bluuebunny/crossref_metadata_2025_split huggingface dataset:
Behavior Of The Potential N-Type Dopants P And As In Diamondafter Low Dose Ion Implantation
Authors: Hofsäss H. , Dalmer M. , Restle M. , Ronning C. , Bharuth-Ram K. , Quintel H. , Isolde-Collaboration The 
Published: April 2011

AbstractWe have studied the lattice sites of P and As impurities in natural IIa diamond after room temperature ion implantation at very low doses of 1011 P/cm2 and ≤ 1013 As/cm2 and subsequent annealing. We implanted radioactive 33P and 73Se/73As probe atoms and used the sensitive emission channeling technique to determine the impurity lattice sites. In this technique the channeling effects of emitted decay electrons are measured for different crystal axes. By comparison with calculated electron emission distributions the fractions of emitter atoms on different lattice sites can be quantitatively determined. After annealing of the implanted samples above 900°C we find high substitutional fractions of 70 ± 10 % for 33P and 55 ± 5 % for 73As.
Optical And Electrical Characterisation Study Of SICL4 Reactive Ion Etched Gaas
Authors: Murtagh M. , Ye Shu-Ren , Masterson H.J. , Beechinor J.T. , Crean G.M. , Auret F.D. , Deenapanray P.N.K. , Meyer W.E. , Goodman S.A. , Myburg G. 
Published: April 2011

AbstractIn this study 1016cm−3 n-type epitaxial GaAs was reactive-ion-etched (RIE) in a parallel plate type reactor as a function of rf power and gas pressure using a SiCl4 plasma. The sample matrix followed a 3 level 3 factorial statistical experimental design. Photoreflectance (PR) was employed to characterise the etch induced modification to the electronic band structure at the fundamental band-edge transition. Variable angle spectroscopic ellipsometry (VASE) and photoluminescence (PL) optical diagnostic techniques are also employed to characterise the plasma processed GaAs. PR results detail a decrease in the surface electric field (Fs) with etch severity arising from an RIE induced electron trap that increases in concentration with energetic ion sputtering. For the highest rf power densities PR further distinguishes between reactant desorption and adsorption limited etching regimes. VASE and PL data reveal the extent and degree of surface modification of the etched substrates. Atomic-Force-Microscopy showed the etched surfaces to have an average roughness, Ra of 15nm. Optical characterisation data are correlated with electrical measurements using fabricated Schottky barrier diodes for deep-level-transient spectroscopy (DLTS) as well as current-voltage and capacitance-voltage (CV) analysis. CV results detail a reduced surface carrier concentration after RIE while DLTS revealed the emergence of six electron trap defect levels. One of the two prominent RIE induced trap levels exhibited similar DLTS behaviour as that produced after ion bombardment of n-type (Si) GaAs.
Characterization of PECVD Deposited Fluorosilicate Glass (FSG) After CMP and Cleaning
Authors: Mordo D. , Goswami I. , Malik I. J. , Mallon T. , Emami R. , Withers B. 
Published: April 2011

AbstractA characterization of Plasma-Enhanced CVD Fluorinated Silicate Glass (FSG) is presented. This study investigates the behavior of FSG film in the Chemical Mechanical Polishing (CMP) environment and compares those characteristics to undoped TEOS (UTEOS), Thermal Oxide and Si-Rich oxide capped FSG films. The removal rate, refractive index (RI), surface roughness, contact angle, water content by FTIR and thermal desorption spectroscopy (TDS) were studied.The FSG films are polished ˜ 10% faster than the undoped PECVD oxide films. Their composition was slightly changed after CMP as can be seen by the minor increase in the RI. A layer of Si-Rich oxide (SRO) was found to have a stabilizing effect on the FSG film during CMP and post CMP cleaning operations, and thus can be used in the intermetal dielectric schemes that require low dielectric constant FSG layers.
Poly(Arylene Ethers) as Low Dielectric Constant Materials for ULSI Interconnect Applications
Authors: Vrtis Raymond N. , Heap Kelly A. , Burgoyne William F. , Robeson Lloyd M. 
Published: April 2011

