bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integrated Processinyg of Silicided Shallow Junctions using Rapid Thermal Annealing Prior to Dopant Activation
Authors: Rubin Leonard , Herbots Nicole , Gutierrez JoAnne , Hoffman David , Ma Di 
Published: March 2011

ABSTRACTA method for producing shallow silicided diodes for MOS devices (with junction depths of about 0.1 µm), by implanting after forming the silicide layer was investigated. The key to this integrated process is the use of rapid thermal annealing (RTA) to activate the dopants in the silicon, so that there is very little thermal broadening of the implant distribution. Self-aligned titanium silicide (TiSi2) films with thicknesses ranging from 40 to 80 nm were grown by RTA of sputter deposited titanium films on silicon substrates. After forming the TiSi2, arsenic and boron were implanted. A second RTA step was used after implantation to activate these dopants. It was found that implanting either dopant caused a sharp increase in the sheet resistivity of the TiSi2. The resistivity can be easily restored to its original value (about 18 µΩ-cm) by a post implant RTA anneal. RBS analysis showed that arsenic diffuses rapidly in the TiSi2 during RTA at temperatures as low as 600°C. SIMS data indicated that boron was not mobile up to temperatures of 900°C, possibly because it forms a compound with the titanium which precipitates in the TiSi 2. Coalescence of TiSi2 occurs during post implant furnace annealing, leading to an increase in the sheet resistivity. The amount of coalescence depends on the film thickness, but not on whether or not the film had been subject to implantation. Spreading resistance profiling data showed that both arsenic and boron diffused into the TiSi2 during furnace annealing, reducing the surface concentrations of dopant at the TiSi2/Si interface. Both N+/P and P+/N diodes formed by this technique exhibited low leakage currents after the second RTA anneal. This is attributed to removal of the implant damage by the RTA. In summary, the second RTA serves the dual purpose of removing implant damage in the TiSi2 and creating the shallow junction by dopant activation.
Rapid Thermal Process Integration
Authors: Calder I.D. , Naem A.A. 
Published: March 2011

ABSTRACTA manufacturable process must be designed with device integrity and reliability in mind. The optimum cumulative thermal budget should be chosen to achieve a shallow junction (for performance optimization) while minimizing junction leakage. At the same time the processing must satisfy reliability requirements such as good metal step coverage and oxide integrity. Interactions between thermal processes create problems such as repeated anneals, chemical reactions, pattern shifts, and non-equilibrium conditions, as well as opportunities for process simplification, such as greater flexibility in anneal and silicidation processes. In general RTP integration requires a redesign of the complete process sequence.
Epitaxial Growth of NiSi2 and CoSi2 on Laterally Confined Silicon by Rapid Thermal Annealing
Authors: Hsu H.F. , Chu J.J. , Chen L.J. 
Published: March 2011

ABSTRACTEpitaxial growth of NiSi2 and CoSi2 on silicon inside miniature oxide openings by rapid thermal annealing has been studied. Effects of lateral confinement, including two-dimensional and linear oxide openings, as well as deposition methods on the growth of NiSi2 and CoSi2 on silicon were investigated. Vast difference found in the behaviors of the growth of epitaxy inside oxide openings between samples with the metal films deposited by electron beam evaporation and sputtering are attributed to the differences in the geometrical configuration of the films and stress levels as well as surface cleanliness.
A Self-Aligned Silicide Technology using Ion-Beam Mixing, Doped Silicide, and Rapid Thermal Processing
Authors: Ku Y. H. , Lee S. K. , Kwong D. L. , Chu P. 
Published: March 2011

ABSTRACTA SALICIDE process is described in this paper, in which ion-beam mixing is used for silicide formation, and doped silicide in conjunction with RTA drive-in are used for shallow silicided junction formation. Fundamental issues related to this process have been investigated, including (i) effects of ion-beam mixing and RTA on the properties of Ti SALICIDE and the interaction between Ti and SiO2; (ii) the self-aligned TiNxOy TiSi2 contact barrier formation and phase transformation; (iii) the mechanism of impurity rediWstrbution and segregation, and junction formation during RTA drive-in; and (iv) the performances and reliability of fabricated SALICIDE devices. Results show that this process may have a great impact on future VLSI technology.
Nucleation Phenomena during Titanium Silicon Reaction
Authors: Raaijmakers Ivo J.M.M. , Ijzendoorn Leo J. van , Theunissen Anton M.L. , Kim Ki-Bum 
Published: March 2011

