bluuebunny/crossref_metadata_2025_split huggingface dataset:
Low Pressure Growth of GaAs/AlGaAs Layers on 2N and 3N Substrates in a Multiwafer Reactor
Authors: Heyen M. , Heuken M. , Strauch G. , Schmitz D. , Jurgensen H. , Heime K. 
Published: March 2011

AbstractThe epitaxial growth of GaAs/AIGaAs layers and multilayer structures has been investigated in different low pressure horizontal multiwafer reactors for high throughput capable to handle several 2“ and 3“ wafers in one run. The growth behavior in these reactors will be described with respect to gas flow dynamics. The background carrier concentration is in the 1014 cm−3range. The uptake of dopants (SiH4) is strongly reduced upon pressure reduction.The uniformity of GaAs and AIGaAs layer thickness is better than ±3 % over 3“ diameter substrates. The uniformity of composition (measurer on HEMT structures) is better than ± 1 % across 98 % of the wafer areas (± 0.5 % across 75 %). Also the reproducibility is better than 1 %. Results on the uniformity of dopant distribution will also be presented.HEMT structures grown at low pressure conditions show mobilities of 100,000 cm2/Vs at 77 K and over 210,000 cm2/Vs at 20 K (ns= 6×1011 cm−2, spacer thickness 9 nm). HEMT devices with transconductance of 330 mS/mm could be achieved.
Vacuum Chemical Epitaxy: High Throughput GaAs Epitaxy Without Arsine
Authors: Fraas L. M. , Girard G. R. , Sundaram V. S. , Master Chris , Stall Rick 
Published: March 2011

AbstractMetal organic chemical vapor deposition (MOCVD) and molecular beam epitaxy (MBE) are well established methods for growing epitaxial GaAs and AlGaAs films. However, MOCVD equip- ment uses the highly toxic gas, arsine, and MBE equipment is very costly and coats only one wafer at a time. We have developed a vacuum chemical epitaxy (VCE) reactor which avoids the use of arsine and allows multiple wafers to be coated in a production environment.
The Growth, Characterization and Electronic Device Applications of GaAs/Si
Authors: Jordan A. S. , Pearton S. J. , Hobson W. S. 
Published: March 2011

AbstractWe review the growth of GaAs on Si by MO-CVD and MBE and discuss the relative merits of these techniques. Major emphasis is placed on the structural and optical characterization of the material that may be indicative of device performance. Typical GaAs layers on Si are free of anti- phase domains and the crystallinity at the surface for a 3-4μm thick deposit approaches that of bulk GaAs, as evidenced by the RBS backscattering yields and Si ion implantation profiles. The major drawbacks of GaAs heteroepitaxy on Si are the very large dislocation densities (106- 109cm−2), the relatively high unintentional doping concentration (>5 × 1014cm−3) that is partly attributable to Si outdiffusion, and the excessive bowing due to thermal expansion coefficient mismatch. While there are growth and processing techniques to overcome bowing or at least its influence, dislocations and low resistivity are hard to remedy. We discuss novel schemes to reduce dislocations (selective area growth, superlattices and thermal cycling) and efforts to improve the electrical properties (doping, optimization of V/III ratio). A variety of electronic devices and circuits have been fabricated using GaAs/Si. We shall present results on MESFETs, HBTs and HFETs processed in our laboratory and elsewhere. It is quite encouraging that HFETs with a transconductance of 220mS/mm are achievable. However, lasers in room temperature CW operation still have a very limited lifetime. Finally, we discuss the implications of GaAs/Si for a broader area of mismatched heteroepitaxy (InP/Si, InP/GaAs, etc.) and speculate on the future prospects for this new materials technology.
Improvement of Minority-Carrier Properties of GaAs on Si
Authors: Vernon S.M. , Ahrenkiel R.K. , Al-Jassim M.M. , Dixon T.M. , Jones K.M. , Tobin S.P. , Karam N.H. 
Published: March 2011

AbstractGaAs-on-Si structures have been grown by atmospheric-pressure metalorganic chemical vapor deposition (MOCVD); in some samples, the GaAs nucleation layer was deposited by atomic layer epitaxy (ALE). Material quality has been characterized by Nomarski microscopy, time-resolved photoluminescence, trans- mission electron microscopy, and the performance of photovoltaic devices. The minority-carrier lifetime has been correlated with defect density and growth parameters. The use of a thermal-cycle-growth technique is seen to be a major factor in improving GaAs-on-Si material quality without resorting to the use of thick buffer layers.
Electronic Transport Properties of ZnSe Layers on GaAs
Authors: Marshall T. , Colak S. , Houten H. Van , Petruzzello J. , Greenberg B. , Cammack D. 
Published: March 2011