AbstractPoly(arylene ethers)s are low dielectric constant organic spin on materials. PAE-2, which is a non-fluorinated poly(arylene ether), exhibits a dielectric constant below 3.0, thermal stability greater than 425 °C as well as excellent adhesion to Si, SiO2, and Al. These are the major atributes which makes it a very attractive candidate for integration as an interlevel or inter-metal dielectric material (ILD). Material properties including dielectric constant, thermal stability, moisture absorption, and mechanical analysis will be discussed.
Comparison of Three Low Dielectric Constant Organic Polymers
Authors: Case C. B. , Case C. J. , Kornblit A. , Mills M. E. , Castillo D. , Liu R. 
Published: April 2011

AbstractThree low dielectric constant organic polymers are being investigated for possible use in a conventional, subtractive etch, multi-level metal process with PVD Al plugs. Material properties, physical properties, planarization ability and etch chemistries are compared, as well as the possibility of using these materials in a low temperature PVD A1 plug process.
Preliminary Electrical Characterization of Pulsed-Plasma Enhanced Chemical Vapor Deposited Teflon-like Thin Films
Authors: Labelle Catherine B. , Limb Scott J. , Gleason Karen K. , Burns James A. 
Published: April 2011

AbstractPulsed-rf excitation of hexafluoropropylene oxide (HFPO) has been used to deposit films with chemical compositions similar to poly(tetrafluoroethylene) (PTFE). Films were deposited at pulse cycles of 10/20, 10/50, 10/200, and 10/400 ms on/ms off and analyzed using electron spin resonance spectroscopy (ESR). All four films produced similar broad ESR spectra, with an average width at maximum slope of ˜60 G and a g-value of 2.0045. The concentration of free electrons in a sample decreased with increasing pulse off time. This behavior can be modeled by the reaction of a free radical with a gas species, assuming that free radicals are generated only during the pulse on time. The films' dielectric constants were found to decrease from 1.99 to 1.95 for pulse off times increasing from 20 to 400 ms.
Influence of the Cure Process on the Properties of Hydrogen Silsesquioxane Spin-On-Glass
Authors: Többen D. , Weiganda P. , Shapiro M.J. , Cohen S.A. 
Published: April 2011

AbstractHydrogen silsesquioxane spin-on-glass (SOG) is regarded as a potential low-k material for multilevel metallization (MLM) schemes. In this work we report on the properties of films which have been cured at different temperatures covering the range from 350°C to 850°C. It is found that the material remains in its microporous structures at the lower temperature while it can be strongly densified at increased thermal budgets. The slope of the dielectric constant indicates that care ought to be taken in subsequent metallization anneals in order to preserve the low-k values observed.
Deposition and Characterization of Porous Silica Xerogel Films
Authors: Jin Changming , List Scott , Yamanaka Stacey , Lee Wei William , Taylor Kelly , Hsu Wei-Yung , Olsen Leif , Luttmer J.D. , Havemann Robert , Smith Douglas , Ramos Teresa , Maskara Alok 
Published: April 2011

AbstractThe continued scaling of device feature size demands the use of low permittivity intermetal dielectric materials. Porous silica xerogel films have low dielectric permittivity through the incorporation of micropores into the SiO2 network. A feasible xerogel process has been developed. Crack-free and uniform silica xerogel films up to two microns in thickness with targeted porosity were readily coated. Xerogel materials completely filled 0.3 μm wide gaps with a 2:1 aspect ratio. MOSCAP measurements revealed a low permittivity and high dielectric breakdown strength. The dielectric breakdown strength is expected to be higher than that of ambient air because the average pore size of in the xerogel film is much smaller than the mean free path of the ambient air. Surface treated xerogel films were found to be hydrophobic as indicated by the absence of adsorbed moisture peaks in FTIR spectra. Xerogel films maintained their porosity after deposition of dense capping layers and a subsequent process under 700 atm Ar pressure at 400 °C. Test structures containing xerogel were successfully planarization with CMP and went through a tungsten plug deposition process without delamination nor collapsing. These results reflect the reasonable mechanical strength of xerogel films.
Characterization of a‐SiNx Thin Film Deposited By Inductively Coupled Plasma Enhanced Chemical Vapor Deposition
Authors: Han Sang‐Soo , Jun Byung‐Hyuk , No Kwangsoo , Bae Byeong‐Soo 
Published: April 2011