ABSTRACTIt is known that thermal annealing of Ti and amorphous (α) Si first results in an amorphous silicide, after which the crystalline disilicide grows under diffusion control. The situation with respect to the reaction of Ti with crystalline (x) Si is much less clear. We have investigated the reaction of Ti with xSi with (high resolution) cross-section transmission electron microscopy and in-situ Rutherford backscattering spectroscopy. It is shown that an amorphous silicide can also be formed on crystalline Si. The presence of this amorphous silicide as a precursor to the C49TiSi2 phase is suggested to be an important issue in the nucleation and growth of the disilicide.
Process Uniformity and Electrical Characteristics of Thin Gate Dielectrics Grown by Ramped-Temperature Transient Rapid Thermal Oxidation of Silicon
Authors: Moslehit Mehrdad M. , Kermani Ahmad 
Published: March 2011

ABSTRACTRapid thermal oxidation (RTO) of Si using transient linearly-ramped-temperature saw-toothed (LRT-ST) and triangular (LRT-TA) thermal cycles has been examined through evaluations of the process uniformity, slip dislocation patterns, and electrical characteristics of MOS devices. The strong effects of the thermal cycle parameters on process uniformity and slips indicate that the overall performance of an RTP tool must be specified both under the steady-state and transient thermal cycles. The electrical characteristics of MOS devices with LRT-grown gate oxides are comparable to those for devices with oxides grown by the trapezoidal thermal cycles.
Kinetics of Rapid Thermal Oxidation : Critical Analysis of Experimental Results
Authors: Dilhac J-M. 
Published: March 2011

ABSTRACTIn this paper, we present experimental kinetics data from the literature, and the large discrepancies between them is discussed. An analytical equation for oxide thickness vs. oxidation time and temperature, adequatly describing thin film growth, is used to estimate the temperature error likely to explain the discrepancy between the above data. We also assess this error by considering the temperature sensors.
Contactless Measurements of the Surface Recombination Velocity of P—N and High—Low (P—P+, N—N+) Junctions Fabricated by Rapid Thermal Processing
Authors: Usami A. , Yamada N. , Matsuki K. , Takeuchi T. , Wada T. 
Published: March 2011

ABSTRACTA photoconductive decay curve is analyzed theoretically to determine the surface recombination velocity and the bulk lifetime separately. And it can be applied to experimental photoconductive decay curves using the reflectance microwave probe method. Then it is verified numerically and experimentally to lower the effective surface recombination velocity at p—n and high—low junctions. The high—low junctions used in this study were fabricated from the ionimplanted wafer by rapid thermal annealing or furnace annealing. Then it is shown that the measurement system in relation to surface recombination can apply to evaluations in the ion implantation and its annealing process.
The Correlation between Quantitative Surface Metallic Contamination and RTP-Induced Surface Defects
Authors: Hockett R. S. 
Published: March 2011

ABSTRACTRecent studies have shown that surface metals, introduced by scraping metals either on the silicon wafer front or back surface, can contribute to surface crystalline defects during rapid thermal processing (RTP). These studies have been qualitative in the sense that the quantitative amount of surface metallic contamination was unknown. The work involved here uses Total reflection X-Ray Fluorescence (TXRF) analysis to quantitate the surface metallic contamination on silicon wafers from cleaning (rather than scraping) both before and after RTP. In this study there was no correlation found between surface copper (ranging from 2 to 200 ×1012 atoms/cm2) and surface defects after a RTP of 600°C for 30 seconds in argon, nor was there a correlation between temperature (ranging from 600°C to 1150°C) of the RTP (120 seconds in argon) and surface defects for constant surface copper of about 30×1012 atoms/cm2. The data also revealed the introduction of cross contamination of tungsten to the frontside surface of silicon wafers when air was used as the ambient with an activation energy of 0.8 eV for RTP of 120 seconds in air with temperatures ranging from 500°C to 1000°C. This cross contamination is presumed to come from prior tungsten silicide RTP, even though the quartz tube was etched before this study. Furthermore, the cross contamination of Ga and As occurred to the wafer backsides with no apparent activation energy, and this contamination is presumed to come from prior GaAs annealing several months before.
Anomalous Transient Diffusion of Ion Implanted Boron during Rapid Thermal Annealing
Authors: Kim Y. M. , Lo G. Q. , Kwong D. L. , Tseng H. H. , Hance R. 
Published: March 2011