AbstractThe electronic transport properties of ZnSe layers grown by MBE on GaAs sub- strates are studied by small-signal ac admittance, dc current-voltage, and Hall effect measurements. This work is supplemented by a study of TEM and x-ray rocking curve data. We find that the transport characteristics are strongly affected by the proper- ties of the ZnSe/GaAs interface. From the dc and ac measurements, we determine the total barrier height at the interface of thick (1-6 µm) ZnSe layers on n+-GaAs, and find that it is in general voltage dependent. While some samples are found to have a very high peak mobility (> 10,000cm2 /Vsec), an anomalous reduction in the mobility in a large fraction of the samples is found, and attributed to the presence of non- uniform space charge regions.
Mocvd Growth of CdTe and HgTe on GaAs in a Vertical, High-Speed, Rotating-Disc Reactor
Authors: Tompa G.S. , Nelson C.R. , Reinert P.D. , Saracino M.A. , Terrill L.A. , Colter P.C. 
Published: March 2011

AbstractThe metalorganic chemical vapor deposition (MOCVD) growth of CdTe and HgTe on GaAs (111) and (100) substrates in a vertical, high-speed, rotating-disc reactor was investigated. A range of total reactor pressure, carrier gas flow rate, chemical concentrations, deposition temperature, and rotation rate have been investigated in an attempt to optimize growth conditions. Diisopropyltelluride (DIPTe) and Dimethylcadmium (DMCd) were used as growth precursors. Thickness uniformity varies less than +/- 1.5% over 50 mm diameter wafers. Films having FWHM X-ray rocking curves less than 90 arcsec were obtained on GaAs (111) substrates. The films have excellent surface morphology, exhibiting less than 5x104 cm-2 orange peel dents which are << 1 µm in size. An elemental mercury source was added to the growth system. Initial results for the growth of HgTe and HgCdTe will be discussed in this text.
InGaAs Compositional Control in a Halide-Based Vapor Levitation Epitaxy System
Authors: Yee Camellia M. L. , Davisson Pamela S. 
Published: March 2011

AbstractThe Vapor Levitation Epitaxy (VLE) system utilizes quartz frits directly in front of the growth surface of the substrate. This impacts on both epitaxial layer thickness uniformity and compositional uniformity. The highly uniform layers achievable with the process have been described.In this paper we discuss the compositional uniformity of InGaAs epitaxial layers grown by the VLE process. The composition of the InGaAs is shown to vary with time during a growth run and across the wafer when using the same growth conditions as for an open tube halide system. This compositional variation occurs for InGaAs layers exceeding 1.5 μm in thickness. We show that with the proper gas phase composition, InGaAs epitaxial layers in excess of 5.0 μm thick can be grown with excellent compositional uniformity.
Kinetic Limits to Growth on GaAs by Omcvd
Authors: Aspnes D. E. , Bhat R. , Colas E. , Koza M. A. , Keramidas V. G. , Studna A. A. 
Published: March 2011

AbstractUsing a real-time surface probe with 0.01 monolayer (ML) sensitivity, we determine the rate-limiting steps for atmospheric-pressure, alternating-layer-epitaxy OMCVD growth on (001) and (110) GaAs with trimethylgallium and arsine sources. The reaction of TMG with AsH3- saturated (001) GaAs is limited by a competition between decomposition (at 39 kcal/mole) and desorption of TMG chemisorbed (at −26 kcal/mole) via an excluded-volume mechanism. The reaction of AsH3with TMG-saturated (001) GaAs shows an initial fast transient followed by a slower recovery. On (110) GaAs, TMG reacts essentially instantaneously with an AsH3-saturated surface while the reaction of AsH3 with a TMG-saturated surface is relatively slow. In the latter case temperature and pressure dependences indicate a fast AsH3 -surface reaction that is blocked by an adsorbed species that must be desorbed before the AsH3 -surface reaction can take place.
Silicon Carbide Structures Prepared by Rapid Thermal Chemical Vapor Deposition
Authors: Crowley J.L. , Liao J.C. , Kleins P.H. , Campisi G.J. 
Published: March 2011

