift information identified the presence of Ni3+ species at the surface. This has previously been interpreted as the formation of Ni203
RF Plasma CVD Using Hollow Cathode Discharge
Authors: Araki Shin , Kamaji Hideki , Norimoto Kazuo 
Published: March 2011

ABSTRACTWe have made a-Si photoreceptors at low pressure to prevent the formation of SimHn powders and by separating the growing surface from the high density plasma. A new plasma CVD method using a hollow-cathode discharge, where the discharge electrode is the cathode, is described. There is a hollow region in the discharge electrode. Hollow-cathode discharge enables a high density plasma to form at low pressure. The gas is decomposed in the hollow cathode preventing plasma damage to the film. This method allows us to achieve a high deposition rate (10 µm/h) and good quality films for photoreceptors.
Selective-Area Laser-Assisted Processing for Microelectronic Multi-Chip Interconnect Applications
Authors: Miracky Robert F. 
Published: March 2011

ABSTRACTLaser direct-write processes are attractive complements to traditional methods of fabricating microelectronic circuitry. This paper is a summary of our work in applying such processes to high-density inter-chip interconnection modules, such as those using copper conductors on polyimide dielectric layers. We begin by discussing the requirements which laser processes must satisfy in order to be useful in this application. An analytical model of laser heating is then described, which aids in understanding the thermal problem of absorption of visible-wavelength laser light by polyimide. Calculations using this model are consistent with experimental observations. Finally, we focus on one laser processing technique: laser chemical vapor deposition. We describe a new process for laser chemical vapor deposition of tungsten on polyimide, which enables the formation of low resistance contacts (≈ 0.1 Ω) between the deposited tungsten films and pre-patterned nickel-coated copper conductors. Lines approximately 30 /m wide and 34 µm thick were deposited at a scan rate of 93 µm/s. From four-point resistance measurements of different lengths of deposited films, the tungsten film resistivity is estimated to be two to three times the bulk value.