AbstractSilicon nitride thin films are deposited at low temperature using the inductively coupled plasma enhanced chemical vapor deposition.(ICP‐CVD) N2 and SiH4 gases are used as reactant gases for deposition of silicon nitride thin films with low hydrogen content. Composition, refractive index, and hydrogen content of the films were examined with variation of N2 flow rate, RF power and substrate temperature. As N2 flow rate and RF power increase and substrate temperature is lowered, N/Si ratio is reduced producing higher refractive index of the film. Hydrogen content of the films is calculated by FTIR spectroscopy and is much less than those of the films deposited by conventional PECVD using SiH4/N2 gases since N2 gas is used instead of NH3 gas. Total hydrogen content is constant regardless of RF Power and N2 flow rate. However, the hydrogen content decreases with increasing substrate temperature due to the release of hydrogen at high temperature.
Direct Observation of Mobile Protons in SiO2 Thin Films: Potential Application in a Novel Memory Device
Authors: Vanheusden K. , Warren W.L. , Devine R. A. B. , Fleetwood D. M. , Schwank J. R. , Winokur P. S. , Lemnios Z. J. 
Published: April 2011

AbstractIn this work we show that annealing of silicon/silicon‐dioxide/silicon structures in forming gas (N2:H2; 95:5) above 500°C leads to spontaneous incorporation of mobile H+ ions in the buried SiO2 layer. We demonstrate that, unlike the alkali ions feared as killer contaminants in the early days, the space charge distribution of these mobile protons within the buried oxide layer can be very well controlled and easily rearranged with relatively high speed at room temperature. The hysteresis in the flat band voltage shift provides a unique vehicle to study proton kinetics in silicon dioxide thin films. It is further shown how this effect has great potential as the basis for a reliable nonvolatile FET memory device that is expected to be competitive with state‐of‐the‐art Si‐based memory technologies. The power of this novel device is its simplicity; it requires few processing steps, all of which are standard in Si integrated‐circuit fabrication.
Correlation of Electrical and Physical Properties of SIMOX BOX Affected by Various Implantation Parameters
Authors: Yoon J. U. , Kim G. N. , Krska J‐H Y. , Chung J. E. , Allen L. P. , Goodson K. , Kaeding O. , Nauka K. 
Published: April 2011

AbstractThe impact of two implant parameters, namely the implant substrate temperature and implant beam current, on the physical and electrical properties of SIMOX buried oxide are investigated. Three implant substrate temperatures, 540 °C, 590 °C, and 640 °C and three beam current, 45 mA, 55 mA, 65 mA, are investigated. Results from thermal conductivity and surface photovoltage measurements show no apparent differences between samples. Results from interface roughness shows a decreasing trend as the substrate temperature and beam current increases. For the samples with different implant temperatures, the high‐field conduction shows an opposite dependence for top‐interface versus substrate injection. This behavior can be explained by the conservation of silicon in the buried oxide. Correlation of surface photovoltage and high‐field conduction shows weak positive dependency while that of interface roughness and high‐field conduction shows dependency only when the sets of temperature variation and beam current variation are decoupled.
Soft X-ray Si 2p core-level spectra of H8Si8O12 physisorbed on Si(111)-H: additional experimental evidence regarding the binding energy shift of the HSi03 fragment
Authors: Zhang K. Z. , Banaszak Holl Mark M. , McFeely F. R. 
Published: April 2011

AbstractThe hydridospherosiloxane cluster H8Si8012 has been physisorbed onto Si(111)-H and soft X-ray Si 2p core-level photoemission spectra obtained. The results of these experiments provide strong support for previous binding energy assignments of HSi03 moieties at -3.6 eV.
Gate Electrode Effects On Dielectric Breakdown Of SiO2
Authors: Toriumi Akira , Mitani Yuichiro , Satake Hideki 
Published: April 2011

AbstractWe discuss the gate electrode effects on SiO2 degradation in MOS structures. The gate electrode material was poly‐silicon, but the impurity doping procedure was varied in terms of species and concentrations. First, the origin of the substrate hole current observed in n‐MOSFETs, by injecting electrons from the silicon substrate, is discussed in terms of oxide thickness and gate electrode doping species, because the dielectric breakdown is closely related to the total hole fluence in the oxide. The effects of the gate electrode on the oxide network structure and on the Si/SiO2 interface are also experimentally investigated. Finally, the experimental results obtained for Qbd of different gate electrode MOSFETs are shown, including the polarity dependence of Qbd. Furthermore, the percolation analysis to explain the polarity dependence is introduced, since the dielectric breakdown process is really stochastic.
Characterization of Plzt on Platinum Electrodes for High Density Fram Application
Authors: Choi YongSoo , Choe SooDoo , Kim SeungHyun , Kim ChangEun , Yang DooYoung 
Published: April 2011

