bluuebunny/crossref_metadata_2025_split huggingface dataset:
High-quality hydrogen-diluted a-SiNx:H films deposited by hot-wire chemical vapor deposition
Authors: Liu Fengzhen , Gedvilas Lynn , Keyes Brian , Sanchez Errol , Wang Shulin , Wang Qi 
Published: April 2011

ABSTRACTWe have studied the effect of H dilution on silicon nitride films deposited by the hot-wire chemical vapor deposition (HWCVD) technique using SiH4, NH3, and H2 gases. We found that H dilution significantly enhances the properties at silicon nitride films. The N content in the film increases by more than 2 times compared to the film without dilution, based on FTIR measurements. As a result, we can achieve high-quality a-SiNx:H films at low substrate temperature using a much lower gas ratio of NH3/SiH4(∼1) compared to a ratio of about 100 for conventional deposition by HWCVD. We also found that dilution decreases the H content in the films. More importantly, diluted SiNx films are conformal. Scanning electron microscopy measurements show a nearly 100% surface coverage over a sharp object. Electric breakdown measurement shows a well-insulated film with more then a few MV/cm for the breakdown field.
Optical and Electronic Characterization of a-SiGe:H Thin Films Prepared by a Novel Hollow Cathode Deposition Technique
Authors: Soukup R. J. , Ianno N. J. , Darveau Scott A. , Exstrom Christopher L. 
Published: April 2011

ABSTRACTUsing a novel hollow cathode plasma-jet reactive sputtering system in which an intense plasma, ignited in an Ar/H2 flow, is directed through silicon and germanium nozzles, a series of a-SiGe:H thin films have been prepared on silicon and glass substrates. These films have been optically characterized by infrared (IR) spectroscopy and spectroscopic ellipsometry (335-1000nm). Total hydrogen concentrations, as determined by FTIR, varied with deposition conditions and ranged from 2.5 × 1021 to 1.6 × 1022 atom cm−3 and correlated with secondary ion mass spectrometry (SIMS) elemental analyses to within 10%. Conductivity measurements in the dark and under simulated AM1 solar illumination have indicated that the films properties are very good. The light to dark conductivity ratio has consistently been greater than 1000 for films with band gaps down to 1.3 eV.
Large-Area Hydrogenated Amorphous and Microcrystalline Silicon Double-Junction Solar Cells
Authors: Yan Baojie , Yue Guozhen , Banerjee Arindam , Yang Jeffrey , Guha Subhendu 
Published: April 2011

ABSTRACTHydrogenated amorphous silicon (a-Si:H) and hydrogenated microcrystalline silicon ( c-Si:H) double-junction solar cells were deposited on a large-area substrate using a RF glow discharge technique at various rates. The thickness uniformity for both a-Si:H and c-Si:H is well within ± 10% and the reproducibility is very good. Preliminary results from the large-area a-Si:H/m c-Si:H double-junction structures show an initial aperture-area efficiency of 11.8% and 11.3%, respectively, for 45 cm2 and 461 cm2 size un-encapsulated solar cells. The 11.3% cell became 10.6% after encapsulation and stabilized at 9.5% after prolonged light soaking under 100 mW/cm2 of white light at 50°C. High rate deposition of the c-Si:H layer in the bottom cell was made using the high-pressure approach. An initial active-area (0.25 cm2) efficiency of 11.3% was achieved using an a-Si:H/m c-Si:H double-junction structure with 50 minutes of c-Si:H deposition time.
Dominant Effect of p/i Interface on Dark J-V Characteristics in p-i-n Nano-crystalline Si Solar Cells
Authors: Das U. , Bozsa A. , Madan A. 
Published: April 2011

ABSTRACTNanocrystalline silicon (nc-Si) based p-i-n solar cells were fabricated onto various substrates using modified pulsed PECVD technique. Dark J-V characteristics of nc-Si p-i-n solar cells were found to depend strongly on the substrates and are studied at different i-layer thickness and varying the p/i interface structures. In this work, we report an almost constant diode quality factor (n = 1.2 – 1.3) up to the thickness of 3.8 μm for the devices grown on “suitably textured” ZnO substrates. The rather insensitive variation of n with i-layer thickness suggests that the dark J-V characteristics are not dominated by bulk recombination for the devices grown on textured ZnO, which prevents grain collision in the i-layer. In contrast to that, a significant change of n (1.8 – 1.3) was found while changing the p/i interface using various duration of H2 plasma treatment of nc-p surface (ST). The p/i interface structure in nc-Si p-i-n device plays the crucial role either by changing the p/i interface defects or the film structure at p/i interface determines the quality of subsequently grown nc-i layer and hence the whole device performance.
Dopant diffusion in amorphous silicon
Authors: Duffy R. , Venezia V.C. , Heringa A. , Hopstaken M.J.P. , Maas G.C.J. , Dao T. , Tamminga Y. , Roozeboom F. 
Published: April 2011

