bluuebunny/crossref_metadata_2025_split huggingface dataset:
Morphological Control of Diamond Thin Films: Its Influence on Friction and Wear
Authors: Yee Andrew L. , Ong Hockchun , Chang R. P. H. 
Published: April 2011

ABSTRACTMicrowave plasma enhanced chemical vapor deposition was used to grow diamond films with different morphologies and surface roughnesses. With the proper choice of deposition parameters (111) faceted, octahedral, flat (100) and microcrystalline diamond films were obtained. Scanning electron microscopy, atomic force microscopy and stylus profilometry were used to assess the surface topography for each type of film. Raman spectroscopy and x-ray diffraction were also used to determine the purity of the diamond phase and growth orientation of the films, respectively. Single pass friction and wear tests were conducted on each film in order to determine the effect of surface morphology on the coefficient of friction and wear of the counterface materials and/or diamond films. Counterface materials included alumina, tungsten carbide, zirconia, and the (100) face of a synthetic diamond single crystal. Results showed a decrease in the coefficient of friction as the film roughness decreased. Specific wear of the non-diamond counterface materials showed a marked decrease for the flatter and smoother diamond surfaces. For diamond on diamond, the coefficient of friction also decreased as film topography became smoother. Wear of the diamond films occurred by fracture or shearing of asperity tips which was most severe for the rougher films. Control of diamond morphology is shown to be of paramount importance in tribological applications in order to reduce abrasive wear, material transfer, and diamond film fracturing.
Mechanical Properties of Diamond Fibres
Authors: Everitt N. M. , Shatwell R. A. , Kalaugher E. , Nicholson E. 
Published: April 2011

ABSTRACTTungsten and silicon carbide fibres have been coated with diamond using the HFCVD technique. The diamond volume fraction varied between 26% and 73%. Resonance in bending tests gave a Young's modulus of 880 GPa for the diamond coating. Tensile testing indicated that the diamond fracture strength was between 600 MPa and 2000 MPa, depending on the coating thickness, and thus the grain size, of the diamond. The strain to failure of the diamond coating in bending was approximately 0.15% for 25 μm thick films.
Transient And Spatial Radiative Properties Of Patterned Wafers During Rapid Thermal Processing
Authors: Wong Peter Y. , Miaoulis Ioannis N. , Madras Cynthia G. 
Published: April 2011

AbstractTemperature measurements and processing uniformity continue to be major issues in Rapid Thermal Processing. Spatial and temporal variations in thermal radiative properties of the wafer surface are sources of non-uniformities and dynamic variations. These effects are due to changes in spectral distribution (wafer or heat source), oxidation, epitaxy, silicidation, and other microstructural transformations. Additionally, other variations are induced by the underlying (before processing) and developing (during processing) patterns on the wafer. Numerical simulations of Co silicidation that account for these factors are conducted to determine the radiative properties, heat transfer dynamics, and resultant processing uniformity.
A Universal Thermal Module™ for Clusterable RTP and MOCVD Applications
Authors: Moslehi Mehrdad M. , Omstead Tom , Lee Yong Jin , Kermani Ahmad , Velo Lino , Schaper Charles 
Published: April 2011

AbstractA Universal Thermal Module™ (UTM™) has been developed for vacuum-integrated cluster RTP and MOCVD as well as stand-alone atmospheric RTP applications. The UTM™ architecture provides highly modular RTP and MOCVD tool configurations for various single-wafer thermal processes. The UTM™ design comprises a temperature-controlled UHV-grade process chamber as well as an ultraclean gearless wafer rotation assembly for improved temperature uniformity and enhanced built-in reliability. The UTM™ RTP employs bottom/backside wafer heating using a multi-zone axisymmetric illuminator and a reflective multi-zone gas showerhead located above the wafer. Precision RTP control is achieved using a multi-zone controller in conjunction with a multipoint sensor system with real-time multi-zone compensations for wafer emissivity and illuminator light interference effects. The RTP temperature measurement and control techniques fully compensate for any axisymmetric or non-axisymmetric wafer emissivity patterns, eliminating the need for pre-RTP wafer backside conditioning. The UTM™ showerhead provides capabilities for ultraclean multi-zone gas injection and in-situ RF plasma for MOCVD and RTCVD processes. The UTM™ MOCVD module meets the most stringent specifications and tool parameters for various metallization and high-K dielectric deposition applications. This module has been used for deposition of low-resistivity copper films with excellent void-free sub-half-micron gap fill for high-performance multilevel interconnects. The UTM™ RTP and MOCVD modules have been implemented based on design optimizations in a virtual reactor environment.
High Temperature Thermal Processing for Ulsi Applications
Authors: Reid Kimberly G. , Sitaram A. R. 
Published: April 2011

