bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of RTA To Bipolar Ic'S
Authors: Reuss Robert H. , Bushey Thomas P. 
Published: March 2011

ABSTRACTRTA has been investigated for a variety of applications including implant anneal and modification of poly silicon. However, little has been reported on the integration of RTA into actual process flows. We describe here results for bipolar IC's with RTA for the fabrication of shallower junctions and lower sheet resistance (Rs) poly electrodes. For a successful bipolar IC, not only are good diode characteristics and related transistor parameters important, but also, resistor behavior, uniformity, and yield are critical. An AG Heatpulse system was used to successfully anneal the emitter implant of 2.0 um design rule bipolar IC's. The yield and variation in gate delay were comparable to furnace annealed counterparts. These results are especially encouraging since both transistor performance and resistor matching are critical for the circuits tested. However, significant improvement in gate delay was not observed.
Control of Bipolar Junction Transistor Current Grain Using Rapid Thermal Processing.
Authors: Kermani A. , Van Gieson F. , Litwin S. , Sullivan R. , DeBolske T. J. , Crowley J.L. 
Published: March 2011

ABSTRACTThe activation of ion implanted emitters for two types of NPN bipolar junction transistors ( BJT ) by rapid thermal processing (RTP) was evaluated. The dopant profiles and the resultant junction depths were measured for various thermal cycles, using spreading resistance profile technique. The electrical characteristics of the transistors were then determined and compared to the standard furnace processes. The common emitter current gain values, hFE, for arsenic emitters were low and phosphorous emitters exhibited improved or comparable betas. The breakdown voltages in common emitter configuration, BV,CEO, BVcEs and BVEBO were comparable or better than the furnace annealed samples and no evidence of transistor leakage was observed.
The Effect of Rapid Thermal Processing on the Electrical Characteristics of Polysilicon Gate Mos Capacitors
Authors: Felch Susan B. , Hodul David T. , Mak Salimian Mak Salimian 
Published: March 2011

ABSTRACTRapid thermal processing has previously been observed to affect the dielectric integrity of thin oxides.' In order to study this phenomenon in more detail, we have fabricated a set of wafers with 290 Å thick gate oxide and patterned pads of 2000 Å thick doped polysilicon. Some of the pads were patterned with a wet etch, while others were dry etched in a commercial reactive ion etcher (RIE), which is suspected to be a damaging process. To simulate a self-aligned MOS process, some of the patterned wafers were also ion implanted with 70 keV, 2E15 As+/cm2 . Subsequently, all of the wafers were rapidly annealed in a Varian RTP-800 lamp annealer under a variety of conditions (lO00-1100°C, 10-30 sec), and the breakdown characteristics of the MOS capacitors were measured. A few control samples were annealed in a furnace. It was found that the rapid annealing cycle without ion implantation or dry etching caused no deterioration of the oxide quality. However, rapid annealing after either RIE or implantation does result in oxide breakdowns at lower voltages, with those capacitors having higher perimeter-toarea ratios affected to a greater degree. The effect of capacitor shape and annealing conditions on breakdown statistics and uniformity will be presented and discussed in light of possible ion bombardment damage during RIE and oxide charging during ion implantation. Several mechanisms explaining the breakdown properties will be discussed.
Silicon Temperature and Thermal Gradients Measurements in a Rapid Thermal Processor Operating at Atmospheric Pressure or in Vacuum
Authors: Dilhac J-M. , Ganibal C. , Martinez A. 
Published: March 2011

ABSTRACTTemperature-time profiles obtained by an optical pyrometer and a mechanically contacted thermocouple are first presented it appears that the thermocouple response is sensitive to the pressure in the processing chamber. The authors suggest that, in vacuum, the thermocouple is thermally isolated from the wafer, until the temperature is high enough for thermal radiation exchanges to occur. Experimental evidence of the influence of thermal history, and of gas pressure and flow, on temperature drop at periphery of the wafer is then given.
A Method for Rapid Thermal Annealing of Compound Semiconductors by Cw CO2 Laser Irradiation
Authors: Neta U. , Richter V. , Kalish R. 
Published: March 2011

