bluuebunny/crossref_metadata_2025 huggingface dataset:
Modulated barrier photodiode: A new majority-carrier photodetector
Authors: Chen C. Y. , Cho A. Y. , Garbinski P. A. , Bethea C. G. , Levine B. F.
Published: February 2003

A new majority-carrier photodetector, called a modulated barrier photodiode (MBP), grown by molecular beam epitaxy has been developed. In sharp contrast to a bipolar phototransistor, the optical gain of MBP increases with decreasing incident power. An optical gain of 1000 at 1.5 nW incident power and a fall time of 600 psec have been obtained. In addition to the application for uses as a detector in an optical communication system, the device points to the feasibility of realizing a solid-state triode.
Ductile extension of a lenticular bubble under high-energy ion bombardment with relation to blistering and flaking
Authors: Kamada K. , Higashida Y.
Published: February 2003

A theory is given which is based on a model of the ductile extension of a crack in a material and is capable of explaining the whole process of surface exfoliation phenomena under high-energy ion bombardment, including both blistering and flaking, on the same ground, starting from a very small nucleus of a lenticular bubbble. Further, the distinction between blistering and flaking is clarified, and the relation of the exfoliation phenomeon with local swelling due to bubble formation is presented.
Brittle behavior of explosives during high acceleration
Authors: Lanzerotti M. Y. D. , Sharma J.
Published: February 2003

The mechanical behavior of explosives subjected to sustained constant acceleration greater than 104 g has been studied in an ultracentrifuge. The explosives are found to behave as brittle solids. Particles break loose from a surface exposed to the acceleration. The fracture is believed to occur at grain boundaries when the tensile or shear strength is exceeded.
Self-sustained intensity oscillation of a laser diode introduced by a delayed electrical feedback using an optical fiber and an electrical amplifier
Authors: Nakazawa Masataka , Tokuda Masamitsu , Uchida Naoya
Published: February 2003

A self-sustained oscillation of laser light intensity emitted by a laser diode was newly observed by a delayed network using an optical fiber and an electrical feedback system. The time delay (transit time) of the light beam through the optical fiber plus the time delay of the electrical signal in the electrical feedback system determines the oscillation frequency of the light intensity. The oscillation for the fiber length of 7 km was obtained by using an electrical amplifier with large gain. With a wide-band amplifier, harmonic (multimode) oscillations took place where the waveform was almost square.
Optical frequency shifting lever
Authors: Chicklis E. P. , Esterowitz L. , Eckardt R. C. , Allen R.
Published: February 2003

Multiplication of the frequency shift of a tunable solid-state laser is achieved via resonant pumping in a double-doped rare-earth crystal. With a tuning shift of only 0.6 nm of the pump, an output shift of 100 nm is achieved.
The radiative recombination coefficient of GaAs from laser delay measurements and effective nonradiative carrier lifetimes
Authors: ’t Hooft G. W.
Published: February 2003

The various interpretations of turn-on delay in semiconductor laser diodes are critically reviewed. It is concluded that values for the total carrier lifetime, or radiative coefficient, cannot be deduced unambiguously from laser turn-on delay measurements alone. However, using additional luminescence efficiency measurements in the spontaneous regime, both the radiative coefficient as well as the nonradiative lifetime can be calculated. The average value for the radiative coefficient in GaAs obtained in this way is 1.3×10−10 cm3/s.
Light-current characteristics of InGaAsP light emitting diodes
Authors: Temkin H. , Chin A. K. , DiGiuseppe M. A. , Keramidas V. G.
Published: February 2003

Light-current characteristics of 1.3-μm InGaAsP light emitting diodes were investigated as a function of temperature between 70 and 350 K. The sublinearity of the light output found at high injection levels was shown to be temperature independent and similar in magnitude to that observed in GaAlAs devices. These experimental results cannot be explained with the previously proposed models of in-plane superluminescence and Auger recombination.
Thermal redistribution of oxygen during solid-phase regrowth of arsenic-implanted amorphized Si
Authors: Magee T. J. , Leung C. , Kawayoshi H. , Ormond R. , Furman B. K. , Evans C. A. , Day D. S.
Published: February 2003

