bluuebunny/crossref_metadata_2025_split huggingface dataset:
Achieve of High-Quality GaAs N-Type Ion Implanted Layer
Authors: Jinsheng Luo , Tangsheng Chen 
Published: March 2011

ABSTRACTWe have found that co-implantation of phosphorus (P) with Si into SI-GaAs caq improve the quality of ion implanted layer. Hall mobilities of 4600–4700 cm2/Vs and activation efficiencies of 75–85% are obtained. These results are better than those obtained from the samples without P co-implantation. Schottky-barrier technique measuerments show a better mobility profile for the samples with P co-implantation. DLTS measurements show that the number of deep levels and their concentrations decrease. We think that P atoms occupy As vacancies and enhance the activation efficiency and their uniformity. The damage produced under the Si-implanted layer by P co-implantation increases the average Hall mobility.
Implant Isolation Mechanisms in GaAs, AlGaAs, InP and InGaAs
Authors: Pearton S. J. , Abernathy C. R. , Hobson W. S. , Von Neida A. E. 
Published: March 2011

ABSTRACTWe have investigated the thermal stability of high resistivity regions introduced by ion bombardment of GaAs, AlGaAs, InP and InGaAs. For low doses in which the ion species density is below that of the doping density in the target material, we obtain the usual damage-related compensation in which deep levels created by the bombardment trap the charge carriers. By this method one creates material with resistivities around 108 Ω/□ (n- or p-type GaAs and AlGaAs, p-type InP), around 106 Ω/□ (n-type InP) or around 105 Ω/□ (n-type InGaAs or p-type InGaAs), with a return of the initial resistivity after elevated temperature annealing (∼600°C for GaAs and AIGaAs, ∼500°C for InP and InGaAs). The more interesting case is the use of higher dose implants of species which create chemical deep levels. This occurs for O in n-type AlGaAs where O creates a deep acceptor (Ec-0.49 eV), and Fe in n-type InP and InGaAs, where it is also a deep acceptor. When the concentration of these species exceeds the doping density in the material, the bombarded regions retain their high resistivity even after high temperature annealing (> 1000°C for GaAs and AIGaAs, >850°C for InP and InGaAs). The case of O in GaAs appears to represent a third mechanism; it creates thermally stable material only in the case of Be-doped GaAs, suggesting an ion-pairing reaction.
Outdiffusion of Magnesium from Mg + implanted GaAs.
Authors: Baratte H. , Jackson T. N. , Sadana D. K. , Degelormo J. F. , Scilla G.J. , Cardone F. 
Published: March 2011

ABSTRACTMagnesium implanted at high doses (1×1014cm−2 for a 120keV implant energy) into GaAs diffuses out of the crystal upon annealing. The outdiffusion is reduced, but not eliminated, when rapid thermal annealing is employed rather than furnace annealing. We have investigated various mechanisms that may explain this large outdiffusion. The high vapor pressure of the magnesium is not responsible for the outdiffusion since beryllium, which has a low vapor pressure, also outdiffuses. The presence of oxygen in the anneal ambient mostly leads to significant GaAs surface etching. The etching is more pronounced in the case of shallow energy and high dose implants, which suggests some oxygen- magnesium interaction mechanism. A high level of damage at the GaAs surface in the case of shallow magnesium implantation at high dose may also favor rapid outdiffusion of interstitial magnesium.
Comparison of Low Vapor Pressure Organoarsenic Compounds for Movpe Growth of GaAs
Authors: Lum R.M. , Kiingert J.K. 
Published: March 2011

ABSTRACTWe have investigated the use of various alkylarsine compounds as alternatives to arsine in the metalorganic vapor phase epitaxy (MOVPE) of GaAs. These As-precursors, which include homologues of methyl, ethyl and butyl-based compounds, are typically low vapor pressure liquids and thus much safer to handle than arsine, which is a toxic high pressure gas. To enable a direct comparison of the alkylarsine and arsine sources, measurement of their growth and thermal decomposition properties were obtained in the same reactor under identical conditions. The composition and purity of the precursor compound was observed to affect both the film growth rate and its electrical and optical properties.
Mechanism of Au-GaAs Reaction and Effects on Ohmic Formation
Authors: Yeh L. Lu-Min , Holloway P. H. 
Published: March 2011