AbstractThe diversity of semiconductor manufacturing as well as the decreasing thermal budget for ULSI devices has driven semiconductor equipment manufacturers to develop and improve thermal processing solutions. Recent advances include new temperature measurement systems for rapid thermal processors (RTP), the development of the small batch fast ramp furnace (SBFR), as well as improved capability and load size in the conventional vertical batch furnace (BF). This paper will review the RTP, SBFR, and batch furnace for typical atmospheric front end of the line applications. Throughput and cycle time will be modeled for each type of system. Sematech's cost of ownership model will be employed to evaluate the relative importance of throughput, mean time between failure, and equipment cost. And finally an overview discussion of the issues associated with temperature measurement and system configurations of the RTP will be given.
High Quality Ultrathin Gate Dielectrics Prepared by In-Situ RTP
Authors: Han L. K. , Bhat M. , Yan J. , Wristers D. , Kwong D. L. 
Published: April 2011

AbstractThis paper reports on the formation of high quality ultrathin oxynitride gate dielectric by in-situ rapid thermal multiprocessing. Four such gate dielectrics are discussed here; (i) in-situ NO-annealed SiO2, (ii) N2O- or NO- or O2-grown bottom oxide/RTCVD SiO2/thermal oxide, (iii) N2O-grown bottom oxide/Si3N4/N2O-oxide (ONO) and (iv) N2O-grown bottom oxide/RTCVD SiO2/N2O-oxide. Results show that capacitors with NO-based oxynitride gate dielectrics, stacked oxynitride gate dielectrics with varying quality of bottom oxide (O2/N2O/NO), and the ONO structures show high endurance to interface degradation, low defect-density and high charge-to-breakdown compared to thermal oxide. The N2O-last reoxidation step used in the stacked dielectrics and ONO structures is seen to suppress charge trapping and interface state generation under Fowler-Nordheim injection. The stacked oxynitride gate dielectrics also show excellent MOSFET performance in terms of transconductance and mobility. While the current drivability and mobilities are found to be comparable to thermal oxide for N-channel MOSFET's, the hot-carrier immunity of N-channel MOSFET's with the N2O-oxide/CVD-SiO2/N2O-oxide gate dielectrics is found to be significantly enhanced over that of conventional thermal oxide.
Temperature Dependence of Nitrogen Accumulation at SiO2/Si by N2O- and by NO-Oxidation
Authors: Weidner G. , Kröger D. , Weidner M. , Tittelbach-Helmrich K. 
Published: April 2011

AbstractThis paper investigates conditions of low thermal budget N2O and NO oxidation with simultaneous accumulation of 0.5 to 1 at% nitrogen at the SiO2/Si interface of thin oxide layers. A nitrogen accumulation model is presented. It is concluded that the nitrogen accumulation should be realized with oxidizing conditions at the interface to silicon and it is proposed to control the NO partial pressure in reactor gas for the desired nitrogen amount at tolerable thermal budget.
Initial Growth of Polycrystalline Si and GeSi Alloys in an RTP System
Authors: Rem J. B. , Salm C. , Klootwijk J. H. , Weusthof M. H. H. , Holleman J. , Verweij J. F. 
Published: April 2011

AbstractThe initial growth of polycrystalline silicon (Si) and germanium-silicon alloys (GexSi1−x) from SiH4 and GeH4, where x is in the range of 0-0.4, in an RTMP reactor has been investigated using an in situ monitoring technique called reflectometry. An inhibition time is found which, for poly-Si in the temperature range of 550–650°C decreases with increasing temperature and for poly-GexSi1−x in the temperature range of 500–625°C shows the same behavior. The effect of total pressure, ranging from 0.10–1.20 mbar, is even stronger: an increasing pressure sharply decreases the inhibition time. For a selective deposition a low SiH4 and GeH4 partial pressure seems favorable, while for a non-selective deposition of poly-GexSi1−x alloys on (gate) oxides (for Thin Film Transistor applications) a high pressure or a pressure pulse at the start of the deposition process can be used.
Successful Preparation of High Frequency HBT by Integrated RTCVD Processes
Authors: Ritter G. , Tillack B. , Knoll D. 
Published: April 2011