ABSTRACTIn this work we investigate the diffusion of high-concentration ultrashallow boron, fluorine, phosphorus, and arsenic profiles in amorphous silicon. We demonstrate that boron diffuses at high concentrations in amorphous silicon during low-temperature thermal annealing. Isothermal and isochronal anneal sequences indicate that there is an initial transient enhancement of diffusion. We have observed this transient diffusion characteristic both in amorphous silicon preamorphized by germanium ion implantation and also in amorphous silicon preamorphized by silicon ion implantation. We also show that the boron diffusivity in the amorphous region is similar with and without fluorine, and that the lack of diffusion for low-concentration boron profiles indicates that boron diffusion in amorphous silicon is driven by high concentrations. Ultrashallow high-concentration fluorine profiles diffuse quite rapidly in amorphous silicon, and like boron, undergo a definite transient enhancement. In contrast, ultrashallow high- concentration phosphorus and arsenic profiles did not significantly diffuse in our experiments.
Xafs as a Direct Local Structural Probe in Revealing the Effects of C Presence in B Diffusion in Sige Layers
Authors: Sahiner M. Alper , Ansari Parviz , Carroll Malcolm S. , Magee Charles W. , Novak Steven W. , Woicik Joseph C. 
Published: April 2011

ABSTRACTThe local structural information around the germanium atom in boron doped SiGe alloys is important in understanding the dopant diffusion mechanisms. Epitaxial SiGe test structures with B and C markers were grown on Si substrates by using rapid thermal chemical vapor deposition (RTCVD). The local structure around the Ge atom was probed using Ge K-edge x-ray absorption fine structure spectroscopy (XAFS) to determine the effects of the B and C on the Ge sites. The concentration profiles obtained from secondary ion mass spectroscopy are correlated with the Ge XAFS results. The modifications on the local structure around the Ge atoms are revealed from the multiple scattering analyses on the Ge near-neighbors. First and second shell XAFS fits to the B doped SiGe samples indicate a direct evidence of the Ge trapping of the B atoms whereas the C is randomly distributed to the Si lattice sites.
Investigation of Fluorine Effect on the Boron Diffusion by Mean of Boron Redistribution in Shallow Delta-doped Layers
Authors: Halimaoui A. , Hartmann J. M. , Laviron C. , El-Farhane R. , Laugier F. 
Published: April 2011

ABSTRACTPreviously published articles have shown that co-implanted fluorine reduces transient enhanced diffusion of boron. However, it is not yet elucidated whether this effect is due to interaction of fluorine with point-defects or boron atoms. In this work, we have used boron redistribution in a shallow Delta-doped Si structures in order to get some insights into the role of fluorine in the boron diffusion. The structures consisted of 3 boron-doped layers separated by 40nm-thick undoped silicon. The samples were given to Ge preamorphization and F co-implant. SIMS depth profiling was used to analyse boron redistribution after annealing. The results we obtained strongly suggest that fluorine is not interacting with point-defects. The reduction in boron TED is most probably due to boron-fluorine interaction.
Fabrication of p+/n Ultra Shallow Junctions (USJ) in silicon by excimer laser doping from spin-on glass sources
Authors: Coutanson S. , Fogarassy E. , Venturini J. 
Published: April 2011

ABSTRACTIn this work was investigated a simple laser doping method employing doped oxide glass films as dopant source (up to 2.1021cm−3) which are deposited onto silicon by the spin coating technique. Both short (20 ns) and long (200 ns) pulse duration excimer laser beams were used to deposit a large amount of energy in a short time onto the near-surface region. Under suitable conditions, the irradiation leads to surface melting and dopant incorporation by liquid phase diffusion from the surface. Boron distribution profiles in the two pulses duration regimes were studied as well as their electrical properties, and the junction formation of less than 20 nm in depth was demonstrated.
Study of Ge Out-diffusion During Nickel (Platinum ∼ 0, 5, 10 at.%) Germanosilicide Formation
Authors: Jin L. J. , Pey K. L. , Choi W. K. , Fitzgerald E. A. , Antoniadis D. A. , Pitera A. J. , Lee M. L. , Chi D. Z. 
Published: April 2011