Redistribution and gettering of mobile oxygen into damage regions of As-implanted (111) Si have been investigated using transmission electron microscopy and secondary ion mass spectrometry profiling. Rapid motion and gettering of 16O into near-surface regions and zones at depths ≃RP have been shown to occur during and subsequent to solid-phase regrowth of the amorphous layer. The presence of residual defects in the form of twinning zones, stacking faults, and dislocation lines serves to provide effective pinning sites for SiOx nucleation and produce increased gettering of oxygen during secondary annealing.
Reactive laser-evaporation for hydrogenated amorphous silicon
Authors: Hanabusa M. , Suzuki M.
Published: February 2003

Hydrogenated amorphous silicon films have been deposited by laser-induced evaporation in a hydrogen atmosphere. The present work demonstrates that reactive laser evaporation is feasible despite its extraordinary accumulation rates (106 Å/s). Electrical resistivity increased by six orders of magnitude upon hydrogenation, and infrared measurements exhibited vibrational absorption characteristic of silicon-hydrogen bonds. At a laser-irradiated target spot, molecular hydrogen is thermally dissociated, as revealed by emission studies, and the atomic hydrogen thus generated is believed to be accumulated with silicon atoms on a substrate.
Charge neutrality in heavily doped emitters
Authors: del Alamo Jesús A.
Published: February 2003

The applicability of the quasineutrality approximation to modern emitters of solar cells is analytically reviewed. It is shown that this approximation is fulfilled in more than 80% of the depth of a typical solar-cell emitter, being particularly excellent in the heavily doped regions beneath the surface where most of the heavy doping effects arise. Our conclusions are in conflict with Redfield’s recent affirmations.
Hydrogen effusion under 6–7-MeV 15N ions irradiation in oxygen-contaminated thin films of sputtered a-Si:H
Authors: Fallavier M. , Thomas J. P. , Tousset J. , Monteil Y. , Bouix J.
Published: February 2003

We report on the modification of rf-sputtered a-Si:H thin films induced by high-energy ion bombardment and which occurs during hydrogen analysis using the 1H(15N, αγ) 12C nuclear reaction. We find that hydrogen losses under ion bombardment occur for films containing oxygen impurities and that they are directly related to the oxygen contents. We show from infrared transmission measurements that the lost H comes from the dissociation of the Si–H bond in (SiH2)n and O–Si–H complexes induced by ionization processes along the ion trajectory in the film. These observations are a strong indication of the inhomogeneous structure of the O-containing material.
Optical pulse compression in a cholesteric liquid crystal
Authors: Ghosh Roy D. N. , Narasimha Rao D. V. G. L. , Bronk H.
Published: February 2003

A 20-ns laser pulse is compressed to nearly 2.5 ns in a 10-cm-long sample of liquid-crystal cholesteryl oleate in the isotropic phase. Pulse compression in a length as short as only 5 cm has been observed. A semiquantitative explanation is given in terms of stimulated Brillouin scattering.
Surface acoustic wave parametric oscillation in Si-on-LiNbO3
Authors: Nakagawa Yasuhiko , Wakuda Mutuo , Kobayashi Kenichi
Published: February 2003

The observation of a surface acoustic wave parametric oscillation in Si-on-LiNbO3 is reported. The threshold power required for parametric oscillation was substantially reduced by the highly efficient surface acoustic wave reflectors. Experimental frequency was 130 MHz, and the conversion efficiency from the pumping to the surface acoustic waves was about −21 dB.
Reliability of pulsed electron-beam-alloyed AuGe/Pt ohmic contacts on GaAs
Authors: Lee C. P. , Welch B. M. , Tandon J. L.
Published: February 2003

Reliability of pulsed electron-beam-alloyed AuGe/Pt ohmic contacts on GaAs has been studied and compared with thermally alloyed contacts. Electron-beam-alloyed contacts have excellent surface morphology and low contact resistance, but are not as reliable as thermally alloyed contacts; the specific contact resistance deteriorates with thermal aging at 250 °C. The degradation is explained by the interdiffusion and compound formation in the metals during aging.
Magnitude of the intrinsic resonant frequency in a semiconductor laser
Authors: Paoli Thomas L.
Published: February 2003