AbstractComplete epitaxial Si-SiGe-Si- stacks with a defined doping profile for each component have been deposited on Si substrates from the system SiH4, GeH4, H2, B2H6, PH3 by RTCVD. The deposition has been carried out at a temperature of 650°C for Si and of 500°C for SiGe, respectively, both at a pressure of 2 mbar. The developed epitaxial process including an effective H2 in-situ preclean annealing has been integrated in a simple double mesa technology for the preparation of SiGe base heterojunction bipolar transistors (HBT). Despite the simplicity of the technology and the lithographical level allowing emitter dimensions of 2.3×2.5 μm2 only, test devices on 4” wafers reached transit frequencies fT and maximum oscillation frequencies fmax of higher than 60 GHz and 30 GHz, respectively. Besides, a low base current has been measýnl as proof for a good layer quality.
A New Flexible Rapid Thermal Processing System
Authors: Saraswat K. C. , Chen Y. , Degertekin L. , Khuri-Yakub B. T. 
Published: April 2011

AbstractA highly flexible Rapid Thermal Multiprocessing (RTM) reactor is described. This flexibility is the result of several new innovations: a lamp system, an acoustic thermometer and a real-time control system. The new lamp has been optimally designed through the use of a “virtual reactor” methodology to obtain the best possible wafer temperature uniformity. It consists of multiple concentric rings composed of light bulbs with horizontal filaments. Each ring is independently and dynamically controlled providing better control over the spatial and temporal optical flux profile resulting in excellent temperature uniformity over a wide range of process conditions. An acoustic thermometer non-invasively allows complete wafer temperature tomography under all process conditions - a critically important measurement never obtained before. For real-time equipment and process control a model based multivariable control system has been developed. Extensive integration of computers and related technology for specification, communication, execution, monitoring, control, and diagnosis demonstrates the programmability of the RTM.
Rapid Isothermal Annealing of Doped and Undoped Spin-on Glass Films
Authors: Slaoui A. , Ventura L. , Lachiq A. , Monna R. , Muller J. C. 
Published: April 2011

AbstractThe rapid thermal annealing of doped (SOD) and undoped (SOG) glass films spinned onto silicon from diluted or undiluted solutions has been investigated. The dilution performed by methanol has allowed to obtain oxide films as thin as 10 nm.The optical measurements of annealed SOG films have shown that good oxide films without oxygen deficiency are achievable. The electrical characteristics of Al-gate capacitors assessed by Capacitance-voltage measurements have shown a great dependence of the water content in the range of 600–850°C before reaching a typical dielectric constant value near 3.8 at higher temperatures. Low Interface state densities values obtained at temperature up to 900°C confirm the curing effect of a rapid thermal annealing.On the other hand, we have demonstrated that the efficiency of rapid thermal diffusion from boron or phosphorus SOD films deposited on Si wafers depends on the source composition and its thickness. In particular, we have shown that it is possible to control the junction depth, the surface concentration and the minority-carrier diffusion length by varying the amount of dopant concentration in the solution, the thickness of the doped oxide film and the rapid thermal processing parameters. Futhermore, the remaining doped SOG film can play the role of an efficient oxide passivation layer.
Formation of Ultra-Shallow Junctions in Silicon by Rapid Thermal Vapor Phase Doping in an Ultrahigh Vacuum Rapid Thermal Processing System
Authors: O'neil Patricia A. , Violeite Katherine E. , Öztürk Mehmet C. , Ivanov Igor C. 
Published: April 2011