ABSTRACTThe deposition of beta Silicon Carbide unto single crystal silicon (100) wafers using rapid thermal chemical vapor deposition (RTCVD) has been carried out using silane and ethylene as the source gases. Deposition temperatures were varid from 1100°C to 1300°C. Auger analysis revealed the silicon carbide films to be stoichiometric at all temperatures. Infrared spectroscopy data taken between 1200 cm−1 and 60° Cm−1 show the appearance of the longitudinal optical phonon at 974 cm−1 and the transverse optical phonon at 794 cm−1 in samples deposited at 1200°C and above. Stress in the films deposited on the single crystal silicon substrates is seen to go from zero or slightly compressive at 11O0°C to strongly tensile at 1300°C.
GexSil-x Layers Grown by Rapid Thermal Processing Chemical Vapor Deposition
Authors: Jung K. H. , Kim Y. M. , Chun H. G. , Kwong D. L. , Rabenberg L. 
Published: March 2011

ABSTRACTRapid thermal processing chemical vapor deposition was used to grow single and multilaye repitaxial GexSil-x/Si structures on (100)Si substrates using GeH4 and SiH2Cl2 at 900°C and 1000°C with SiH2Cl2:GeH4 ratios of 14:1 to 95:1 at 5 Torr. Misfit dislocation free layers with few threading dislocations were grown for Ge concentrations of up to 13%. Misfit dislocation networks aligned along <110> were formed at the interface of films with higher Ge concentrations. Dislocation loops were also found at the interface. GexSil-x layers grown at 1000°C were highly crystalline, but relaxed. In multi-layer structures, AES depth profiles showed Ge pile-up at the GexSi1-x/Si interface of layers with higher Ge concentrations.
Tungsten Film Formation on Silicon by Combining Ionic Decomposition of Metal Halides with Rapid Thermal Processing
Authors: Tidemand-Petersson Peer , SØRensen Gunnar 
Published: March 2011

ABSTRACTThin films of tungsten metal and tungsten silicide were formed by combination of spin-on of tungsten chloride dissolved in a volatile organic solvent, decomposition of the chloride by ion bombardment and finally heating in a new versatile Rapid Thermal Processing (RTP) system. The films resulting from this treatment were characterized by Rutherford Backscattering Spectrometry (RBS) prior to and after the ionic decomposition and heat treatment. The procedure and the results of the analysis are described and discussed in terms of process conditions in this paper.
Thermal Stability in the <Si>/TiSi2/TiN/Al Metallization System
Authors: Hamdi A.H. , Alvi N.S. , Kermani A. , Al-Kaisi M. 
Published: March 2011

ABSTRACTStability in the temperature range between 450°C and 525°C of reactively sputter deposited TiN and TiN formed simultaneously with TiSi2 using transient annealing has been investigated in the <Si>/TiSi2/TiN/Al metallization system.
Low-Temperature Self Aligned TiSi2'TiN Bilayer by Rapid Thermal Nitridation of Metastable Titanium Silicide in NH3 Ambient
Authors: Kermani Ahmad , Kuehne John 
Published: March 2011

ABSTRACTRapid thermal nitridation (RTN) of metastable Ti silicide in pure ammonia ambient has been shown to result in the formation of a bilayer TiSi 2'TiN structure. This bilayer structure provides an effective self-aligned diffusion barrier against aluminum spiking. Further, the simultaneous formation of TiN on top of the TiSi2 preserves the low resistivity of the silicide layer upon subsequent high temperature process steps. Rutherford backscatttering spectroscopy, Auger electron spectroscopy and four point probe techniques were used to analyze the stoichiometry of the nitrided layer, and to study the kinetics of the nitridation reaction. The nitridation of the metastable silicide film is a substitutional eaction which begins at the surface of the silicide and progresses by substituting nitrogen atoms for silicon. The nitrogen atoms result from dissociation of ammonia The released silicon atoms then diffuse to the silicide'silicon interface and deposit in an epitaxial manner. The benefits of the proposed metallization scheme are substantiated by electrical characterization of the bilayer structure in comparison with a conventional process.
High-Quality Gate-Oxide Films for Low-Temperature Fabricated Poly-Si TFTs
Authors: Suyama Shiro , Okamoto Akio , Shirai Seiiti , Serikawa Tadashi 
Published: March 2011

ABSTRACTHigh-quality gate-oxide films for poly-Si TFTs (Thin Film Transistors) are successfully produced by oxygen-argon sputter deposition at a low temperature (200°C). Silicon-oxide films that are sputter-deposited in an oxygen-argon mixture has higher resistivity and breakdown field than films that are sputterdeposited only in argon and thermal oxides grown on poly-Si. Moreover, TFT field-effect mobilities are considerably improved by mixing oxygen into the sputtering gas, resulting in 350 cm2 /V.sec. Subthreshold slope and threshold voltage are also reduced to 5.5 V and 0.8 V/decade. A temperature-dependence measurement of the drain current shows that these improvements in TFT characteristics result from a lowering of the barrier height at the poly-Si grain boundaries, indicating a reduction in the trap density at these boundaries. Results confirm the usefulness of gate-oxide films that are sputter-deposited in an oxygen-argon mixture, for lowtemperature fabricated poly-Si TFTs.
Performance and Reliability of Ultrathin Oxynitride Gate Dielectrics Prepared using In-Situ Multiple Rapid Thermal Processing
Authors: Lo G. Q. , Shih D. K. , Ting W. , Kwong D. L. 
Published: March 2011