ABSTRACTReactions between Au and GaAs occurs during alloying of Au-based ohmic contacts on GaAs. The reaction and electrical properties of annealed Au/GaAs contacts have both been studied. The extent of the Au-GaAs reactions increased with annealing temperature, incorporated Ga and As into the Au film and left pits on the GaAs surface. The activation energy for these reactions was determined to be 17.6 kcal/mole. Analysis of size evolution of reaction pits on GaAs proved that GaAs regrows at long time annealing. A mixed GaAs dissolution-regrowth mechanism is proposed for annealing temperature and time similar to those used to form alloyed ohmic contacts. Increased surface carrier concentrations resulting from accumulation of dopants near the Au/GaAs interface is proposed to enhance ohmic contact formation.
Properties of WSix-Schottky Diodes on n-Type GaAs Sputtered under UHV Background Conditions
Authors: Pletschen W. , Kaufel G. , Maier M. , Olander E. , Wiegert J. , Bachem K. H. , Rupprecht H. S. 
Published: March 2011

ABSTRACTMultilayered WSix films for use as gates in a self-aligned refractory gate process of GaAs MESFETs have been RF sputtered onto GaAs wafers under UHV background conditions in order to study their structure and morphology as well as their contact electrical properties. Annealed films deposited at 300°C with single layer thickness of 6 and 3 nm for W and Si respectively have a smooth morphology free from cracks and blisters and show a good adhesion to the substrate. Schottky diodes prepared on n-GaAs exhibit an almost excellent I-V characteristics with a barrier height of 0.73 V and an ideality factor of 1.11. In addition E - and D-FETs fabricated on implanted s.i. wafers have good electrical parameters with transconductances of 200 mS/mm at 1 μm gate length.
Semiconductor Optoelectronic Device Fabrication Using Dry Etching
Authors: Carter Adam J. , Thomas Ben , Morgan David V. , Bhardwaj Jyoti K. 
Published: March 2011

ABSTRACTPlasma etching of GaAs and InP using a CH4/H2 process gas and AlxGa1−xAs using a SiCl4 plasma are reported. Particular attention to etching characteristics as a function of gas and material composition, r.f. power, pressure and temperature are shown. Etching of GaAs and InP highlight two separate etching mechanisms. Surface roughness data at the etched surface is presented and Cl and CH4/H2 process chemistries are compared which shows the latter to yield significant improvements in etch surface characteristics.
Buried-shallow-implant (Bsi) process for High Efficiency Microwave power Mesfets
Authors: Liu S. G. , Capewell D. R. 
Published: March 2011

ABSTRACTWe present a hybrid implant epitaxy process that alleviates the inherent depth-width-dependent limitation of ion implantation. This technique allows shallow implants, which produce a thin active N layer with a controlled doping gradient, to be buried at an arbitrary depth below the less-critical, epitaxiallygrown surface layer. The formation and characteristics of GaAs buried shallow-implant (BSI) layers for microwave power FETs will be discussed.
Metal-Organic Chemical Vapor Deposition of InSb on Gaas and InSb in an Inverted Stagnation Point Flow Geometry
Authors: Hebner G. A. , Biefeld R. M. , Killeen K. P. 
Published: March 2011

ABSTRACTSeveral properties of InSb such as high mobility and narrow bandgap make it an attractive candidate for many unique devices. We have examined the metalorganic chemical vapor deposition (MOCVD) of InSb on GaAs and InSb substrates under a variety of conditions using trimethylindium and trimethylantimony sources. The absolute metal-organic partial pressures above the susceptor were monitored using in-situ Ultraviolet (UV) absorption spectroscopy. X-ray studies of the homoepitaxial growth of InSb on InSb substrates (100) indicate good crystalline epitaxial growth while the x-ray peak for the InSb grown on GaAs (100) is broadened due to defects. Room-temperature Hall mobility measurements performed on the heteroepitaxial InSb layer on GaAs substrates indicates that the mobility of the InSb increases with increasing layer thickness. Mobilities range from 12,000 cm2/V sec for 0.8 micron layers to 38,000 cm2/V sec for 7.4 micron layers. The carrier concentrations are relatively constant (2 to 4 × 1016 cm−3 ) for the n type InSb deposited layers.
The Influence of Sb Doping on the Growth and Electronic Properties of GaAs(100) and AIGaAs(100)
Authors: Bensaoula A. , Jamison K.D. , Chen H.C. , Ignatiev A. 
Published: March 2011