AbstractIn this work, we have studied the formation of ultra-shallow p-type junctions by rapid vapor phase doping. The doping process was performed in an ultra high vacuum rapid thermal processing system using 0.1 l/min of a B2H6/H2 mixture. The B2H6 content of the mixture was only. 500 ppm corresponding to a B2H6 flow of 50 μl/min. In contrast, previous work in conventional and rapid thermal processing systems used B2H6 flows as high as 0.1 l/min which tend to form either pure boron or boron silicide layers depending on the processing conditions. In this study we exposed 4″, (100) oriented, n- and p-type silicon wafers to the B2H6/H2 mixture for varying growth conditions. Boron junction profiles were obtained at temperatures ranging from 650°C to 850°C. Boron dose, peak concentration, and junction depth were found as a function of growth temperature and time. Our results show that ultra-shallow (≤ 500 Å) boron profiles with surface concentrations above 1020 cm−3 can be obtained in Si at temperatures as low as 650°C. Typical process times range from 15 to 90 seconds making the process a good candidate for single wafer manufacturing in rapid thermal processing systems.
Ultra-Shallow Raised P+N Junctions with Self-Aligned Titanium Silicide Contacts formed by Boron Outdiffusion from Selectively Deposited Silicon Epitaxial Layers
Authors: Shih H. T. , Violette K. E. , Öztürk M. C. 
Published: April 2011

AbstractIn this study, we have fabricated ultra-shallow p+n junctions by boron outdiffusion from selectively deposited Si epitaxial layers. The undoped layers (900 – 1000 Å) were selectively deposited on active areas in a UHV-RTCVD reactor using Si2H6 and Cl2 at 800°C and at a total pressure less than 30 mTorr. Junctions were formed by BF2 ion-implantation into epitaxial layers with and without Ge preamorphization followed by RTA at 1000°C and 1050°C for 10 s in Ar. Junction depths ranging from 400 Å to 700 Å were formed at a background concentration of l×1016 cm−3. Abrupt boron profiles with epitaxy/substrate interface concentrations on the order of 1020 cm-3 were formed. Self-aligned TiSi2 was formed at four different thicknesses by evaporating 100, 200, 300 or 400 Å thick Ti followed by a two-step RTA cycle with a selective etch between to remove the unreacted Ti on Si02. Our results show that raised junctions with a Ti thickness of 400 Å (corresponding to a TiSi2 thickness over 900 Å and consumption of the entire epitaxial layer) exhibit a reverse leakage of less than 10 pA for a device area of 800×800 μm2. This corresponds to areal and peripheral leakage current densities of 67 pA/cm2 and 4 pA/cm. Therefore, thick silicide layers can be used on raised junctions reducing the junction sheet resistance and eliminating the possibility of silicide agglomeration. Furthermore, implantation damage in substrate is eliminated by confining the implant into the raised region which is later consumed during silicide formation.
Silicon Etching in Rapid Thermal Chemical Vapor Deposition of Tisi2
Authors: Ren Xiaowei , Gladden Dannellia B. , Öztürk Mehmet C. , Batchelor A. Dale 
Published: April 2011

AbstractDownscaling of microelectronics devices into the deep submicron regime requires ultrashallow junctions with reliable, low-resistivity contacts. The conventional self-aligned TiSi2 technology exhibits a serious limitation in forming contacts to ultra-shallow junctions due to silicon substrate consumption. Selective chemical vapor deposition of TiSi2 is being investigated because of its potential for overcoming this difficulty. In this process Si and Ti are supplied from the gas phase. The standard source gas for Ti has been TiCl4 while several gases including SiH4, Si2H6 and SiH2Cl2 are available for Si. The reports on this process indicate that optimized process conditions can deliver TiSi2 films without substrate consumption. Although this promise is significant, the deposition has a complicated chemistry involving processes such as silicon etching, silicon consumption or silicon pedestal deposition taking place along with TiSi2 deposition. Although, suppression of Si-substrate etching by excess H2 has been reported previously, a broad quantitative analysis has been lacking up until this reporting. In this work, we have examined silicon etching trends as a function of temperature for different H2:TiCl4 flow ratios using thermodynamic equilibrium calculations. We have also performed experiments in a lamp heated rapid thermal chemical vapor deposition reactor to study substrate etching over the temperature range of 600°C to 800°C and for H2 flows from 0 to 1000 sccm. A silicon conversion efficiency is defined as a measure of the amount of Si converted to TiSi2 relative to total Si used from the substrate and it is evaluated via both thermodynamic calculations and experiments with good agreement between the two. Our calculations suggest that at high temperatures, etching occurs mainly via formation of SiCl2. Addition of H2 into the reaction chemistry encourages formation of HCl reducing the amount of Cl available for SiCl2 formation responsible for substrate etching. Our results show that by optimizing the H2 flow rate and the process temperature silicon substrate etching can be effectively suppressed.
Monte-Carlo simulation of the deposition process in PVD-technology
Authors: Lugscheider E. , Knotek O. , Löffler F. , Schnaut U. , Eckert P. 
Published: April 2011

