bluuebunny/crossref_metadata_2025_split huggingface dataset:
Various Methods to Reduce Defect States in Tantalum Oxide Capacitors for DRAM Applications
Authors: Lau W.S. , Zhang G. , Leong L.L. , Qian P.W. , Han Taejoon , Das J. , Sandler Nathan P. , Chu P.K. 
Published: June 2019

AbstractTantalum oxide has attracted world-wide interest for DRAM (dynamic random access memory) capacitor applications because of its relative high dielectric constant compared to silicon dioxide or nitride. We would like to point out that tantalum oxide behaves very much like a large bandgap n-type semiconductor with 3 main types of donors responsible for leakage current. Native oxygen vacancies are very deep double donors with Ec – Ed = 0.8 eV approximately, where Ec is the bottom of the conduction band and Ed is the energy leVel of the defect state. Si-O vacancy complexes are relatively shallow single donors with Ec – Ed = 0.2-0.4 eV. C-O vacancy complexes are relatively shallow single donors with Ec – Ed = 0.5-0.6 eV. The key points regarding how to suppress these 3 types of donor defects will be discussed for the purpose of leakage current reduction.
Analysis of Nanoscale Deformation in GaAs(100): Towards Patterned Growth of Quantum Dots
Authors: Taylor Curtis R. , Stach Eric A. , Malshe Ajay P. , Salamo Gregory 
Published: June 2019

AbstractNanoindentations were created in the GaAs(100) surface to act as strain centers for the controlled nucleation and patterning of InAs quantum dots. A systematic approach is taken to understand the indent deformation processes that may lead to precision patterning capabilities for a broad range of nanostructures. Indents were generated using loads below 450 μN with a sharp cube corner indenter. Site-specific cross-sectional thinning of nanoindents (down to 100 nm in size) has been achieved using the in-situ ‘lift-out’ technique. This allowed for observation of subsurface deformation by transmission electron microscopy (TEM). The crystal was observed to deform solely by dislocation activity with no evidence of amorphization, twinning, fracture, or phase transformation. It is shown that the single phase deformation of GaAs can be well characterized and controlled, which should allow for exploitation of the dislocation strain field to bias nucleation of self-assembled quantum dots.
Silicon Wafer Defect Self-Characterization with CCD Image Sensors
Authors: McColgin William C. , Perryy Alexa M. , Seidler Dean J. , Lavine James P. 
Published: June 2019

AbstractToday's CCD image sensors can provide very high image quality. However, used as a tool, they can also provide a sensitive window into defects in silicon, either intrinsic to the starting wafers or introduced during fabrication. In this paper, we examine some cases of known silicon defects and show how they can appear in, and be studied by, CCD imagers. As examples, we discuss epi-layer defects, slip defects, and dark-current rings.
A Comparison of Lattice-Matched GaInNAs and Metamorphic InGaAs Photodetector Devices
Authors: Jackrel David B. , Yuen Homan B. , Bank Seth R. , Wisteyy Mark A. , Yu Xiaojun , Fu Junxian , Rao Zhilong , Harris James S. 
Published: June 2019

AbstractThe dilute-nitride GaInNAs shows great promise in becoming the next choice for 1 eV photodetector and multi-junction photovoltaic applications due to the ability for it to be grown lattice-matched on GaAs substrates. This paper will present results from high-power photodetector devices fabricated from high-quality thick GaInNAs and metamorphic InGaAs materials grown by MBE. The internal quantum efficiency of rear-illuminated PIN photodiodes with thick GaInNAs films as the intrinsic region (roughly 62% at 1064 nm) is somewhat lower than comparable metamorphic InGaAs devices (roughly 75% at 1064 nm). However, the dark current density of the GaInNAs devices is also somewhat lower (roughly 3 μA/cm2 at 2×104 V/cm bias) than the InGaAs devices (roughly 20 μA/cm2 at 2×104 V/cm bias), while the breakdown voltages (beyond -20 V) are comparable. Materials characterization of each structure, including x-ray diffraction and room-temperature as well as temperature-dependent photoluminescence studies will be presented in order to explain the characteristics observed in the devices composed of the two different material systems.
Mutual Passivation in Dilute GaNxAs1-x Alloys
Authors: Yu K. M. , Walukiewicz W. , Wu J. , Mars D. E. , Scarpulla M. A. , Dubon O. D. , Ridgway M. C. , Geisz J. F. 
Published: June 2019