ABSTRACTThe interfacial reaction between 10 nm Ni(Pt ∼0, 5, 10 at.%) and (100) Si0.75Ge0.25 substrate after rapid thermal annealing between 400 and 800°C has been studied in detail using Micro- Raman spectroscopy. Only monogermanosilicide phase was detected in the temperature range investigated. The evolution of a broad Ni(Pt)SiGe Raman peak into two distinct peaks with increasing annealing temperature is attributed to a Ge out-diffusion from the germanosilicide grains. In addition, Raman spectroscopy further proves that depletion of Ge concentration in the Ni(Pt)SiGe grains reduces at higher temperature by the addition of Pt. The above phenomena were further supported by X-ray diffraction method.
Accurate Monte Carlo Simulation of Ion Implantation into Arbitrary 1D/2D/3D Structures for Silicon Technology
Authors: Tian Shiyang , Moroz Victor , Strecker Norbert 
Published: April 2011

ABSTRACTWe present an integrated Monte Carlo implant simulator which is capable of accurately simulating ion implantation into any amorphous materials and crystalline Si for 1D/2D/3D structures with arbitrary geometry and topography. With this simulator, we investigate some practical examples which reveal interesting 2D/3D effects, and demonstrate the importance of <110> channeling for sub-100nm silicon technology.
Diffusion of Fluorine at High Concentration in Silicon: Experiments and Models
Authors: Robison Robert R. , Saavedra Antonio F. , Law Mark E. 
Published: April 2011

ABSTRACTWe have developed a model for high concentration fluorine diffusion and fluorine diffusion in amorphous silicon. In this context, we define high concentration fluorine to mean fluorine doses above the threshold of amorphization for implantation into silicon, which is approximately 1×1015/cm2 dose. We pre-amorphized with silicon to create a continuous amorphous region, and samples were subsequently implanted with the fluorine conditions of 16keV at 2×1015cm−2 dose, 30keV at 2×1014 cm−2 dose, or 16keV at 8×1015cm−2 dose. Samples were annealed by either conventional furnace or RTA with an N2 ambient for various times at temperatures of 550-750 °C. SIMS was used for depth profiling, and TEM images were also taken of the samples to check for defects and amorphous depth. We then created the model for the data by extending the fluorine model presented in our previous work, and it models the profile motion and the time dependence well. The model is also still capable of describing our previous work and fits it very well.
Interactions of Indium, Arsenic and Carbon in Silicon Using the Pseudopotential Technique
Authors: Shishkin M. , Yan A. , De Souza M. M. 
Published: April 2011

ABSTRACTFactors limiting the activation of indium in silicon are examined via the ab initio pseudopotential technique. The role of carbon in the enhancement/retardation of activation/diffusion respectively is clarified. It is found that (1) adjacent substitutional indium atoms are deactivated. Only second neighbour sites of indium are activated unlike the case of boron, where all substitutional sites remain activated. (2) Silicon self-interstitials deactivate indium by trapping them on substitutional sites. Carbon, on the other hand, traps such self- interstitials with higher binding energy and prevents them from deactivating indium. (3) Since both indium and carbon diffusion is interstitial mediated, carbon reduces indium diffusion on account of its higher binding energy with the self-interstitial. Moreover, the release of the carbon interstitial is more favourable than the release of the indium interstitial from a carbon-indium pair. Therefore, carbon minimises indium interstitial diffusion. (4) Arsenic enhances de- activation of indium by neutralisation and by strong binding on adjacent substitutional sites. Furthermore since the release of the indium interstitial is more favourable in comparison to the release of the arsenic interstitial from the indium-arsenic pair, indium diffusion is enhanced in the presence of arsenic.
Evaluation of PECVD deposited Boron Nitride as Copper Diffusion Barrier on Porous Low-k Materials
Authors: Liu J. , Wang W. D. , Wang L. , Chi D. Z. , Loh K. P. 
Published: April 2011