ABSTRACTThe effect of the group V isoelectronic dopant antimony (Sb) on the optimum growth temperature for GaAs and AIGaAs MBE grown films is examined with the aim of producing heterostructures at the lowest possible temperatures. RHEED intensity oscillations have been used to quantify the incorporation rate of Ga, Al, and As for different growth temperatures. The electrical properties of the layers are characterized using photoluminescence spectroscopy (PL), Hall mobility measurements, and deep level transient spectroscopy (DLTS). Results show that isoelectronic Sb doping of GaAs and AIGaAs permits the growth of these materials at temperatures up to 800C lower than optimum, with deep level trap densities, photoluminescence quality, and Hall mobilities at least comparable or better than those films grown at optimal temperatures.
Growth of InGaAsP films in a Multi-Wafer high Speed Rotating Disk Reactor by Mocvd
Authors: Reinert Paul , Mckee Mark , Norris Peter E. , Stall Richard A. 
Published: March 2011

AbstractAs the demands for InP epitaxial materials grow, the need for larger throughput growth techniques becomes important. However, uniformity of thickness and particularly composition of InGaAs and InGaAsP films has proved troublesome. This has limited much of the InGaAsP growth work to single wafer machines. The purpose of this work is to demonstrate good film properties and uniformity on a multi-wafer machine that holds three, two-inch diameter wafers.
Non-Hydride Group V Sources for Omvpe
Authors: Stringfellow G.B. 
Published: March 2011

AbstractA major limitation to the continuing development of organometallic vapor phase epitaxy (OMVPE) for the growth of II/V semiconductor materials is the hazard posed by the hydride sources, AsH3 and PH3, which are virtually universally used, in high pressure cylinders, as the group V source materials for the growth of the highest quality materials. The set of stringent requirements for an organometallic group V source, which includes a high vapor pressure (>50 Torr) and freedom from undesirable carbon contamination, eliminates most commonly available non-hydride group V sources. Recent research on newly developed sources has shown considerable promise. The entire area of group V sources, including the elemental sources, for OMVPE growth of II/V materials will be reviewed. The sources with no hydrogen atoms attached to the group V atom, the elemental, trimethyl-V, and triethyl-V, sources all appear to give unacceptably high carbon incorporation, as does dimethylarsine. Diethylarsine, which has one H attached to the As, produces high quality GaAs. Tertiarybutylarsine (TBAs) and tertiarybutylphosphine (TBP) appear to be promising source materials. TBP has a very low toxicity, a vapor pressure ideal for OMVPE growth, and the pyrolysis occurs at lower temperatures than for PH3. No carbon contamination can be attributed to the TBP. Control of the As/P ratio in OMVPE grown GaAsP is much improved for TBP as compared with PH3 due to the more rapid pyrolysis. TBAs has similar attributes including a favorable vapor pressure and lower pyrolysis temperature than AsH3. The substitution of TBAs for AsH3 results in no observable increase in carbon in the epitaxial GaAs. Phenylarsine is a similar source, with a phenyl radical substituted for a single H atom on AsH3. The vapor pressure of phenylarsine is quite low and the pyrolysis temperature is expected to be some what lower than that for AsH3. Limited results indicate that carbon incorporation in GaAs is acceptable only when TEGa is the group V source.
Gas Phase and Surface Reactions of Organometallic Arsenic Sources
Authors: Omstead T.R. , Brandon S. , Hoveland M. , Jensen K.F. , Bohling D.A. , Muhr G.T. 
Published: March 2011

AbstractThe chemical kinetics of two new organometallic arsenic substitutes, tris-trifluoromethylarsenic (As(CF3)3) and phenylarsine (PhAsH2), for use in the MOCVD of GaAs have been characterized through the use of microbalance gravimetry and molecular beam mass spectrometry. Both growth rate and gas-phase cracking studies demonstrate that phenylarsine interacts only slightly with the common gallium precursors, which may make it a useful alternative to arsine. Growth with tris-trifluoromethylarsenic is achieved only at low V/III ratios and with pressures above 250 Torr. The compound etches GaAs under most conditions.
GaAs Solar Cell Using an Alternate Arsenic Source
Authors: Sundaram V. S. , Avery J. E. , Girard G. R. , Hager H. E. , Thompson A. G. , Fraas L. M. 
Published: March 2011

AbstractUsing an alternate arsenic source, namely, Tertiary Butyl Arsine, a concentrator GaAs solar cell has been grown in a low pressure metal organic chemical vapor deposition reactor. Under 72 sun, air mass 1.5 illumination, the cell had an open circuit voltage of 1.1 V, a fill factor of 83% and an overall efficiency of 21%.
The Use of Group V Alkyls as Replacements for Arsine and Phosphine in Hot-Walled VPe Reactors
Authors: Buckley D. Noel 
Published: March 2011