The magnitude of the intrinsic resonant frequency exhibited by a semiconductor laser operating at a fixed level above threshold is shown to be determined by the product of the photon lifetime for the unpumped laser cavity and the differential lifetime of the carriers at threshold. This conclusion differs from the generally accepted view that the relevant lifetimes for the resonant frequency are the carrier and photon lifetimes evaluated at threshold and resolves the existing discrepancy between measured and calculated values. The present analysis is used to evaluate the shift in the resonant frequency produced in a typical proton-bombarded stripe-geometry laser by variations in the laser’s cavity loss.
Infrared pulsed opto-acoustic spectroscopy
Authors: Nelson E. T. , Patel C. K. N.
Published: February 2003

We report the first pulsed opto-acoustic spectroscopy of low loss condensed media in the infrared region. Stimulated Raman scattering in high-pressure hydrogen gas was used for down shifting pulsed tunable dye laser radiation through first- and second-order Stokes processes. Measurements of the absorption spectra of liquid ethylene in the region of 0.7–1.6 μm indicate the general applicability of this technique to other important problems.
Rapid isothermal annealing of ion implantation damage using a thermal radiation source
Authors: Fulks R. T. , Russo C. J. , Hanley P. R. , Kamins T. I.
Published: February 2003

The rapid annealing of ion implantation damage in silicon using the radiation from a graphite heater has been demonstrated. Complete 3-in.-diam wafers were annealed in a single 10-sec exposure with high activation for implants of boron (50 keV; 1×1015 cm−2) and moderate activation for high-dose arsenic implants (140 keV; 6×1015 cm−2). Dopant redistribution was ∼1000 Å for boron and ∼200 Å for arsenic. Leakage currents of implanted p+n and n+p diodes were comparable to those of furnace-annealed control wafers and indicate good crystallinity in the depletion region near the junction. Diode leakage uniformity across the wafers was also excellent. C-V measurements on oxides annealed by this technique showed flatband voltages within 0.5 V of those measured on control wafers. This method of annealing implant damage is a practical alternative to those involving more elaborate power sources such as lasers, electron beams, or high-intensity arc lamps.
The role of stabilized back-surface damage in controlling internal SiOx nucleation and denudation zones in Si
Authors: Magee T. J. , Leung C. , Kawayoshi H. , Furman B. K. , Evans C. A.
Published: February 2003

Using two-step annealing of wafers containing mechanically induced back-surface damage, we have shown that the presence of stabilized damage regions controls the development of front-surface defect denudation zones and internal SiOx nucleation. Using data from transmission electron microscopy, secondary ion mass specrometry profiling, and secondary ion microscopy measurements we have demonstrated that little or no direct correlation exists between measured (front-surface) oxygen depletion widths and defect denudation zone widths. Primary anneals at temperatures <600 °C have also been shown to produce no significant or measurable depletion of oxygen at the front surface of wafers.
Electron bombardment induced conductivity in amorphous silicon
Authors: Hatanaka Yoshinori , Oi Hiroyasu , Ando Takao
Published: February 2003

The electron multiplication factors of electron bombardment induced conductivity (EBIC) of 300–500 were obtained with a hydrogenated amorphous silicon (a-Si:H) film of higher resistivity than 1010 Ω cm at an accelerating voltage of 7 kV. The response time of the EBIC current for a pulsed primary electron beam was determined to be shorter than 1 ms for both build-up and decay lags. It is found that an EBIC target of an a-Si:H film has promising properties for application to imaging devices at low light levels.
Quasiparticle-induced coupling effects between two superconducting weak links
Authors: Neumann L. G. , Dai Y. D. , Kao Y. H.
Published: February 2003

Interactions between two independently biased thin-film superconducting microbridges yield a voltage step in the current-voltage characteristics of the bridges. Perturbation theory applied to the quasiparticle coupling currents explains these results as apparent critical current depression due to a regenerative feedback effect. Calculated changes in the critical current caused by the combined effects of order parameter depression, dc and ac quasiparticle coupling currents are in good agreement with experiments.
Thermal fluctuations and the phase locking of two nearby Josephson junctions
Authors: Ambegaokar Vinay , Arai Makoto R.
Published: February 2003

The dynamics of two small-capacitance, weakly coupled Josephson junctions are analyzed, including thermal noise. The phenomena of phase locking, line narrowing, and coherence emerge from the calculation, which provides the basis for a semiquantitative understanding of recent experimental work on this system.
Dependence of implanted Se and S profiles on GaAs implantation temperature and crystallinity
Authors: Wilson Robert G. , Jamba Douglas M.
Published: February 2003