AbstractThe dilute GaNxAs1-x alloys (with x up to 0.05) have exhibited many unusual properties as compared to the conventional binary and ternary semiconductor alloys. We report on a new effect in the GaNxAs1-x alloy system in which electrically active substitutional group IV donors and isoelectronic N atoms passivate each other's activity. This mutual passivation occurs in dilute GaNxAs1-x doped with group IV donors through the formation of nearest neighbor IVGa- NAs pairs when the samples are annealed under conditions such that the diffusion length of the donors is greater than or equal to the average distance between donor and N atoms. The passivation of the shallow donors and the NAs atoms is manifested in a drastic reduction in the free electron concentration and, simultaneously, an increase in the fundamental bandgap. This mutual passivation effect is demonstrated in both Si and Ge doped GaNxAs1-x alloys. Analytical calculations of the passivation process based on Ga vacancy mediated diffusion show good agreement with the experimental results.
Effects of Silicon Nitride Passivation Layer on Mean Dark Current and Quantum Efficiency of CMOS Active Pixel Sensors
Authors: Benoit D. , Morin P. , Cohen M. , Bulkin P. , Regolini J. L. 
Published: June 2019

AbstractIn the present study, we have analyzed the influence of the silicon nitride (SiN) passivation layer properties on the mean dark current and the quantum efficiency of CMOS APS (Active Pixel Sensor) through electrical characterization of lot wafers processed with three different SiN passivation films. The SiN layers were characterized by Spectroscopic Ellipsometry (SE) and Fourier Transform Infra Red (FTIR) spectroscopy to get the optical indices and the hydrogen content of the films, respectively. Hydrogen desorption was also studied by Thermal Desorption Spectrometry (TDS) experiments.The different chemical bond concentrations enable to explain the device performance. It is shown that high [Si-H] and low [Si-N] bonds concentrations lead to high hydrogen desorption from the SiN films. Thus, the lowest dark current values have also been obtained with such silicon nitride passivation layers. Consequently, results are in agreement with the hydrogen passivation of defects being responsible of thermally generated carriers. Concerning the quantum efficiency (QE), it is highly influenced by the optical indices of the SiN passivation layer.Actually, the thickness and complex refractive index of the SiN layer affect the light reflection, while the light absorption, in the visible range, is controlled by the [Si-Si] bonds concentration. There are also competing requirements to minimize dark current and to maximize quantum efficiency. In fact, high [Si-H] and low [Si-N] bonds concentrations (for good passivation) are generally observed in silicon-rich SiN films, which also contain high amount of [Si-Si] bonds (inducing high absorption, thus low QE). Increasing simultaneously the [Si-H] and [N-H] bonds concentrations in the passivation layer can be a way to have high hydrogen desorption during passivation anneal just preserving a transparent layer.
Effect of Deuterium Diffusion on the Electrical Properties of AlGaN/GaN Heterostructures
Authors: Arroyo Jaime Mimila , Barbé Michel , Jomard François , Ballutaud Dominique , Chevallier Jacques , Poisson Marie-Antoinette , Delage Sylvain , Dua Christian , Cordier Yvon , Hugues Maxime , Semond Fabrice , Natali Franck , Lorenzini Philippe , Massies Jean 
Published: June 2019

AbstractWe have studied the influence of a deuterium diffusion on the electrical characteristics of the 2D gas present in AlGaN/GaN heterostructures. The deuterium diffusion is performed by exposing the structures to a rf remote deuterium plasma. We find that both the sheet carrier concentration and the electron mobility decrease and that these effects are partly reversible under thermal annealing. These results suggest that deuterium behave as acceptors in the 2D gas region. The negatively charged deuterium act as additional scattering centers for electrons.
High Resolution Site-Selective Studies of Erbium-Centers in GaN and GaN:Mg.
Authors: Glukhanyuk V. , Przybylińska H. , Kozanecki A. , Jantsch W. 
Published: June 2019

AbstractIn this work the high resolution optical spectroscopy is used in order to determine the positions of the Stark split 4I15/2, 4I11/2 and 4I9/2 energy levels of Er3+ in GaN and GaN:Mg. Photoluminescence and photoluminescence excitation spectra were measured at energies corresponding to the 4I15/2→4I9/2 and 4I15/2→4I11/2 absorption transitions. Low Er implant doses were applied to reduce the number of possible defects. In undoped GaN only a single Er-center was observed and no influence of Mg doping on the energy level splittings of this center in GaN:Mg was found. Numerical analysis based on point charge model was used to calculate parameters of the local crystal field (CF) acting on Er3+ ions. The splittings of the 4I9/2 and 4I11/2 energy levels were calculated in weak CF approach and good agreement with experimental results was obtained. The calculations confirmed that the symmetry of the erbium center in hexagonal GaN is C3v.
Luminescence and Lifetime Properties of Europium Doped Gallium Nitride Compatible with CMOS Technology
Authors: Poitras Carl B. , Lipson Michal , Wu Huaqiang , Spencer Michael G. 
Published: June 2019