ABSTRACTThe electrical characteristics of ultrathin oxynitride gate dielectrics prepared by in-situ multiple rapid thermal processing in reactive ambients (O2 and NH3) have been studied. Specifically, the conduction mechanism, charge trapping properties, time-dependent breakdown, and interface hardness in oxynitride films have been characterized as a function of both RTO and RTN processing parameters. In addition, N-channel MOSFET's have been fabricated using oxynitrides as gate dielectrics and their hot carier immunity has been examined and compared with devices with pure thermal oxides. Devices with superior electrical characteristics and reliability have been produced by optimizing RTO/RTN parameters.
Characterization of LPCVD of Silicon Nitride in a Rapid Thermal Processor
Authors: Johnson F. Scott , Miller Roderick M. , Öztüirk Mehmet C. , Wortman Jimmie J. 
Published: March 2011

ABSTRACTLow pressure chemical vapor deposition of silicon nitride has been studied using a cold-walled, lamp heated, rapid thermal processor. Films were deposited at low presure using both silane and dichlorosilane, diluted in hydrogen and argon carrier gasses. The dichlorosilane and ammonia reaction was found to be unsuitable for use in the cold-walled system. Rapid thermal chemical vapor depositions using silane and ammonia did not result in “bullseye” non-uniformities reported for low presure depositions in conventional hot-walled tube furnaces. Ammonia to silane ratios of 120:1 were found to result in stoichiometric silicon nitride films. Deposition rates are well suited for dielectricapplications. Electrical characteristics are comparable to those of films deposited using APCVD and LPCVD methods.
Long-Range Diffusion of Transition Metals in Silicon During Rapid Thermal Annealing
Authors: Sparks D.R. , Alvi N.S. , Sanders K. 
Published: March 2011

ABSTRACTA detailed comparison between transition metal diffusion results in silicon during rapid thermal annealing obtained in this and other studies with the diffusivity and solubility results obtained in the literature has been made. Using secondary ion mass spectroscopy, U-shaped diffusion profiles, possibly denoting amphoteric diffusion, have been noted fo Cu, Ni, and Pd in silicon during short anneals. Applications are reviewed.
Growth and Doping Kinetics of GexSil-x Structures by Limited Reaction Processing
Authors: Garone P.M. , Sturm J.C. , Schwartz P.V. , Schwarz S.A. , Wilkens B. 
Published: March 2011

ABSTRACTWe have investigated the growth rate and boron doping of Sil-xGex epitaxial films grown by Limited Reaction Processing The growth experiments were carried out at a pressure of 6.0 torr with growth temperatures ranging from 625°C to 1000°C. The growth rate increases rapidly upon the additon of a small germane flow to the dichlorosilane in the reaction-rate-limited growth regime, and can not be explained simply by germanium incorporation. The presence of germane can increase the silicon growth rate by up to a factor of one hundred. Boron doping was also studied at high concentrations of boron in Si and Sil-xGex epitaxial films as a function of diborane flow and growth rate supports a simple kinetic model rather than an equilibrium model.
Spatial Inhomogeneities in Rapidly Thermal-Processed GaAs Wafer
Authors: Usami A. , Kitagawa A. , Wada T. 
Published: March 2011

ABSTRACTThe spatial distributions of the midgap defect (EL2) concentration in semi-insulating liquid-encapsulated Czochralski GaAs wafers have been characterized by the contactless measurement of the optically injected carrier using reflectance microwave probe (RMP) method. The four-fold symmetrical distribution of EL2 in the (100) plane is observed in the 2 inch diameter GaAs wafer after rapid thermal processing(RTP). The deep level distribution in the RTP wafer corresponds to the crystallographic slip generation pattern obtained from x-ray topography. The correlation between the pattern of the redistributed EL2 concentration and the slip generation in the RTP wafer is suggested that the EL2 is produced by the large thermal stress during RTP. Furthermore, the distributions of EL2 center measured by the RMP method are compared with the dislocation patterns in undoped and In-doped GaAs wafers.
High Quality Si and Sil-xGex, Films and Heterojunction Bipolar Transistors Grown by Rapid Thermal Chemical Vapor Deposition (RTCVD)
Authors: Green M. L. , Brasen D. , Temkin H. , Kannan V. C. , Luftman H. S. 
Published: March 2011