Atom depth distributions of Se implanted into GaAs show that the deep sides of the depth distributions are the result of interstitial diffusion of Se during implantation of crystalline GaAs. The effect saturates at an ion fluence of ∼1014 cm−2 for 25 °C implants and continues uninhibited up to the 1016 cm−2 fluence for 250 °C implantation temperature, implying that the GaAs implantation damage is annealed during implantation at 250 °C. Annealed Se profiles are unchanged for all fluences for both 25 and 250 °C implantation temperatures. Se implants into a self-amorphized GaAs surface yield more abrupt profiles than corresponding ones into crystalline GaAs, further indicating that when crystal channels are absent, implant tails are absent. Sulfur implants into crystalline and amorphized GaAs held at −130, 25, and 250 °C show that S behaves like Se for the unannealed case; the profiles for implants into crystalline GaAs are deeper the higher the substrate temperature during implantation, implying that diffusion or migration occurs during implantation. In contrast to the results for Se, the annealed S profiles redistribute significantly, characterized both by diffusion deeper into the GaAs and by redistribution toward the surface. These redistributions are significantly impeded by either a cold substrate temperature during implantation or by prior amorphization of the GaAs at any implantation temperature.
Noise effects in an optical heterodyne spectrometer using tunable diode lasers
Authors: Katzberg Stephen J. , Kowitz Herbert R. , Rowland Carroll W.
Published: February 2003

A comparison of measured and predicted signal-to-noise ratio is made in an optical heterodyne spectrometer utilizing a tunable diode laser which exhibited excess noise. It is shown that good agreement between predicted and measured signal-to-noise ratios results if excess noise effects due to tunable diode lasers are included in the predictions. The methods used to quantify excess noise and to incorporate their effects into predictions of signal-to-noise ratio are discussed.
Very low reach-through voltage, high performance AlxGa1−x Sb p-i-n photodiodes for 1.3-μm fiber optical systems
Authors: Capasso F. , Hutchinson A. L. , Foy P. W. , Bethea C. , Bonner W. A.
Published: February 2003

A high performance AlxGa1−x Sb 1.3-μm p-i-n photodiode, operating at a very low reach-through voltage (−1.5 V), has been demonstrated for the first time. The low punch-through voltage was achieved by growing extremely low doped liquid phase epitaxial layer (ND−NA ≃4×1014/cm3). The capacitance is ≃0.4 pF and the dark current ≃20 nA at −1.5 V for a 10−4-cm2 device area. The zero bias external quantum efficiency is ?55% at 1.3 μm; the rise time is 100 ps and the full width at half-maximum (FWHM) is 200 ps. These results indicate that p-i-n photodiodes comparable in performance to homojunction InGaAs p-i-n detectors can be fabricated with the AlGaSb alloy system.
Investigation of the oxidation properties of cw laser formed WSi2
Authors: Shibata T. , Wakita A. , Sigmon T. W. , Gibbons J. F. , Cass T. R.
Published: February 2003

The oxidation properties of WSi2 formed by laser reaction of electron beam evaporated tungsten on silicon substrates are reported. Both steam and dry oxidation processes are investigated in the temperature range 900–1000 °C. Measurements of oxide thickness versus time show similar behavior for both processes (linear changing to parabolic) with essentially no loss of W observed. Transmission electron microscopy investigation before and after oxidation indicates no decomposition of the films and grain sizes growing from 100 to ≳500 nm.
Electron beam pattern generation in thin-film organic dianhydrides
Authors: Schmidt Paul H. , Joy David C. , Kaplan Martin L. , Feldmann William L.
Published: February 2003

Transparent, stable, electrically insulating, crystalline thin films of two aromatic organic dianhydrides, 3,4,9,10-perylenetetracarboxylic dianhydride C24H8O6 and 1,4,5,8-naphthalenetetracarboxylic dianhydride C14H4O6, were prepared by vapor deposition. On exposure to an electron beam dose of 0.05 C cm−2 the written areas of the films appeared visually blackened and were electrically conducting. This chemical transformation was found to be both dose and current density dependent. Fine lines with widths of 1000 Å were prepared by electron exposure at just above writing threshold doses. The chemical and electrical properties of the materials formed upon e-beam treatment were found to be notably different from those of the starting anhydrides and useful for semiconductor device fabrication.
Conductivity enhancement in laser-recrystallized polycrystalline silicon-on-insulator using molecular hydrogen annealing
Authors: Lam H. W.
Published: February 2003