AbstractContinuous-wave and time resolved photoluminescence measurements on europium doped gallium nitride in the form of a powder are presented. The powder is obtained from reacting NH3 and a melt of gallium and europium with bismuth as a wetting agent. Photoluminescence from continuous wave excitation above the GaN bandgap reveals that an optimal concentration of about 1 at.% of Eu gives the most intense emission at 621 nm. Above gap time resolved photoluminescence reveals that energy transfer between the host material (GaN) and the rare earth ions occurs at a faster rate than previously reported for MBE grown GaN:Eu. Applications of the powder are directed towards CMOS compatible light emitters that are spun on silicon. A high temperature anneal of the powder shows no change in the CW photoluminescence spectrum of the powder, confirming CMOS compatibility.
On 2.7 νm Emission from Er-doped Large Bandgap Hosts
Authors: Vrielinck H. , Izeddin I. , Ivanov V.Y. , Gregorkiewicz T. , Callens F. , Lee D. S. , Steckl A. J. , Khaidukov N. M. 
Published: June 2019

AbstractThe potential of Er-doped Cs2NaYF6 and GaN for mid-infrared emission at λ≈ 2.7 ν is investigated using time-resolved optical spectroscopy. This emission results from electronic transitions between the second (4I11/2) and first (4I13/2) excited states of the Er3+ ion. By recording the photoluminescence transients for the 4I11/2 → 4I15/2 and 4I13/2 → 4I15/2 transitions after pulsed excitation, we determine the lifetime of the 4I11/2 level and demonstrate that the 4I13/2 state is populated from this level. Our results indicate that both host lattices should enable 2.7 νm emission, which is temperature-stable but subject to concentration quenching.
Energy-Back-Transfer Process in Rare-Earth Doped AlGaN
Authors: Wakahara A. , Fujiwara T. , Okada H. , Yoshida A. , Ohshima T. , Itho H. 
Published: June 2019

AbstractTemperature dependence of time-resolved photoluminescence (PL) properties for rare-earth ions (REIs: Eu, Tb, and Er) implanted AlxGa1-xN (x=0∼1) is investigated. Thermal quenching for RE-related PL becomes small when increasing the Al contents. The PL decay time of REIs used in the present work becomes shorter when increasing the temperature and/or PL peak energy. The temperature dependence of PL intensity and the decay time are analysed by assuming phonon assisted energy-back-transfer model, in which the energy in REIs escape to trap levels. From the results, the improvement of PL properties can be well explained by the model, in which the activation energy for energy-back-transfer process is increased as increasing the Al contents.
Tm-Er Codoping Al2O3 Thin Films: Activation by Annealing
Authors: Xiao Zhisong , Serna R. , Afonso C. N. , Vickridge I. 
Published: June 2019

AbstractAmorphous aluminum oxide (Al2O3) thin films codoped with Tm3+ and Er3+ have been prepared by pulsed laser deposition. A broad emission band with a full-width half maximum (FWHM) up to 230 nm was observed in Tm-Er codoped film. The spectrum shows two peaks located at 1540 nm corresponding to Er3+ emission and 1640 nm due to Tm3+ emission. The luminescence intensity dependence on the annealing temperature was investigated. It is shown that the annealing temperature and energy transfer between Tm3+ and Er3+ ions play an important role in the definition of the luminescent response.
The Impact of Deposition Parameters on the Optical and Compositional Properties of Er Doped SRSO Thin Films Deposited by ECR-PECVD
Authors: Flynn Michael , Wojcik Jacek , Gujrathi Subhash , Irving Edward , Mascher Peter 
Published: June 2019

AbstractSilicon rich silicon oxide films were fabricated by electron cyclotron resonance plasma enhanced chemical vapor deposition (ECR-PECVD). The films were doped in situ using an organometallic precursor. Optical measurements show that the refractive indices of the films are determined by the silane to oxygen flow rate ratio used during the depositions. The erbium content as measured by elastic recoil detection (ERD) is also strongly dependent on the oxygen flow rate, with more erbium being incorporated in the more highly oxygenated films. The erbium content was also found to vary inversely with plasma power, which did not have a significant effect on the silicon to oxygen ratio. This allows the erbium and excess silicon levels of the films to be controlled independently.
Hafnium-related Photoluminescence in Single Crystal Silicon
Authors: Sachdeva R. , Istratov A. A. , Shan Wei , Deenapanray P. N. K. , Weber E.R. 
Published: June 2019