ABSTRACTA new Rapid Thermal Processing technique based on heating by irradiation from CO2 laser is presented. It is particularly suitable for thermal treatment of low melting temperature materials such as annealing implantation induced damage in compound semiconductors.Short time heating of the sample is achieved by its contact with a quartz plate heated by photons from a CW CO2 laser. The quartz serves both as an absorbing medium for the radiation and as a proximity cap. Steady state temperature can be obtained by the simultaneous heating of the sample by the laser and its cooling by a jet of N2 gas.The present technique, when applied to ion implanted InSb (TA<450°C, t=10 seconds), leads to removal of the implantation damage which is comparable to that obtained by furnace or flash lamp (Heatpulse™)annealing.
Rapid Thermal Processing: How Well is it Doing and Where is it Going?
Authors: Sedgwick T.O. 
Published: March 2011

ABSTRACTThe use of Rapid Thermal Processing (RTP) as a processing tool in semiconductor technology is still increasing and and becoming more diverse. The use of RTP in a reactive mode for film growth and deposition is an important new direction. The strong interest in III-V compound annealing studies represents one of the most important application areas. Although RTP is predominantly exploratory and developmental in nature it is slowly being introduced into the manufacture of Si devices. The technological necessity for the greater use of RTP in routine production will depend on either demonstrated productivity/cost advantages or on some intrinsic advantage of RTP. The intrinsic advantages of RTP are due to the single wafer processing nature of the operation or due to the possibility of selectively enhancing one desired process over another undesired reaction in a partically fabricated structure. Although significant impovements in commercially available reactors have been made in the last several years, better temperature measurement and control and particularly temperature uniformity of the wafer are still sorely needed.
Properties of Gallium Implanted Furnace and Rapidly Annealed Polycrystalline Silicon
Authors: Harrison H.B. , Pogany A.P. , Komem Y. 
Published: March 2011

ABSTRACTPolycrystalline silicon films have been amorphized by implantation with 100keV Ga ions of doses 0.3 and 6×1015cm−2. These films were subsequently recrystallized using either a furnace for longer times lower temperature (∼30 mins, 600° C) or rapid thermal processing (RTP) for shorter times higher temperatures ( ≤ 30 sec, 800° C, 900° C) in an endeavour to suppress any long range movement of the Ga during the anneal phase. It is found that for both the furnace and RTP for temperatures ≤ 800°C no significant movement is observed and that the lower temperature anneal for the highest dose produces the highest electrical conductivity. By contrast however, annealing at 900° C, even though the initial conductivity is higher than for any other anneal we observe a significant reduction with time and extremely rapid movement of the dopant species throughout the original poly layer. An initial rationale for this behaviour is proposed in terms of a liquid phase transformation during annealing.
Secondary Grain Growth During Rapid Thermal Annealing of Doped Polysilicon Films
Authors: Cammarata R. C. , Thompson C. V. , Garrison S. M. 
Published: March 2011

ABSTRACTRecently there has been a great deal of interest in the use of thin (≤0.1µm) heavily doped polysilicon films as diffusion sources for shallow junctions in silicon substrates. It has been reported that grain growth and solid phase epitaxy occur during annealing of such films and that the apparent rates of both are much greater during rapid thermal annealing. We report similar grain growth behavior for rapid thermal annealed thin polysilicon films deposited onto amorphous SiO2. Based on these experimental results we propose that solid phase homoepitaxy in polysilicon films occurs via secondary grain growth. This process proceeds rapidly at first but slows down due to grain boundary drag. Rapid thermal annealing of polysilicon films provides a method for selectively utilizing the kinetic process that dominates for short times.
Electrical Properties of n- and p-type In0.53Ga0.47As Layers Formed by Ion Implantation and Rapid Thermal(Flash)Anneal
Authors: Liu S.G. , Narayan S.Y. , Magee C.W. , Wu C.P. , Kolondra F. , Paczkowski J. , Capewell D. 
Published: March 2011

ABSTRACTRapid thermal annealing (4−7s) of 28Si and 9Be implants in VPE-grown In0.53Ga0.47As has produced n- and p-type active layers with controlled doping levels between 1017 and 3×1018 cm−3. The multiple-implant schedules were based on Rp and ΔR data derived from SIMS measurements on single-energy implants. The activated n- and p-type layers have a good surface morphology and 300 K mobilities of 3000–7000 and 100–200 cm2 /V−s, respectively. Data on implant schedules, electrical characteristics, carrier concentration profiles, and Rp /ΔRp information are presented.
Thermal Stability of Tasix-Gaas Schottky Barriers
Authors: Haynes T. E. , Han C. C. , Lau S. S. , Picraux S. T. , Chu W. K. 
Published: March 2011