ABSTRACTRapid thermal chemical vapor deposition (RTCVD) is a processing technique that results from the combination of radiant heating lamps and a CVD chamber. It is the ultimate cold-wall CVD reactor and allows one to clean wafers in-situ and immediately thereafter deposit epitaxial layers. Very thin layers (<100 Å) can be deposited by either gas or lamp power switching. We report here the growth of high quality Si and Si-Ge layers, both intrinsic and in-situ doped, and the in-situ growth of a heterojunction bipolar transistor. These HJBT's show gains as high as 350 and are promising as microwave transistors. RTCVD processing is a production-worthy technology that will play an important role in the manufacture of future heterostructural devices.
Advanced Single-Wafer Sequential Multiprocessing Techniques for Semiconductor Device Fabrication
Authors: Moslehi Mehrdad M. , Davis Cecil 
Published: March 2011

ABSTRACTSingle-Wafer Integrated in-situ Multiprocessing (SWIM) is recognized as the future trend for advanced microelectronics production in flexible fast turn-around computer-integrated semiconductor manufacturing environments. The SWIM equipment technology and processing methodology offer enhanced equipment utilization, improved process reproducibility and yield, and reduced chip manufacturing cost. They also provide significant capabilities for fabrication of new and improved device structures. This paper describes the SWIM techniques and presents a novel single-wafer advanced vacuum multiprocessing technology developed based on the use of multiple process energy/activation sources (lamp heating and remote microwave plasma) for multilayer epitaxial and polycrystalline semiconductor as well as dielectric film processing. Based on this technology, multilayer in-situ-doped homoepitaxial silicon and heteroepitaxial strained layer Si/GexSil-x/Si structures have been grown and characterized. The process control and the ultimate interfacial abruptness of the layer-to-layer transition widths in the device structures prepared by this technology will challenge the MBE techniques in multilayer epitaxial growth applications.
Fabrication of High Quality Silicide Layers by Ion Implantation
Authors: Reeson Karen J , Veirman Ann De , Gwilliam Russell , Jeynes Chris , Sealy Brian J , Landuyt J , Bussmann Udo , Lindner J K N , Kaat E H te 
Published: March 2011

AbstractBuried layers of CoSi2 have been successfully fabricated in (100) single crystal silicon by implanting 350 keV Co+ to doses in the range 2 - 7 × 1017 cm−2 at a temperature of ∼550°C. For doses ≥ 4 × 101759Co+ cm−2, a continuous buried layer of CoSi2 grows epitaxially, during implantation. After annealing (1000°C 30 minutes) continuous layers of stoichiometric CoSi2 which are coherent with the matrix are produced for doses ≥ 4 × 101759Co+ cm−2. For doses of ≤ 2 × 101759Co+, cm−2, discrete octahedral precipitates of monocrystalline CoSi2 are observed. Isochronal annealing (for 5s) at temperatures in the range 800–1200°C, shows that at temperatures ≥ 900°C there is significant redistribution of the Co from B-type or interstitial sites → substitutional A-type lattice sites. As the anneal temperature is increased there is a corresponding improvement in the crystallinity and coherency of the Si and CoSi2 lattices. This shows that at a given temperature much of the Co redistribution takes place within the first 5s of the anneal.
Formation of Buried Iridium Silicide Layer in Silicon by High Dose Iridium Ion Implantation
Authors: Yu K. M. , Katz B. , Wu I. C. , Brown I. G. 
Published: March 2011

AbstractWe have investigated the formation of IrSi3 layers buried in <111> silicon. The layers are formed by iridium ion implantation using a metal vapor vacuum arc (MEVVA) high current metal ion source at room temperature with average beam energy = 130 keV. Doses of the Ir ions ranging from 2×1016 to 1.5×1017/cm2 were implanted into <111> Si. The formation of IrSi3 phase is realized after annealing at temperatures as low as 500°C. A continuous IrSi3 layer of =200 Å thick buried under =400 Å Si was achieved with samples implanted with doses not less than 3.5×1016/cm2. Implantated doses above 8×1016/cm2 resulted in the formation of an IrSi3 layer on the surface due to excessive sputtering of Si by the TI ions. The effects of implant dose on phase formation, interface morphology and implanted atom redistribution are discussed. Radiation damage and regrowth of Si due to the implantation process was also studied.