It is found experimentally that a thermal anneal in molecular hydrogen at 450 °C reduces the sheet resistance of a laser-recrystallized polycrystalline silicon layer supported by a silicon dioxide layer. This effect can be reversed by annealing the polycrystalline silicon in nitrogen. The observed electrical characteristics of the polycrystalline silicon are similar to those treated with an atomic hydrogen plasma where grain-boundary potential barrier lowering is believed to be responsible for the reduction in the resistivity.
Photoluminescence of pulsed laser irradiated n- and p-GaAs
Authors: Feldman Bernard J. , Lowndes Douglas H.
Published: February 2003

We report a photoluminescence study of pulsed ruby laser irradiated crystalline and ion implanted GaAs, which supports the following conclusions: (1) pulsed laser irradiation of crystalline GaAs alters both the intensity and the spectrum of photoluminescence, corresponding to an increase in nonradiative recombination centers present in the material; (2) the variation of luminescent intensity with laser energy density is different for n- and p-type materials; (3) no luminescence is detected in high dose ion implanted GaAs, either before or after laser annealing.
Defect states in electron bombarded n-InP
Authors: Levinson M. , Benton J. L. , Temkin H. , Kimerling L. C.
Published: February 2003

A deep level transient spectroscopy study has been made of 1-MeV electron bombarded liquid encapsulated Czochralski grown n-InP Schottky barrier structures. Two previously unobserved shallow defect states were found at very low concentration levels in the unirradiated material, and irradiation resulted in seven new states in the upper-half of the band gap. Introduction rates, electron activation energies, and capture cross sections were examined and a preliminary investigation of annealing behavior was performed. The irradiation induced states all exhibited relatively low introduction rates and large capture cross sections, and three gave evidence of significant defect mobility near room temperature.
A new lateral selective-area growth by liquid-phase epitaxy: The formation of a lateral double-barrier buried-heterostructure laser
Authors: Tsang W. T. , Logan R. A. , van der Ziel J. P.
Published: February 2003

We report a new lateral selective-area growth by liquid-phase epitaxy with the preparation of a new buried-heterostructure laser, the lateral double-barrier buried-heterostructure (DBBH) laser, as an illustrative example. The DBBH laser so prepared operated in a stable clean fundamental mode with reduced optical scattering losses due to sidewall roughness of the etched mesa. Pulsed operation was achieved at temperatures as high as 280 °C. This new selective-area growth can also be used to form guided wave integrated microlens systems.
Use of argon x-ray lines for the diagnosis of laser-produced implosions
Authors: Matthews Dennis L. , Koppel Louis N. , Campbell E. Michael , Larsen Jon T. , Slivinsky V. W. , Lane Stephen M. , Ceglio N. M.
Published: February 2003

We have measured the spatial extent of heliumlike and hydrogenlike argon x-ray lines that were emitted from the fuel region of an imploded laser fusion target directly illuminated by the Argus laser. The diameter of the fuel region measured in this way agrees with that obtained from images of the thermonuclear burn region recorded simultaneously by an alpha-particle zone plate camera. Time-averaged electron temperatures in the target core were determined from argon line intensity ratios and compared to ion temperatures determined from measurements of neutron yield.
Low defect density amorphous hydrogenated silicon prepared by homogeneous chemical vapor deposition
Authors: Scott B. A. , Reimer J. A. , Plecenik R. M. , Simonyi E. E. , Reuter W.
Published: February 2003

Compositional, structural and transport data are presented for amorphous hydrogenated silicon (a-Si:H) prepared by homogeneous chemical vapor deposition (HOMOCVD). We find a remarkable similarity in properties between HOMOCVD and plasma a-Si:H, including a nearly identical range (250–300 °C) for the preparation of highly photoconductive films. However, unlike plasma material, HOMOCVD a-Si:H exhibits negligible photo-induced instabilities (Staebler–Wronski effect) and low spin concentrations over a wide span of deposition conditions. These results indicate that a significant defect-creating reaction, most likely surface Si-H bond scission, is occurring in the plasma environment, but absent in HOMOCVD.
An annular electron beam for longitudinal electron beam pumped high power lasers
Authors: Kawamura Y. , Toyoda K. , Namba S. , Suzuki K.
Published: February 2003