AbstractThe Magnetron Sputter Ion Plating (MSIP) technology has been applied in a wide range of modern technological fields, due to the virtually unlimited potential of coating and substrate materials. However, up to now, the development of optimization has been depending mainly on empiricism and experiments.Energies and the directions of the particles sputtered with various ejection angles and initial energies from the target surface are changed due to collisions with gas atoms during their movement within the sputtering chamber. Therefore the particles have a distribution of incident energies and angles which have a great influence on structure and properties of thin film coatings. This paper describes computer investigations to simulate the motions of the particles from target to substrate using a Monte-Carlo method and a binary collision approximation. The applied model takes into account non-uniform sputtering effects of the target in the MSIP process due to the magnetic field and the erosion zone.
Deposition Profile Simulation: Topological Effects
Authors: Wang Yun Biao , Teyssandier Francis 
Published: April 2011

ABSTRACTThere is a considerable amount of evidence for the dependence of microstructure and surface morphology of films obtained by conventional thermally activated chemical vapor deposition on mass transport phenomena. This paper addresses the simulation of the influence of conveclive-diffusivc transport phenomena as well as homogeneous reactions on the deposition profile of silicon films in the case of some characteristic topological effects. For that purpose, the Si-H chemical system including both homogeneous and heterogeneous reactions is used. The evolution of the deposition profile during vapor growth is simulated for various surface defects such as a step or a trench. The influence of basic processing parameters such as temperature or flowrate is discussed.
Elastic Analysis of Twinning in Misfitting Thin Films
Authors: Sridhar N. , Rickman J.M. , SroIovitz D.J. 
Published: April 2011

ABSTRACTWe examine the conditions under which a misfitting thin film on a substrate will twin and the pattern of the twin microstructure that will form. Using linear elasticity theory, we present exact analytical results for the energy released due to the formation of a periodic array of twinned domains as well as that for a single embedded twin domain. While the analysis is applicable to general misfit strain tensors, we specifically analyze the energetics of twinned domain formation for a tetragonal film on a cubic substrate. The analysis shows that for a periodic distribution of twins, the equilibrium width of the domains of the two variants are identical. Our results also show that the equilibrium periodicity of the microstructure scales inversely with film thickness for large film thickness and decays exponentially with increasing film thickness for small film thicknesses.
Simulation Studies of TiN PVD and CVD Thin Films for Contact/Via Liners
Authors: Bang D.S. , McVittie J.P. , Saraswat K.C. , Iacoponi J.A. , Gray J , Krivokapic Z. , Littau K. A. 
Published: April 2011

ABSTRACTTiN PVD and CVD models have been incorporated in the SPEEDIE topography simulator. A parameter extraction methodology is presented which allows engineers to locally calibrate their process to the SPEEDIE simulator. The calibration requires no special equipment or modifications to the PVD or CVD equipment. Parameter extraction is demonstrated with Applied Materials deposition equipment.
Carbon Atom, Dimer and Trimer Chemistry on Diamond Surfaces from Molecular Dynamics Simulations
Authors: Valone Steven M. 
Published: April 2011

ABSTRACTSpectroscopic investigations of various atmospheres appearing in diamond film synthesis suggest evidence for carbon atoms, dimers or trimers. Molecular dynamics simulations with the Brenner hydrocarbon potential are being used to investigate the elementary reactions of these species on a hydrogen-terminated diamond (111) surface. In principle these types of simulations can be extended to simulations of growth morphologies, in the 1-2 monolayer regime presently.
Residual Stresses in Tungsten Lines: Analysis of Experimental- (Micro-Raman Spectroscopy, Xrd) and Numerical Results
Authors: De Wolf I. , Maes H.E. , Moffet J. , Ignat M. 
Published: April 2011

AbstractMicro-Raman spectroscopy, XRD, and analytical modelling are used to study stresses in and surrounding tungsten lines of different widths and spacing. The stress in the lines and in the adjacent substrate is calculated using a concentrated- and a distributed edge force model. Both models are adapted such that the substrate-stress components can also be calculated for an array of lines. The results from XRD and micro-Raman spectroscopy and the results from the distributed edge force model are in agreement. The combination of data from the two experimental techniques is shown to give some important feed-back to the theoretical models.