AbstractUltra low dielectric constant (κ) material is needed as the inter-metal dielectrics to reduce RC delay when device dimension is scaled to sub-100nm. Porous dielectric films have been considered as good candidates for the application as inter-metal dielectrics due to their ultra low-k properties. Identifying proper dielectric copper diffusion barrier on the porous low-k films is critical for the low-k/Cu damascene fabrication process. In this study, we have evaluated the compatibility of plasma-deposited amorphous Boron Nitride film as a dielectrics copper diffusion barrier on a MSQ-based porous low-k LKD5109 film (from JSR). Both microwave plasma enhanced CVD (2.45 GHz) and radio-frequency plasma enhanced CVD (13.56 MHz) were applied for the BN deposition in order to evaluate the compatibility of the two plasma processes with the porous film. Growth parameters were optimized to minimize the boron diffusion and carbon depletion in the porous low-k films, which were found to have deleterious effects on the dielectric properties of the low-k films. FTIR and micro-Raman were employed for analyzing the changes in chemical structure of the low-k films after BN growth. Capacitance-voltage measurement was used to characterize the dielectric constants of BN film on Si and the BN-deposited porous low-k film. SIMS characterization was carried out to evaluate the performance of the BN film against copper diffusion.
Ellipsometric Porosimetry of Porous Low-k Films with Quazi-Closed Cavities
Authors: Baklanov Mikhail R. , Mogilnikov Konstantin P. , Yim Jin-Heong 
Published: April 2011

AbstractEvaluation of quasi-closed cavities connected with air through narrow necks is discussed. These cavities behave as closed pores when they are studied by Positron Annihilation Lifetime Spectroscopy (PALS). The reason is a short lifetime of o-positronium (Ps) and energy barrier that exist for Ps diffusion from large pores (d>3 nm) to small ones (d<3 nm). It is shown that more comprehensive information can be obtained using adsorption porosimetry. Standard adsorptives used in adsorption porosimetry have infinite lifetime allowing complete penetration and filling all the cavities during the measurement. Calculation of the neck and cavity sizes is based on the theory of metastable adsorption phases developed by Derjagin, Broekhoff and de Boer (DBdB). Results of evaluation are in good agreement with data obtained by SEM and TEM.
A Novel Organosiloxane Vapor Annealing Process for Improving Elastic Modulus of Porous Low-k Films
Authors: Kohmura Kazuo , Oike Shunsuke , Murakami Masami , Tanaka Hirofumi , Takada Syozo , Seino Yutaka , Kikkawa Takamaro 
Published: April 2011

AbstractA novel organosiloxane-vapor-annealing method has been developed for improving the mechanical strength of porous silica films with a low dielectric constant. Treatment of a porous silica film with 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS) under atmospheric nitrogen above 350 °C significantly enhanced the mechanical strength (i.e., elastic modulus and hardness) of the film. Results of Fourier transform infrared spectroscopy (FT-IR) and thermal desorption spectroscopy (TDS) suggested the formation of cross-linked poly(TMCTS) network on the porous silica internal wall surfaces by the TMCTS treatment. Such TMCTS cross-linked network is thought to enhance the mechanical strength of the low-k film.
Three Dimensional Interconnect Stress Modeling for Back End Process
Authors: Xu Xiaopeng , Moroz Victor 
Published: April 2011

AbstractA process oriented approach is demonstrated for modeling the stress evolution during the entire back end process flow. Noad hocassumptions regarding stress states are made for layer deposition and etching. Intrinsic stresses from material formation, thermal mismatch stresses from temperature ramps, stress relaxation due to viscous deformation, and stress profile redistribution upon deposition and etching are all considered at each process. Parametric studies are carried out to examine the effects of viscous flow, material selection and layout variations. It is found that the viscous flow of the passivation and dielectric materials have large impact on stress evolution. A TCAD assisted design approach is suggested for lowering stress levels of critical stress components. The implications of the stress modeling results on reliability issues like stress-triggered void formation are discussed.
Stressmigration studies on dual damascene Cu/oxide and Cu/low k interconnects
Authors: Baek Won-Chong , Ho Paul. S. , Lee Jeong Gun , Hwang Sung Bo , Choi Kyeong-Keun , Maeng Jong Sun 
Published: April 2011

AbstractStress-induced void formation (SIV) was studied in dual damascene Cu/oxide and Cu/low k interconnects over a temperature range of 140 ∼ 350 °C. Two modes of stressmigration were observed depending on the baking temperature and sample geometry. At lower temperatures (T < 290 °C), voids were formed under the periphery of via connecting to narrow lines. This mode of stressmigration showed a typical behavior of stressmigration with peak damage at 240 °C, and an activation energy (Q) of 0.75 eV for Cu/oxide interconnects. At a higher temperature range (T > 290 °C), voids were found in via bottoms which were connected to wide lines. The rate of high temperature stressmigration increased exponentially with temperature up to 350 °C and did not show a peak at a certain temperature. The activation energy was 1.0 eV for Cu/oxide, 0.86 eV for Cu/OSG, and ∼1.0 eV for Cu/FSG interconnects. The dependence of stressmigration on linewidth, sample geometry, and ILD material is presented in this paper.
“Chlorine-based Reactive Ion Etching Process to Pattern Platinum for MEMS Applications”
Authors: Choi Sung H. , Osborn Jon V. , Morgan Brent A. 
Published: April 2011