AbstractThe replacement of arsine and phosphine in a hot-walled VPE reactor by Group V alkyls is described. Epitaxial layers of lnP and InGaAs were grown using trimethylarsenic and trimethylphosphorus respectively. The surface morphology obtained was equivalent to that of samples grown using arsine and phosphine. InGaAs samples with no intentional doping were n- type with a background carrier concentration of 6 × 1015 cm−3, about 3 times higher than that of comparison samples grown using arsine. Mobilities measured at 77 K and 300 K respectively were similar to those measured for corresponding samples grown using arsine, suggesting that no significant carbon incorporation occurred. InP was n-type with a background carrier concentration of 3-6 × 1017 cm−3, significantly higher than that of samples grown using phosphine. Preliminary SIMS measurements on the layers suggest that this is due to silicon-based impurities in the trimethylphosphorus. Results reported for MOCVD using arsenic and phosphorus alkyls are contrasted with present results for a hot-walled reactor.
Large-Area Deposition of GaAs by Mocvd
Authors: Daly James T. , Roberts Carson B. 
Published: March 2011

AbstractA new, large-scale, barrel-type MOCVD reactor which is capable of pro- ducing seven 3-inch wafers or fourteen 2-inch wafers at a time has been developed. Experiments and computer modelling studies of this geometry have been performed. The physical and electronic properties of n-type GaAs as a function of growth conditions are presented. Through the use of experimental design methods, the growth process has been optimized to yield highly uniform growth rates. The demonstrated uniformity supports the use of this reactor for production environments requiring 3-inch wafers.
Growth and Characterization of Heteroepitaxial GaAs on Semiconductor-on-Insulator and Insulating Substrates
Authors: Humphreys T.P. , Das K. , Parikh N.R. , Posthill J.B. , Nemanich R.J. , Miner C.J. , Sukow C.A. , Summerville M.K. , Ross P.L. , Markunas R.J. 
Published: March 2011

AbstractA systematic study pertaining to the molecular beam epitaxial growth and charac- terization of GaAs films on various crystallographic orientations of sapphire is presented. For integration with silicon circuitry, heteroepitaxial GaAs layers have also been grown on commercially-available chemical vapor deposited silicon-on-sapphire (SOS) and SOS substrates that have been upgraded by the double solid-phase epitaxy process.
Atomic Layer Epitaxy of GaAs on Si by Mocvd
Authors: Karam N.H. , Haven V.E. , Vernon S.M. , Tran J.C. , El-Masry N.A. 
Published: March 2011

AbstractEpitaxial GaAs films have been deposited on Si substrates using Atomic Layer Epitaxy (ALE) for the first time. This has been achieved in a SPI-MO CVD™ 450 reactor especially modified foroALE. After an initial high temperature bakeout, a nucleation layer 100-300 Å thick was deposited by ALE. Film growth was then resumed by conventional MOCVD to achieve the desired film thickness. The surface morphologies of the deposited films were found to be comparable to current state of the art conventional GaAs on Si films deposited by the two-step growth process in the same reactor.Selective area epitaxy of GaAs on Si has also been achieved on Si02-coated and patterned Si wafers. The standard two-step deposition technique resulted in epitaxial growth in the patterned windows and poly-GaAs on the oxide mask, while ALE growth resulted in deposition only in the etched windows with no poly-growth on the oxide mask. We will report on the potential of this new deposition technique in producing high quality GaAs-on-Si films.
Electronic Properties of Dislocations in Heavily Dislocated Quantum well Structures: Doping Effects
Authors: Liu T. Y. , Petroff P. M. , Kroemer H. , Gossard A. C. 
Published: March 2011

AbstractIn heavily dislocated GaAs (dislocation density of 108cm-2), the low-temperature cathodo- luminescence efficiency of quantum wells and superlattices is dramatically higher than that of a bulk-like layer. Furthermore, the luminescence efficiency can be further improved by doping the barriers of the GaAs/(Al,Ga)As multi-quantum well structures with beryllium (Be). Two quite different possible models for this observation are discussed: One assumes that the effect is due to the expulsion of dislocation kinks from the wells, the other that it is due to the effect of well width fluctuations.
Near Gap Photoluminescence of GaAs Grown Directly on InP
Authors: Schnoes M. Lamont , Harris T.D. , Hobson W.S. , Lum R. M. , Klingert J. K. 
Published: March 2011