A new pumping scheme was designed for a laser oscillator of a longitudinal electron beam pumped high power laser. In this system, an annular electron beam was converged and guided along the optical axis by a carefully shaped magnetic field which enabled a total reflector of the optical cavity to be placed on the optical axis. For KrF laser oscillation, the output energy and efficiency were 5 J and 4%, respectively.
On the atomic structure of the Σ = 3, {112} twin in silicon
Authors: Fontaine C. , Smith D. A.
Published: February 2003

A new model is proposed for the {112} interface. The essential feature is that the interface region is highly symmetrical and composed of five and seven membered rings, which is contrary to some earlier predictions but consistent with observations of other grain boundaries in materials with the diamond cubic structure.
Tin doping of active region in InGaAsP/InP lasers
Authors: Tamari N.
Published: February 2003

Intentional doping of the quaternary layer with n-type dopant like Sn was found to avoid the problem of p-n junction misplacement in InGaAsP/InP lasers. Accurate and reproducible location of the electrical junction within the active region has been realized. It has been found that the threshold current density as well as T0 of the lasers do not change up to a doping level of ∼4×1018 cm−3 in the active layer. The metallurgical study has shown that the crystalline perfection does not deteriorate by doping with Sn. These results suggest that the active layer can be doped with Sn in a broad concentration range in order to achieve special characteristics of the device (lasers or light emitting diodes) without deterioration of device performance.
A new formula for predicting low-temperature evaporation field
Authors: Forbes Richard G.
Published: February 2003

An elementary formula is derived that enables the approximate prediction of the field strength for low-temperature field evaporation, using chemical thermodynamic data. The new formula closely resembles the familiar Müller–Schottky formula, but its derivation relies only on a general argument concerning energetics, and does not employ the physically dubious arguments concerning potential curves that are implicit in image-hump formalisms. It is suggested that the new formula could usefully supplant the Müller–Schottky formula in elementary discussions of field evaporation.
X-ray response of Daguerreotype photographic plates
Authors: Prohaska R. , Fisher A.
Published: February 2003

The Daguerreotype photographic process uses a thin (300–600 Å) film of silver halide to record a photographic image. Daguerreotype plates were prepared and exposed to 1.5-keV aluminum K radiation. Exposures of 2–8 mJ/cm2 were used. Edge widths of 0.5 μ are observed. The developed image consists of silver amalgam or finely divided metallic silver, depending on the development method used. We describe the process and present scanning electron microscope photomicrographs of sample images.
A technique for rapidly alternating boron and arsenic doping in ion-implanted silicon molecular beam epitaxy
Authors: Swartz R. G. , McFee J. H. , Voshchenkov A. M. , Finegan S. N. , Ota Y.
Published: February 2003

This letter reports the use of boron ion implantation doping during simultaneous growth of silicon molecular beam epitaxy. It describes further a technique for epitaxial growth of abrupt silicon p-n junctions by rapid changeover during growth between boron and arsenic ion beams. This is expected to be of importance in a variety of applications, including, for example, high speed bipolar junction transistors.
Electron concentration dependence of Hall factor in In0.53Ga0.47As
Authors: Takeda Y. , Littlejohn M. A.
Published: February 2003

The Hall factor in In0.53Ga0.47As is calculated as a function of electron concentration between 1×1014 cm−3 and 1×1019 cm−3 at 300 K with carrier compensation ratios (ND+NA )/n = 1,2,5, and 10. The results give a clear relation between the Hall mobility and the drift mobility which has been a very ambiguous relation thus far. Temperature dependence of the Hall factor is also presented at several concentrations.
Regenerative pulsations from an intrinsic bistable optical device
Authors: Jewell J. L. , Gibbs H. M. , Tarng S. S. , Gossard A. C. , Wiegmann W.
Published: February 2003