ABSTRACTEffects of defect evolution during rapid thermal annealing (RTA) on the anomalous diffusion of ion implanted boron have been studied by implanting silicon ions prior to boron implantation with doses ranging from 1 × 1014cm−2 to 1 × 1016cm−2 at energies ranging from 20 to 150 KeV into silicon wafers. Diffusion of boron atoms implanted into a Si preamorphized layer during RTA is found to be anomalous in nature, and the magnitude of boron displacement depends on the RTA temperature. While RTA of preamorphized samples at 1150°C shows an enhanced boron displacement compared to that in crystalline samples, a reduced displacement is observed in preamorphized samples annealed by RTA at 1000°C. In addition, low dose pre-silicon implantation enhances the anomalous displacement significantly, especially at high RTA temperatures (1 150°C). Finally, the anomalous diffusion is found to depend strongly on the defect evolution during RTA.
Thermal Stability of Zinc and Selenium Implanted GaAs
Authors: Tang A C T , Sealy B J , Rezazadeh A A 
Published: March 2011

ABSTRACTWe have observed for the first time reversible changes in the sheet carrier concentration of the rapid thermally annealed Se and Zn implanted GaAs samples during subsequent heat treatments. The electrical profiles of the implanted samples have also been modified during the annealing processes. By observing the initial rate of change in the carrier concentration, an activation energy of about 2 eV is obtained which is thought to correspond to the diffusion of gallium atoms/vacancies.
Electrical Properties of Si/SiGe Structures Grown by Low Temperature Epitaxy
Authors: Temkin H. , Green M. L. , Brasena D. , Bean J. C. 
Published: March 2011

ABSTRACTSi/SiGe heterostructures offer improved performance for many electronic and optoelectronic Si devices. The expected improvement in device characteristics depends critically on the structural perfection and precise compositional control of the epitaxial layers. This implies a combination of abrupt interfaces, on the order of 10 Å, capability of maintaining high doping levels, in the 1019 cm−3 range, with a similar spatial resolution, and low density of electrically active defects. These requirements are particularly stringent in the case of Ge-rich alloys for which the critical layer thicknesses are below ∼100 Å. The desired characteristics can be obtained by low temperature techniques such as molecular beam epitaxy (MBE) and rapid thermal chemical vapor deposition (RTCVD).
Amorphization and Annealing of 6H SiC Implanted with N-Type, P-Type or Isovalent Dopants
Authors: Spitznagel J. A. , Wood Susan , Choyke W. J. , Devaty R. P. , Ruan J. 
Published: March 2011

Abstractlons of boron, phosphorous, titanium and neon were implanted into (0001) oriented 6H SiC crystals at 300 K. Implantation energies and fluences were chosen to produce equal (calculated) displacements per atom at similar peak damage depths and a randomized (metaminct or amorphous) zone extending to the front surface. RBS/channeling was used to test the amorphization criteria. Dopant effects on regrowth kinetics and microhardness have been determined by isochronal annealing.
In-Situ Measurement of Ion Beam Induced Deposition of Gold
Authors: Dubner A. D. , Wagner A. 
Published: March 2011

Abstractmechanistic model of the ion beam induced deposition (IBID) process is proposed, and an experimental system for measuring IBID is described. In IBID, the kinetic energy of the incident ion is deposited in the substrate surface resulting in the ejection of atoms (sputtering), and the decomposition of adsorbed molecules. Net deposition occurs when the number of atoms added through decomposition exceeds the number removed by sputtering.Gold films were deposited by decomposing dimethyl gold hexafluoroacetylacetonate (C7H7F6O2Au) molecules with a 5 keV argon ion beam. The beam current density was 5 μA/cm2. These films were deposited on quartz crystal microbalances (QCM). The QCM's provide an in-situ measurement of the deposition rate as a function of ion dose, dose rate, gas pressure, and substrate temperature. The mass of the depositing film increases with increasing ion dose. The deposition yield, or mass deposited per incident ion, is independent of the power input of the ion beam and therefore, the decomposition is not due to macroscopic heating. The deposition yield is shown to depend on the sputter yield of the substrate. The yield increases with increasing gas pressure and decreasing substrate temperature. This increase is proportional to the adsorption of the organometallic gas.
Lateral Confinement of Silicide Layers Synthesized with High Dose Implantation and Annealing
Authors: White Alice E. , Short K. T. , Berger S. D. , Huggins H. A. , Loretto D. 
Published: March 2011