ABSTRACTSputtered TaSix films on GaAs have been examined as potential refractory Schottky barrier contacts suitable for self-aligned gate fabrication of GaAs MESFETs. The thermal stability of electrical and physical characteristics has been studied following furnace annealing or rapid thermal processing of contacts with compositions near Ta5Si3 (x=06). The electrical characteristics, interface interdiffusion, and evaporation loss of Ga and As through the contact have been examined. The barrier heights of 30-min furnaceannealed contacts were found to increase with temperature over the range 600 to 900°C. The Schottky barrier heights after rapid thermal processing (RTP) of the contacts were fixed at 0.78 eV for temperatures in the range 700 to 900°C. A major finding of this work is that the Schottky barrier contact maintains its integrity even though the equivalent of at least 5 monolayers of Ga and As have decomposed and evaporated through the contact.
Rapid Thermal Processing for High-Speed III-V Compound Devices
Authors: Kuzuhara M. 
Published: March 2011

ABSTRACTRecent activities in rapid thermal processing on III-V compound materials are reviewed with primary focus on its application to high-speed GaAs integrated circuits. Advantages of the rapid thermal processing are discussed, from the viewpoint of doping characteristics obtained both for n-type channel implants and for high dose n-type contact implants. Enhanced electrical activation is demonstrated by optimizing the encapsulating material employed for annealing high-dose Si implants. Not only these advantages, but also several problems, which should be solved before this technology can be fully utilized in industrial applications, are discussed. Special attention is devoted to improvement in the activation uniformity over a complete 2 inch diameter GaAs wafer.
The Redistribution of Impurities Under RTP for Polysilicon Capped Silicon
Authors: Hockett R. S. 
Published: March 2011

ABSTRACTRapid Thermal Processing is being evaluated in the IC industry as a way to meet the thermal budget requirements of reduced scaling in high performance Si IC's. As scaling is reduced and alternative processing is used, the study of low level interfacial impurities is expected to become more important. An example is presented here for the redistribution of interfacial impurities under RTP for polysilicon capped silicon similar to that proposed for shallow junction bipolar transistors.
Co-Implantation of Si And Be in GaAs by Rapid Thermal Annealing
Authors: Yu Tan-Hua , Wang Sujane 
Published: March 2011

ABSTRACTA buried p-layer in GaAs MESFET channel is successfully formed by (Si,Be) co-implantation and rapid thermal annealing process. The annealing cycle is optimized to activate Si and Be simultaneously and to minimize the dopant redistribution for precise dopant control. As a result, more than 80% activation efficiency for both Si and Be, as well as the greatly improved doping abruptness from 85 nm/decade to 65 nm/decade are achieved. Devices are fabricated and superior performance including sharper pinchoff, an increase of RF gain by 2–3dB and a 40% decrease in backgating effect is observed.
A Two Step Rapid Thermal Annealing Process for Be Implant Activation in GaAs
Authors: Plumton D.L. , Duncan W.M. , Tran L.T. 
Published: March 2011

SUMMARY ABSTRACTA two step rapid thermal anneal (RTA) has been studied for activating Be implanted GaAs, where a short duration, high temperature step is used to electrically activate the Be followed by a longer, low temperature anneal for lattice regrowth. p-n diodes show a substantial reduction in reverse diode leakage current after the low temperature second step anneal, when compared to a single step RTA or to furnace annealing (FA). For low energy Be implants, no difference in elecrical activiation between the two step anneal is observed. Raman studies demonstrate that residual substrate impurities and high Be concentrations inhibit restoration of single crystal lattice characteristics after RTA. Lattice quality is shown not to limit diode characteristics in the RTA material.
Rapid Thermal Annealing of Low Temperature Silicon Dioxide Films
Authors: Fitch J.T. , Lucovsky G. 
Published: March 2011