AbstractWe have developed platinum (Pt) deposition and chlorine-based Reactive Ion Etch (RIE) processes that are needed to deposit, pattern and embed electrodes deep within a MEMS process flow. Various combinations of chlorinebased gases were tested to find the optimum gas mixture for RIE. A 1: 0.4 mixture ratio of pure chlorine to argon and 100-150 Watts of RF microwave power were found to be optimum conditions for the RIE of platinum metal. The addition of argon gas to chlorine was found to contribute to the anisotropic etching of platinum, obtaining vertical shaped sidewall patterns. A simple model of the platinum etching mechanism is proposed. Following the plasma enhanced formation of platinum and chlorine ions, volatile products of platinum chlorides were formed and driven away at elevated temperature. As a demonstration of our RIE process, micron-sized platinum patterns with vertical sidewalls were fabricated. Etch chemistry was investigated using ToF SIMS analysis. This etch technique will be useful to device developers intending to use the unique properties of platinum metal as an electrode that is deeply embedded within a MEMS process flow.
Low Temperature Poly-Si TFT Technology
Authors: Noguchi T. , Kim D.Y. , Kwon J.Y. , Park K.B. , Jung J.S. , Xianyu W.X. , Yin H.X. , Cho H.S. 
Published: April 2011

AbstractLow temperature poly-Si TFT technology is reviewed and is discussed from a view point of device, fabrication process, and its possibility as FPD (Flat Panel Display) application. After the appearance of crystallization technique of SPC (Solid Phase Crystallization) using FA (Furnace Annealing) or ELA (Excimer Laser Annealing) using UV (Ultra-Violet) beam, the electronic property of poly-Si thin-film, which relates to the crystalinity of the grains, was improved drastically, and the process temperature for the TFT fabrication had been reduced below 600° down to 400°. As a result, improvement of device characteristic of poly-Si TFT such as an enhancement of carrier mobility or a reduction of leakage current has been studied intensively for the application to FPD (Flat Panel Display) on glass. Currently, extensive study is being done in order to realize a more functional SOG (System on Glass). By reducing the TFT process temperature down to 200° or below and by modifying a design for the device structure or the circuit in the pixel, O-LED (Organic LED) FPD addressed by uniform poly-Si TFTs is expected to mount on flexible plastic substrate such as on PES (PolyEtherSulphone). The poly-Si TFT has a possibility to develop as a smart system on plastic panel for unique applications as well as the conventional Si LSI in the ubiquitous IT (Information Technology) era.
Poly-Si TFTs From Glass to Plastic Substrates: Process and Manufacturing Challenges
Authors: Lemmi F. , Lin S. , Drews B.C. , Hua A. , Stern J.R. , Chung W. , Smith P.M. , Chen J.Y. 
Published: April 2011

AbstractPoly-Si Thin-Film Transistors (TFTs) are currently used in commercial active-matrix displays. They provide superior performance with respect to their amorphous silicon counterparts and allow integration of driving electronics directly on the display glass plates.For several applications, it can be desirable to have active-matrix displays made on flexible substrates. However, a direct application of a standard TFT process to plastic substrates is not in general possible, mostly because of temperature limits and related dimensional stability issues. In addition, standard flat-panel manufacturing tools are not capable of automatically handling non-rigid floppy substrates.Therefore, a new process has to be developed, compatible with a suitable way of handling plastic substrates. A process was developed in which plastic sheets are laminated on glass carrier wafers and run through all the automated tools. A low-temperature process using excimer laser annealing is developed and optimized. High-quality TFT backplanes are manufactured with a pixel layout designed for active-matrix OLED (AMOLED) displays. Field-effect mobility in excess of 70 cm2Vs on p-channel TFTs are achieved, together with leakage currents lower than 2 pA per micron gate width.Challenges include low-temperature gate dielectric development, reduction of intrinsic film stress, protection of plastic from laser damage, and contact formation. Solutions to these challenges are discussed and TFT transfer characteristics on glass and plastic substrates are presented. Finally, images from prototype monochrome AMOLED displays are presented, with 64 × 64 pixels and 80-dpi resolution.