AbstractA new photoluminescence (PL) band in the energy range of 700 meV to 950 meV associated with hafnium implanted in silicon is reported. A shift in the position of photoluminescence peaks observed on the samples implanted with two different isotopes of Hf confirms the Hfrelated origin of the observed photoluminescence band. Activation of the Hf-optical centers requires a 1000°C anneal step. The intensity of the PL lines depends on the cooling conditions. The spectrum consists of five peaks in the rapidly quenched sample as opposed to twenty one in the slowly cooled sample. Temperature dependent PL measurements and hydrostatic pressure measurements were performed to identify their nature.
Lattice Location of Rare Earth Ions in Semiconductors: Interpretation and Limitations of Using g Values
Authors: Carey David 
Published: June 2019

AbstractThe g values of rare earth ions obtained from either paramagnetic resonance or Zeeman measurements are often used to interpret the location and/or environment surrounding rare earth ions. In the case of centres with cubic symmetry the g value can be used to distinguish between substitutional and interstitial sites. For centres with less than cubic symmetry the average g value, taken as 1/3 trace of the g tensor, is often used as an indication of the lattice location and/or a measure of the strength of the local crystal field. This approach is widely used but is based on the assumption that the non-cubic terms in the total crystal field potential are small compared with the cubic crystal field. In this paper we have explored this assumption by calculating the principal g values in axial crystal fields for the Er3+ ion. We examine the limits over which the average g value approach is valid. Comparison is made with published results.
Novel Use of Surfactants in Copper Chemical Mechanical Polishing (CMP)
Authors: Hong Youngki , Patri Udaya B. , Ramakrishnan Suresh , Babu S.V. 
Published: June 2019

AbstractIn this study, the interaction between several kinds of surfactants and copper surface was examined to control the dissolution of copper during CMP. Among those surfactants, sodium dodecylsulfate (SDS), one of the conventional anionic surfactants, showed effective interaction with copper and significantly suppressed the dissolution of the copper at acidic and neutral pH ranges in a model copper CMP slurry system consisting of 3 wt% fumed silica, 1 wt% glycine, and 5 wt% hydrogen peroxide in deionized water. The inhibition performance of copper dissolution by SDS is better than that of Benzotriazole (BTA), a conventional inhibiting agent of copper dissolution in a copper CMP slurry.
Effect of Corrosion Inhibitor (BTA) in Citric Acid based Slurry on Cu CMP
Authors: Kim In-Kwon , Kang Young-Jae , Hong Yi-Koan , Park Jin-Goo 
Published: June 2019

AbstractIn this study, the effect of BTA on polishing behavior was investigated as functions of H2O2, slurry pH and abrasive particles. The addition of BTA effectively prevented Cu from etching by forming the passivation layer of Cu-BTA regardless of pH and H2O2 concentration in slurry. A thinner passivation layer was grown on Cu in BTA added slurry solutions with a higher contact angle of 60°. The dynamic etch rate, the removal rate with abrasive free slurry, also decreased when BTA was added in slurry at pH 2, 4 and 6. The removal rate of Cu was strongly dependent on types of abrasive particles in slurry. The larger hardness of slurry abrasive particles, the higher removal rates of Cu. The reduction of removal rates in BTA added slurry was determined by the competition between chemical dissolution rate and mechanical abrasion rate.
AFM Measurements of Adhesion between Actual CMP Slurry Particles and Various Substrates
Authors: Liu Yong , Zdyrko Bogdan , Tregub Alex , Moinpour Mansour , Buehler Mark , Luzinov Igor 
Published: June 2019