Regenerative pulsations of the output of a GaAs etalon are reported in good agreement with computer simulations of opposing thermal and free-exciton refractive-index effects.
Low dark current GaAlAsSb photodiodes
Authors: Chin R. , Hill C. M.
Published: February 2003

GaAlAsSb heterostructure low leakage photodiodes have been fabricated. These devices exhibit leakage currents of 7 to 9 nA (25–35 μA/cm2) and capacitances of approximately 1 pF at 20-V reverse bias. The devices are planar Be-implanted structures and have a net donor concentration of 2×1015 cm−3 in Ga1−xAlxAsSb (x∼0.15).
An IR sensitive, real-time imaging technique based on a photoelectrochemical cell
Authors: Micheels Ronald H. , Rauh R. David
Published: February 2003

A real-time imaging technique based on optical saturation phenomena in photoelectrochemical cells has been developed. The long-wavelength spectral sensitivity of these devices extends to the band-gap energy of the semiconductor photoelectrode employed. An image resolution of 180 μ and a response time of better than 100 ms has been obtained with an n-GaAs cell.
The true area of contact at a liquid metal-solid interface
Authors: Timsit R. S.
Published: February 2003

The properties of a liquid-solid interface are usually understood under the assumption that contact is continuous over the entire interface, regardless of the surface roughness of the solid. This letter presents results of an analysis which suggest that this assumption is not valid when the liquid is a metal characterized by weak adhesion to the solid. Under these conditions the true area of contact at the interface depends on the surface microtopology of the solid and may differ considerably from the area of nominal contact. Experimental evidence in support of these conclusions is presented.
Transmission electron microscope observation of dark defects appearing in InGaAsP/InP double heterostructure lasers aged at accelerated operation
Authors: Wakita K. , Takaoka H. , Seki M. , Fukuda M.
Published: February 2003

Transmission electron microscopy contrast analysis is presented to reveal the nature of the defects associated with the active region in degraded InGaAsP/InP double heterostructure lasers. Dislocation loops elongating in the [11̄0] direction and platelike precipitates lying in the {111} planes associated with the above dislocation loops have been observed to correspond to dark spot defects appearing in electroluminescence pattern of the lasers operated at 10-kA/cm2 current density at 250 °C junction temperature.
Depth profiling of metal oxides using Raman spectroscopy with ion bombardment
Authors: Hamilton J. C. , Mills B. E. , Benner R. E.
Published: February 2003

Raman spectroscopy has been combined with ion bombardment to obtain chemical compound identification as a function of depth in films containing Fe2O3. Experiments were performed using Fe2O3 single crystals, oxidized iron foil, and oxidized stainless steel. Low sensitivity to sputter induced chemical changes is a major advantage of the technique, allowing reliable chemical profiles to be obtained for these thin-film oxides.
Change of interface state spectrum in Al/SiO2/Si structures with biasing during electron irradiation
Authors: Rosencher E. , Bois D.
Published: February 2003

The interface states induced in metal-oxide-semiconductor (MOS) capacitors by 25-keV electron beam irradiation have been investigated as a function of gate bias and irradiation dose using deep level transient spectroscopy (DLTS). The results clearly reveal the existence of two types of defects. The first type introduces a flat continuum of levels throughout the Si band gap and is not affected by the MOS gate bias. Another type is created only when a positive bias is applied to the MOS gate during irradiation and accounts for an additional broadband of levels in the midgap region. The physical origin of the bias voltage effect on these levels is briefly discussed.
Monolithic integration of a very low threshold GaInAsP laser and metal-insulator-semiconductor field-effect transistor on semi-insulating InP
Authors: Koren U. , Yu K. L. , Chen T. R. , Bar-Chaim N. , Margalit S. , Yariv A.
Published: February 2003

Monolithic integration of 1.3-μm groove lasers and metal-insulator-semiconductor field-effect transistors (MISFET) is achieved by a simple single liquid phase epitaxy (LPE) growth process. Laser thresholds as low as 14 mA for 300-μm cavity length are obtained. MIS depletion mode FET’s with n channels on LPE grown InP layer show typical transconductance of 5–10 mmho. Laser modulation by the FET current is demonstrated at up to twice the threshold current.
Growth of high quality epitaxial Ge films on (100)Si by sputter deposition
Authors: Bajor G. , Cadien K. C. , Ray M. A. , Greene J. E. , Vijayakumar P. S.
Published: February 2003