AbstractWe present a detailed photoluminescence and photoluminescence excitation study of GaAs grown directly on InP substrates by MOCVD. Reliable peak assignments are determined. With these peak assignments, we measure strain and strain uniformity, identify impurities, and assess material quality. Most samples exhibit three distinct spectral features. The two highest energy features are the strain split valence band, the third feature is a carbon impurity. The observed splitting is in good agreement with the value predicted from the thermal expansion mismatch.
Transient Photoconductivity in GaAs Films Grown by Molecular Beam Epitaxy.
Authors: Werner A. , Moustakas T. D. , Kunst M. 
Published: March 2011

AbstractHahn-Meitner-Institut, D-1000 Berlin 39, W. Germany Abstract The transient photoconductivity, in MBE grown silicon doped GaAs films, was studied by a contactless microwave conductivity technique. The dark carrier concentration of the investigated films varies from 4 x 1014 cm-3 to 6 x 1017 cm-3. At least two decay channels can be distinguished. An initial fast decay process (t<20 ns), which is excitation intensity dependent, followed by a slower one. The fast decay is tentativly identified with a direct electron-hole recombination and is more pronounced at high excitation intensities and in low impurity materials. The slower decay component is characterized by effective electron lifetimes ranging from 2 µs for low impurity fims up to 100 µs for high impurity samples. It can be concluded that an increase of the Si-concentration leads to an increase in the concentration of hole traps, which quenches the initial electron-hole recombination and decreases the electron decay rate in the microsecond region.
Growth of AlGaAs/GaAs Modfet Structures by Gsmbe Using Triethylalkyls and Arsine
Authors: Houng Yu-Min , Pao Yi-Ching , Mcleodl Paul 
Published: March 2011

AbstractWe have grown high quality AlGaAs/GaAs heterostructures by GSMBE, using triethylalkyls and arsine, for MODFET device applications. Al.28Ga.72As/GaAs modulation-doped structures with moblilities as high as 7,200 and 47,000 cm2/V-s at 300 and 77K, respectively, were obtained for a spacer layer thickness of 30Å and a sheet carrier concentration of l×l012cm−2. These results are comparable to films of a similar structure grown by elemental source MBE or by OMVPE techniques. Quarter-micron gate length MODFETs fabricated from this material have fr greater than 38 GHz and exhibit a 1.7 dB noise figure with 10 dB associated gain at 18 GHz when operated at room temperature.
InGaAs/InP Multiquantum well Structures Grown by Trichloride Vapor Phase Epitaxy
Authors: Wang K. W. , Mattera V. D. , Tai K. , Chu S. N. G. , Roccasecca D. D. , Luther L. , Livescusecca G. 
Published: March 2011

AbstractLong wavelength (l.3pm<X<l.551un) InGaAs/InP multiquantum well (MQW) PIN structures in which the quantum confined Stark effect can be observed, are of particular interest because of their potential for high modulation contrast ratios and high speed operation. The chemistry of trichloride VPE lends itself to the growth of high purity InGaAsP heterostructures which are essential for the realization of high performance optical modulators and switches. In this study, we investigate the application of multi-frit trichloride VPE for the highly uniform epitaxial growth of InGaAs/InP MQW structures on two-inch InP substrates for advanced photonic device applications. The growth of MQW structures with various well thicknesses was studied as was the effect of substrate orientation. The structures have been characterized by infrared absorption and photoluminescence spectroscopy, cross-sectional transmission electron microscopy and double crystal x-ray diffraction.
A Study on Film Precursors in SiH4 Thermal CVD by use of Trench Coverage Measurements
Authors: Yuuki Akimasa , Kawahara Takaaki , Matsui Yasuji , Tachibana Kunihide 
Published: March 2011

ABSTRACTThe precursors of Si film in SiH4 low pressure thermal CVD are studied by use of the trench coverage analysis. The cross sectional profile of the film deposited in a trench is simulated by a direct Monte-Carlo method using the composition of the precursors and their sticking probabilities as adjustable parameters. A comparison with the experimental results[1] shows that the trench coverage profiles are well reproduced by the model where two kinds of precursors deposit independently with respective sticking probabilities of almost zero and unity. The former is silane molecule, and the latter is radicals produced by gas phase reactions. The deposition rate due to radicals can be estimated from the comparison. Considering the sticking probability and the SiH4 pyrolysis reactions, it is concluded that H3SiSiH is one of ate dominant film precursors in gas phase reaction products.