ABSTRACTThis paper discusses the local atomic structure in silicon dioxide films formed by the oxidation of silicon in dry oxygen in a temperature range between 850 and 1150°C. The films grown at 850°C were subjected to rapid thermal annealing (RTA)at temperatures between 800 and 1200°C and for periods of time ranging from 1 to 100 seconds. The local atomic structure has been studied via infrared (IR) spectroscopy and ellipsometry. We discuss the temperature dependence (with respect to both oxidation temperature, and annealing temperature [and time]) of the frequency, v, and linewidth, δv, of the Si-O-Si bond stretching vibration, and the index of refraction, n, at 632.8 nm. We make comparisons with silicon dioxidefilms deposited by remote plasma enhanced chemical vapor deposition (RPECVD) at temperatures between 100 and 400C and subjected to high temperature annealing (850 to 1050°C). We find that the variations in v, δv and n with growth, deposition and annealing can be understood in terms of systematic variations in the magnitude of the bond angle, 2e, at the oxygen atom bonding sites.
Oxygen Precipitation Along Individual Ion Tracks During High Dose O+ Implantation into Silicon
Authors: Maszara Witold P. 
Published: March 2011

ABSTRACTSilicon wafers with and without protective1Ahermil oxide were implanted with oxygen at 150keV with doses 1.6 – 2.0×1018 cm−2. Transmission electron microscopy (TEM) and secondary ion mass spectroscopy (SIMS) were used to study the top silicon layer remaining above the implanted buried oxide. regular array of spheroidal voids filled with oxygen gas was observed only in the samples that were not protected by the oxide. The voids were aligned into individual columns whose crystallographic orientation with respect to the host silicon lattice matched the direction of the implantation. The origin and the kinetics of their formation are discussed.
Channeling Studies of Ion-Implantation Damage in Titanium Dioxide
Authors: Stoffel N. G. , Hart D. L. 
Published: March 2011

ABSTRACTRutherford backscattering in the channeling alignment was used to characterize the damage produced in rutile TiO2 by oxygen ion implantation at energies of 200 and 400 keV. Backscattering g{om the dajnaged layer increases sublinearly with ion dose above 4×1015 ions/cm2. Complete amorphization was not achieved even for much higher doses and implant temperatures well below room temperature, and remnants of the original crystal lattice remain in the damaged layer. Substantial defect annealing occurs at 450 C, and essentially complete lattice recovery is observed at 750 C when the annealing takes place in a reducing environment. In an oxidizing ambient, higher annealing temperatures are required to achieve the same degree of crystal regrowth, and dechanneling actually increases at lower annealing temperatures, apparently due to the coalescence of point defects into extended defects. The optical properties of the implanted layer were also probed by ellipsometry.
Ion Induced Mixing of AlGaAs/GaAs Superlattices
Authors: Venkatesan T. , Schwarz S. A. , Mei P. , Yoon H. W. 
Published: March 2011

ABSTRACTSubsequent to the implantation of certain ions, the thermal stability of AlGaAs/GaAs superlattices can be reduced, enabling mixing of the layers at temperatures where they would otherwise be stable. The mixed layers have intermediate alloy composition and are of good crystalline quality. As a result this process is of great value in device fabrication where a high degree of vertical and lateral bandgap control is desirable. This paper reviews our work in understanding the mechanism of diffusion, its dependence on varilous process parameters, and potential applications in device fabrication.
Mechanism of Interdiffusion in Hg1-XXxTe/CdTe Superlattices (X = Cd, Mn, AND Zn)
Authors: Staudenmann J.-L. , Knox R. D. , Faurie J.-P. 
Published: March 2011

ABSTRACTThe interdiffusion mechanism in Hg(l-x)X(x)Te/CdTe superlattices where X is Cd, Mn, or Zn can be deduced from the magnitude of the interdiffusion activation energy. By comparing in-situ x-ray diffraction measurements (our work) with results from Tang and Stevenson (J. Vac. Sci. Technol. AS, 1987), it is found that anionic and cationic Frenkel pairs represent the most likely interdiffusion mechanism in Hg(l-x)X(x)Te/CdTe superlattices. This model mixes vacancies and interstitials, as well as maintaining the conduction type and the electronic mobility. It is further shown that interdiffusion sets in as soon as the growth starts.
The Influence of Dose Rate on the Formation of CrSi2 by Ion Mixing
Authors: Kim S.-J. , Jamieson D. N. , Nicolet M-A. , Averback R. S. 
Published: March 2011