AbstractA new sol‐gel route to obtain PLZT thin film was developed by combining the advantage of 2‐methoxyethanol as a solvent and acetylacetone as a chelating agent. The sol maintained the same stable state as that of fresh synthesized sol even after 60 days of aging. The PLZT films spin coated onto a Pt/Ti/SiO2 substrate with 15% Pb excess and 7.5% La added sol showed well developed rosette microstructure of uniform grain sizes(0.3 ‐ 0.5 μm) and gave well behaved ferroelectric properties with the values of Ps, Pr, and Ec of 40 μC/cm2, 15 μ C/cm2, and 20 kV/cm respectively at 5V after 650 °C and above annealing. The degradation in polarization of 2.5% La doped PLZT thin film was found to be less than 20% up to 1012 cycles
The Optical Properties of Channel Waveguides in Batio3 Thin Films
Authors: Block B. A. , Wessels B. W. , Gill D. M. , Conrad C. W. , Ho S. T. 
Published: April 2011

AbstractBaTiO3 epitaxial films have been prepared on (001) MgO substrates by metalorganic chemical vapor deposition. The as‐deposited 0.2 μm thick films had a surface roughness of 12 nm. Channel waveguides were fabricated from the films and the optical throughput measured. To differentiate the surface scattering loss from the internal scattering loss, waveguides were also prepared with a surface planarization step to reduce the surface roughness to 2.5 nm. The waveguide loss was greatly reduced for the planarized waveguides. The results indicate that surface and side wall roughness accounted for the majority of the waveguide loss. Grain boundary grooving lead to surface roughness and routes to overcome this problem are discussed.
Assembly of thin Film Dielectrics by Sequential Adsorption Reactions of Unilamellar Inorganic Colloids
Authors: Fang Mingming , Kim Chy Hyung , Sutorik Anthony C. , Kaschak David M. , Mallouk Thomas E. 
Published: April 2011

AbstractSeveral layered inorganic materials (e.g. KCa2Nb3O10, KTiNbO5, and CsPb2Nb3O10) were prepared and their alkali cations exchanged by in aqueous acid. A fraction of the interlayer protons of HCa2Nb3O10 and HTiNbO5 can be replaced by tetra-n-butylammonium (TBA+), by reaction with TBA+OH. Intercalation of a sufficient amount of TBA+ causes complete exfoliation, and single, nanometer-thick sheets of these materials are thus obtained. By sequential adsorption of these two-dimensional colloidal polyanions and polymeric cations, monolayer sheets of layered perovskites can be stacked on silicon surfaces to give thin films of any desired thickness. The layered materials, the exfoliated colloids, and the thin film multilayers on silicon were studied by X-ray diffraction, transmission electronic microscopy (TEM), ellipsometry, and atomic force microscopy (AFM). The dielectric properties of the related bulk materials were measured, and are also discussed.
Effect of Reactive Nitrogen Gas on the Electrical and Optical Properties of Rf-Sputtered Amorphous Carbon Films
Authors: Lee Kwang Bae , Lee Duck Jung , Shin Yong Woo 
Published: April 2011

AbstractWe have investigated the changes in the temperature dependence of the dc conductivity and the optical gap with nitrogen content in amorphous carbon nitride (a-C:N) films, in order to find the effect of nitrogen doping on the electrical and optical properties of amorphous carbon films. Specimens were deposited onto borosilicate glass substrates by the rf magnetron sputtering method using Ar and N2 as a sputtering gas and a reactive one, respectively. The values of the activation energy of the dc conductivity, Ea, of these films are 0.3∼0.8 eV and those of the optical gap, Eg, are 0.8∼ 1.4 eV. Both values decrease with increasing nitrogen content, which is due to the increase of the concentration or average size of sp islands segregated into the sp matrix by nitrogen doping. From the investigation of the behavior of both Ea and Eg in accordance with the nitrogen content, we discuss the three subsequent shifts of band edge and Fermi level, accompanied with the subsequent changes of microstructure in a-CN films by nitrogen doping.
Europium doped CaF2 as a materials system for blue‐violet light emitting structures on Silicon
Authors: Chatterjee T. , Michellon C. , McCann P. J. , Fang X. M. 
Published: April 2011