AbstractOne of the critical parameters in chemical mechanical polishing (CMP) technology is adhesion between abrasive particles and surfaces being polished. Accumulated up to date theoretical and experimental facts insist that development of advanced material removal and cleaning methods requires understanding and evaluation of particle adhesion in these processes. To this end, our research focuses on AFM studies of interaction between the slurry particles and different substrates treated by CMP processes. To conduct adhesion measurements, the particles present in a CMP system and model latex particle were first attached to the surface of silicon wafer covered with monolayer of polymer(s) having high affinity to particles and the silicon wafer. Glass/quartz sphere (10-60 microns) was attached to AFM cantilever with appropriate spring constant. (The sphere represented the surface of material being polished and might be covered with various materials during future investigations.) Next, AFM force volume mode, which utilizes the collection of the force-distance curves over selected surface areas, was used for the adhesion measurements.
Stress Characterization of Post-CMP Copper Films Planarized Using Novel Low-Shear and Surface-Engineered Pads
Authors: Deopura Manish , Hwang Edward , Misra Sudhanshu , Roy Pradip K. 
Published: June 2019

AbstractA family of novel low-shear and surface-engineered pads for copper chemical mechanical planarization (CMP) are designed and evaluated for polishing characteristics and process induced stress. Tribological studies are carried out on blanket copper films using these low-shear/surface-engineered pads and comparison is made with state of the art commercial pads (IC1000 and JSR). Results indicate that low-shear surface-engineered pads exhibit vastly improved tribological performance. These pads exhibit a 40% lower coefficient of friction (COF) over a larger range of Sommerfeld numbers (So) compared to commercial pads. A simplified XRD line profiling technique has been utilized to characterize stress within post-CMP copper films. The (222) Bragg peak position obtained from the XRD spectra of films polished using low-shear surface-engineered pads indicates virtually no shift compared to the peak position for the unpolished copper films. This result establishes that almost no stress is incorporated during bulk Copper removal using the newly designed pads.
Integration of CMP Fixed Abrasive Polishing into the Manufacturing of Thick Film SOI Substrates
Authors: Kulawski Martin , Luoto Hannu , Henttinen Kimmo , Suni Tommi , Weimar Frauke , Mäkinen Jari 
Published: June 2019

AbstractThe specification for the total thickness variation (TTV) of the device layers on thick-film silicon on insulator (SOI) wafers tighten for future applications. Therefore, the bulk removal polishing process of current technology after grinding cannot meet the demands in terms of flatness. The currently required amount of material removal for polishing out the induced sub surface damage (SSD) of the grinding is very high. Additionally, slurry-based CMP processes show unsatisfactory grindline and topography removal. This in turn reflects negatively to processing times, throughput and overall flatness performance.Encouraging early results of FA pad use for silicon and SOI polishing have already been further developed [1]. Low SSD grinding has been introduced to silicon manufacturing [[1]]. In this work, an integrated manufacturing process sequence is presented. Starting from low SSD grinding of the bonded SOI wafer couple, an optimized FA CMP step is replacing the conventional bulk polishing with reduced removal. The SSD after FA CMP is investigated by oxide induced stacking fault (OISF) method [[2]] and results are used to adjust the final polishing step of the substrates. The overall process sequence is highly advantageous in terms of performance in TTV and provides a highly competitive and effective method for achieving best possible surface quality with minimized total silicon removal. This method is not only useful for SOI wafers but also in other areas of silicon processing.
CMP Compatibility of Partially Cured Benzocyclobutene (BCB) for a Via-First 3D IC Process
Authors: McMahon J. J. , Niklaus F. , Kumar R. J. , Yu J. , Lu J.Q. , Gutmann R. J. 
Published: June 2019

AbstractWafer-level three dimensional (3D) IC technology offers the promise of decreasing RC delays by reducing long interconnect lines in high performance ICs. This paper focuses on a viafirst 3D IC platform, which utilizes a back-end-of-line (BEOL) compatible damascene-patterned layer of copper and Benzocyclobutene (BCB). This damascene-patterned copper/BCB serves as a redistribution layer between two fully fabricated wafer sets of ICs and offers the potential of high bonding strength and low contact resistance for inter-wafer interconnects between the wafer pair. The process would thus combine the electrical advantages of 3D technology using Cu-to-Cu bonding with the mechanical advantages of 3D technology using BCB-to-BCB bonding.In this work, partially cured BCB has been evaluated for copper damascene patterning using commercially available CMP slurries as a key process step for a via-first 3D process flow. BCB is spin-cast on 200 mm wafers and cured at temperatures ranging from 190°C to 250°C, providing a wide range of crosslink percentage. These films are evaluated for CMP removal rate, surface damage (surface scratching and embedded abrasives), and planarity with commercially available copper CMP slurries. Under baseline process parameters, erosion, and roughness changes are presented for single-level damascene test patterns. After wafers are bonded under controlled temperature and pressure, the bonding interface is inspected optically using glass-to-silicon bonded wafers, and the bond strength is evaluated by a razor blade test.