ABSTRACTThe relationship between growth rate of CrSi2 and dose rate during Xe ion irradiation at 500K is investigated. Dose raies difffering by up to a factor of 40 have been utilized to study the relationship. For a fixed total dose, a lower dose rate results in a thicker silicide layer compound to a higher dose rate. The results are explained from radiation-enhanced diffusion theory.
Control of Al Orientation on Si(100) Substrate Using a Partially Ionized Beam
Authors: Choi C.-H. , Ramanarayanan R. , Mei S.-N. , Lu T.-M. 
Published: March 2011

ABSTRACTWe report an investigation of Al films deposited on Si(100) surfaces by a partially ionized beam. By controlling the Al ion to atom ratio in the beam and the bias potential applied to the substrate, two different orientations, namely, the Al(110) and the Al(111) faces, can be formed on the Si(100) substrate.
Properties and Effects of Laser-Induced Plasma During Evaporative Deposition of Thin Films
Authors: Sankur H. , Denatale J. , Gunning W. J. 
Published: March 2011

ABSTRACTThe properties of plasmas generated by the interaction of a pulsed CO2 laser with several solid evaporation targets were studied and the films deposited from such plasmas were characterized. A large flux (˜ 1014/cm2/s) of ions at high velocities (2 − 10 × 106 cm/s) was measured in these plasmas. ZrO2 thin films deposited by laser-assisted evaporation on room temperature substrates had crystalline-oriented structures. Low optical absorption and high refractive index values (2.15 at 632.8 nm) indicated the stoichiometric and dense nature of these films.
Preparation of Aluminum Nitride and Oxynitride Thin Films by Ion-Assisted Deposition
Authors: Targove J. D. , Lingg L J. , Lehan J. P. , Hwangbo C. K. , Macleod H. A. , Leavitt J. A. , Mcintyre L. C. 
Published: March 2011

ABSTRACTAluminum nitride thin films have been deposited by ion-assisted deposition. Aluminum was electron-beam evaporated onto substrates with simultaneous nitrogen ion bombardment. Rutherford backscattering spectrometry showed that nitrogen-to-aluminum ratios of one or greater could be achieved with sufficient nitrogen ion fluxes. This excess nitrogen apparently degrades the optical properties of the films in the visible. Annealing at 500°C improves the optical properties drastically at the expense of a slight oxygen diffusion into the films. Finally, aluminum oxynitride films were deposited by adding an oxygen backfill to the vacuum chamber during deposition. These films had very similar optical properties to the annealed nitride films.
A Study of Boron Implanted Silicon
Authors: Chang P.-H. , Liu H.-Y. , Anthony J. M. 
Published: March 2011

ABSTRACTSingle crystal <100> Silicon wafers implanted by 1×1016/cm2 boron ions at 30, 80, or 130 KeV are studied. The through thickness strain distribution in the wafer is found to reverse from tension in the as-implanted condition to compression after annealing for 20 minutes at 900°C. The 30 KeV implant generates a partially amorphized region under the wafer surface. Boron diffuses out of this region and accumulates at greater depth during annealing. Higher energy implants do not generate such an amorphous region and many long rod-like defects develop under a band of dislocation loops during annealing. Enhanced boron diffusion was observed at the tail of the boron profile at all three energies.
Limits on the Accuracy of Stoichiometry Determined by Rutherford Backscattering Using Computer Peak Fitting.
Authors: Mcintyre L. C. , Ashbaugh M. D. , Leavitt J. A. 
Published: March 2011

ABSTRACTRutherford Backscattering Spectrometry (RBS) using MeV ions is capable of routinely measuring absolute atomic areal densities to an accuracy of about 3% and relative areal densities to a fraction of 1% if the elastic scattering peaks from different elements do not overlap. The accuracy of areal density measurements can be seriously reduced in cases where the sample thickness is large enough to cause overlapping peaks. We report here an investigation of the use of standard computer fitting techniques to analyze overlapping peaks in elastic scattering spectra and its effect on the accuracy of the final results of an RBS analysis.