AbstractUsing mesotaxy, a technique which involves high dose implantation followed by high temperature annealing, we have created narrow wires of CoSi2 buried beneath the surface of a silicon wafer. The implantation masks are fabricated directly on the silicon substrate using high resolution electron beam lithography in combination with reactive ion etching. TEM analysis shows that the wires are single-crystal and oriented with the substrate with very abrupt interfaces. The electrical continuity of the wires has been confirmed with electron-beam-induced current measurements.
Back Channel Degradation and Device Material Improvement by Ge Implantation
Authors: Namavar F. , Buchanan B. , Cortesi E. , Sioshansi P. 
Published: March 2011

AbstractBecause of potential “back channel” leakage problems in silicon-oninsulator (SOI) metal-oxide-semiconductor (MOS) devices, especially n-channel MOS devices which must operate in an ionizing radiation environment, it is desirable to produce Separation by IMplantation of OXygen (SIMOX) wafers which have a layer of poor quality silicon near the Si/buried SiO2 interface. At the same time, these wafers must have low defect, high quality silicon near the wafer surface for device fabrication.We have demonstrated that with Ge ion implantation and solid phase epitaxy regrowth, the surface region of the silicon top layer of the SIMOX wafer is improved and the region adjacent to the buried SiO2 is degraded. These results have been observed by RBS/channeling, XTEM, and plane view TEM.
Effects of Helium Ion Implantation on the Optical and Crystal Properties of GaAs
Authors: Bowman R. C. , Adams P. M. , Knudsen J. F. , Moss S. C. , Dafesh P. A. , Smith D. D. , Herman M. H. , Ward I. D. 
Published: March 2011

AbstractThe damage to GaAs crystals caused by helium ion implants has been monitored by changes in the Raman scattering phonon modes, double-crystal x-ray diffraction rocking curves, photoreflectance (PR), and electron beam electroreflectance (EBER) band edge transitions. As the implanted helium ion dose was increased, the various techniques revealed threshold damage behavior at very different levels. Although PR and EBER were the most sensitive to the defects created at the lowest ion doses, all techniques indicated substantial disorder for implants greater than 1014 ions/cm2.
Ion Implantation into Inp/InGaAs Heterostructures Grown by Movpe
Authors: Häussler Wulf , Walter J. W. , Müller J. 
Published: March 2011

AbstractAnnealing of Beryllium implantations into epitaxial InP/InGaAs hetero-structures was investigated. Different ion energies were used to position the profile maximum in the InP cap, at the hetero-interface, or in the underlying InGaAs layer. By measuring the Be atom and carrier profiles, it is shown that annealing conditions necessary for optimum Be activation in the InP cap layer are compatible with good profile control for Be in InGaAs. There is a slight transfer of Be across the interface during annealing, which is important, if the pn-juntion is intended to be close to the hetero-interface.
The Study of Boron Implantation in 1:7 Nd/Fe Multilayers
Authors: Cheng Guoan , Peng Yingguo 
Published: March 2011

AbstractThe structures and magnetic characteristics of multilayered samples with alternatively deposited metal layers (Nd and Fe) were studied for 80 keV boron ion implantation to various doses. Boron ion implantation induced amorphization in Nd/Fe multilayers gradually with increasing irradiation dose. The hysteresis loops of magnetization of the samples showed that a sunken curve appear-ed in the second and fourth quadrants of the loops for the depo-sited Nd/Fe films and disappeared when implantation dose was more than 4*1016 B+/cm2. During ion irradiation, the coercive forces of the films were decreased. The saturation magnetization and the residual magnetization decreared first and then increased with increasing ion dose, the squareness ratio S. R increased first and then decreased. Discussion was carried out in this paper.
The Ion Implanted Arsenic Tail in Silicon
Authors: Beck S. E. , Jaccodine R. J. , Clark C. 
Published: March 2011

AbstractRapid thermal annealed tail regions of shallow junction arsenic implants into silicon have been investigated. Tail profiles have been roduced by an anodic oxidation and stripping technique after implantation to fluences of 1014 to 1016 cm−2 and by implanting through a layer of silicon dioxide. Electrical activation and diffusion have been achieved by rapid thermal annealing in the temperature range of 800 to 1100 °C. Electrically active defects remain after annealing. Spreading resistance and deep level transient spectroscopy results are presented. The diffusion of the arsenic tail is discussed and compared with currently accepted models.
Impurity Gettering by Implanted Carbon in Silicon
Authors: Wong H. , Cheung N. W. , Yu K. M. , Chu P. K , Liu J. 
Published: March 2011