AbstractThe electrical and optical properties of MBE grown Europium doped CaF2 layers onp‐ type Silicon (100) substrates reveal the possibility of using this materials system to fabricate light emitters on silicon. Low temperature MBE growth of the Eu:CaF2 layers permits the incorporation of up to 7.48 atomic weight % Eu in the epilayer without causing significant degradation of the layer ciystallinity. Strong room temperature photoluminescence in the blue‐violet spectral range has been observed in these samples, without any luminescence quenching even when the Eu concentration in the CaF2 epilayer is as high as 7.48 atomic weight percent. The current versus voltage data reveal that high current densities can be sustained through the Eu:CaF2 epilayers without causing catastrophic failure of the dielectric layer. Visible DC electroluminescence (EL) is observed by injecting electrons into Eu2+ doped CaF2 layers. High current densities up to ~50A/cm2 have been sustained through these materials with a DC bias of ~30 volts.
Safe Precursor Gas for Broad Replacement of SiH4 in Plasma Processes Employed in Integrated Circuit Production
Authors: Loboda M.J. , Seifferly J.A. , Grove C.M. , Schneider R.F. 
Published: April 2011

AbstractSilane (S1H4), a pyrophoric gas, is the most widely used gas for the growth of dielectric films used in integrated circuit manufacturing. The industry has extensive experience in the handling of silane, but as process throughput continues to increase, so to do the concerns regarding safety and implementation issues involving this material. Trimethylsilane ((CH3)3SiH) is a non-pyrophoric organosilicon gas which can be used as a safe replacement for silane. Its material properties allow for standard packaging and quick integration into plasma deposition processes. The use of a non-pyrophoric gas will increase safety and process equipment uptime. By direct comparison to silane based processes, it is demonstrated that high quality films of silicon dioxide and silicon nitride can be deposited from trimethylsilane. In addition, hard, inert amorphous silicon carbide films can be deposited using the gas as a single precursor.
Gas Stream Analysis and PFC Recovery in A Semiconductor Process
Authors: Hoeymissen J.A.B. van , Daniels M. , Anderson N. , Fyen W. , Heyns M. 
Published: April 2011

AbstractThe performance of pressure swing adsorption (PSA) technology was assessed for recovering PFCs from the exhaust of a semiconductor plasma process. Several PSA process conditions were run to determine an optimized system. Under well defined conditions, the PSA technique was found to be effective at separating C2F6 from nitrogen, although the balance between recovery and product purity was evident. The exhaust of a plasma chamber was analysed by mass spectrometers and plasma etching conditions were varied to determine the effects on the PSA performance. A gas reactor column (GRC) was tested as pre‐treatment of the capturing system
Plasma Etching of Silicon Dioxide and Silicon Nitride with Non-Perfluorocompound Chemistries: Trifluoroacetic Anhydride and Iodofluorocarbons
Authors: Karecki Simon M. , Pruette Laura C. , Reif L. Rafael 
Published: April 2011

AbstractPresently, the semiconductor industry relies almost exclusively on perfluorocompounds (e.g., tetrafluoromethane, hexafluoroethane, nitrogen trifluoride. sulfur hexafluoride, and. more recently, octafluoropropane) for the etching of silicon dioxide and silicon nitride films in wafer patterning and PECVD (plasma enhanced chemical vapor deposition) chamber cleaning applications. The use of perfluorocompounds (PFCs) by the industry is considered problematic because of the high global warming potentials (GWPs) associated with these substances. Potential replacements for perfluorocompounds are presently being evaluated at MIT. In an initial stage of the study, intended to screen potential candidates on the basis of etch performance, a large number of compounds is being tested in a commercially available magnetically enhanced reactive ion etch tool. The potential alternatives discussed in this work are trifluoroacetic anhydride (TFAA) and three members of the iodofluorocarbon (IFC) family – iodotrifluoromethane, iodopentafluorocthane, and 2-iodoheptafluoropropane. This paper will present the results of etch rate comparisons between TFAA and octafluoropropane, a perfluorinated dielectric etchant. Designed experiment (DOE) methodology, combined with neural network software, was used to study a broad parameter space of reactor conditions. The effects of pressure, magnetic field, and gas flow rates were studied. Additionally, more limited tests were carried out with the three iodofluorocarbon gases. Etch rate data, as well as Auger electron spectroscopy data from substrates exposed to IFC plasmas will be presented. All gases were evaluated using both silicon dioxide as well as silicon nitride substrates. Results indicate that these compounds may be potentially viable in plasma etching applications.