AbstractWe have observed strong gold gettering by implanted carbon in silicon. It was found that the gettering agents in carbon implanted layers are point defects associated with singular carbon atoms. The positions of the gettered Au atoms were found to be distorted substitutional sites. A pointdefect gettering model is proposed to explain our findings.
New Electronic Properties of Metal / III-V Compound Semiconductor Interfaces
Authors: Brillson L. J. , Viturro R. E. , Chang S. , Shaw J. L. , Mailhiot C. , Zanoni R. , Hwu Y. , Margaritondo G. , Kirchner P. , Woodall J. M. 
Published: March 2011

ABSTRACTRecent studies of interface states and band bending at metal / III-V compound semiconductor interfaces reveal that these junctions are much more controllable and predictable than commonly believed. Soft x-ray photoemission spectroscopy studies demonstrate a wide range of band bending for metals on many III-V compounds, including GaAs. Cathodoluminescence spectroscopy measurements show that discrete states form at the microscopic junction which can have a dominant effect on the band bending properties. Internal photoemission measurements confirm the bulk barrier heights inferred by photoemission methods. After separating out surface chemical and bulk crystal quality effects, one finds simple, predictive barrier height variations which follow classical Schottky behavior.
The Adsorption of Gallium on the Cleaved Surface of InP,InAs and InSb
Authors: Rodrigues W.N. , Mönch W. 
Published: March 2011

Studies of chemical trends may provide additional insights in complicated reactions between adsorbates and substrates. Here, the interaction of gallium with InP, InAs and InSb cleaved surfaces was investigated by using photoemission spectroscopy (UPS).Ga was evaporated from a Knudsen-type cell which was placed at a distance of approximately 15 cm in front of the surfaces cleaved in situ. After the evaporation rate, which was monitored by using a quartz oscillator, had stabilized the amount of Ga deposited was determined from the exposure time. The film thicknesses given in A are nominal values since Ga was found to exhibit island growth. The energy distribution curves (EDC-s) of the photoemitted electrons, which were excited by HeI and HeII radiation provided by a home-built discharge lamp, were recorded by using a single or a double-pass cylindrical mirror analyzer.
Correlations Between Electrical Properties and Solid-State Reactions in Co/N-GaAs Contacts: A Bulk and Thin-Film Study
Authors: Shiau F.-Y. , Chang Y. A. 
Published: March 2011

ABSTRACTA fundamental and comprehensive approach has been taken to study Co//GaAs interfacial reactions, using phase diagram determination, bulk and thin-film diffusion couple studies, and electrical characterization. Phase formation sequences and interfacial morphologies are found to be similar in bulk and thin-film couples. Thermodynamic and kinetic analyses are used to rationalize the contact formations. The electrical properties of the contacts are correlated to the phase formation sequences and phase diagram information.
Experimental and Theoretical Analysis of Strain Relaxation in GexSi1-x/Si(100) Heteroepitaxy
Authors: Hull R. , Bean J.C. 
Published: March 2011

ABSTRACTBy analyzing in-situ strain relaxation measurements of GexSi1-x/Si(100) epitaxy in a Transmission Electron Microscope, we are able to quantify the fundamental parameters which describe strain energy relaxation via misfit dislocation introduction. Quantitative descriptions of misfit dislocation nucleation, propagation and interaction processes are derived. The numerical parameters obtained from these experiments are then incorporated into a predictive theoretical model of strain relaxation whichrelies only upon experimentally measured quantities. Good agreement between experiment and theory is obtained over a wide range of data.
Electron-Beam-Induced-Current (EBIC) Imaging of Defects in Si1−xGeX Multilayer Structures
Authors: Sturm J.C. , Xiao X. , Garone P.M. , Schwartz P.V. 
Published: March 2011

ABSTRACTThe electron-beam-induced-current (EBIC) technique has been used to image dislocations and other defects at strained Si: Sil−xGex epitaxial interfaces and in overlying epitaxial layers grown by Limited Reaction Processing. Depending upon the bias conditions and test structure, one can distinguish between interface defects and those in overlying films. We have found that for a low density of misfit dislocations, a high quality (defect-free) overlying epitaxial layer can be grown, but for a high density of dislocations certain line defects propagate upwards in the overlying layers.