Expitaxial Ge films ∼1.5 μm thick, were grown on (100) Si substrates at relatively low temperatures, 470°C, by rf sputter deposition. Low-energy ion bombardment of the substrate and growing film during deposition provided compositional grading of the lattice mismatched interface. X-ray diffraction and electron channeling spectra indicated that the films were single crystals while Hall measurements showed them to be p type with p(300 K)≃1×1017 cm−3 and corresponding carrier mobilities, 1280 cm2/Vs, comparable to the best bulk crystals. The thickness of the compositionally graded junction was found by Auger electron spectroscopy depth profiling to be ∼200 nm. C-V measurements indicated that over this region the net acceptor concentration increased from 4×1014 cm−3 near the substrate surface to the bulk film value of 1×1017 cm−3. Large area p-n diodes exhibited reverse breakdown voltages of ⩾10 V.
Electric properties of unipolar GaAs structures with ultrathin triangular barriers
Authors: Gossard A. C. , Kazarinov R. F. , Luryi S. , Wiegmann W.
Published: February 2003

Unipolar GaAs structures with built-in planar-doped triangular barriers (n-i-p+-i-n) have been investigated experimentally. Current-voltage characteristics of ultrathin (400 Å on each side) barriers have been measured at temperatures ranging from 77 to 450 K. It is found that the characteristic activation energy Ea for current of both polarities strongly depends on temperature, changing from 1.05 eV at room temperature to 0.4 eV at 77 K. Such variation of the activation energy is interpreted as a transition from the thermionic mechanism of current to thermally assisted tunneling.
Effects of two longitudinal optical-phonon modes on electron distribution in GaxIn1−xAsyP1−y
Authors: Takeda Yoshikazu , Littlejohn M. A. , Trew R. J. , Hutchby J. A.
Published: February 2003

GaInAsP quaternary alloys are known to have two or three longitudinal optical (LO)-phonon modes. The two-LO-phonon model was employed for the electron distribution and drift mobility calculations. Perturbation distribution has sharp drops due to the two-LO phonons and these drops cause a further downward bowing of the mobility along the arsenic composition compared with a one-LO-phonon model which has mostly been used.
Ion selective photoelectrochemistry and stabilization by siloxane-coated p-Si electrodes
Authors: Hughes R. C. , Ginley D. S. , Hays A. K.
Published: February 2003

Silicon by virtue of its small band gap and energy-band structure is an attractive candidate for applications in photoelectrochemical devices. Unfortunately it is unstable in most electrolytes of interest. We demonstrate that plasma polymerized hexamethyldisiloxane coatings on silicon photocathodes have several unique and beneficial features. These include enhanced corrosion resistance, ionic selectivity for potential determining species, and high protonic conductivity.
Quenching and enhancement of the exciton and subband-gap absorption in GaAs:Cr using two-beam transverse acoustoelectric voltage spectroscopy
Authors: Davari B. , Das P.
Published: February 2003

Transverse acoustoelectric voltage (TAV) spectroscopy of GaAs:Cr samples is performed. Samples are illuminated by two monochromatic beams. The characteristic bound exciton peak is observed at temperatures below 200 °K. At lower temperatures a maximum around 1.3 eV (energy of the incident beam) can also be observed. The excitonic peak can be enhanced or quenched upon shining a 1.38- or 1-eV bias light respectively. The 1.3-eV peak of the TAV spectrum can be completely quenched by illuminating the sample with the 1-eV bias light, whereas the 1.38-eV bias light does not have an appreciable effect on this peak. The theoretical model suggests the presence of a band of donor level at about 1.3 eV below the conduction band and a band of acceptor level at 1 eV above the valence band.
Oscilloscope measurement of picosecond voltage pulses
Authors: Margulis W. , Laval S.
Published: February 2003

It is shown that the limited bandwidth of oscilloscopes significantly affects the measurement of picosecond voltage pulses generated with ultrafast semiconductor switches. The conductance of the devices is described by a simple model, which allow interpreting the actual time evolution of the voltage pulses.
Multiple electrode system for high power CO2 laser excitation
Authors: Harry J. E. , Saleh S. N.
Published: February 2003

A multiple electric discharge using six pairs of electrodes to obtain a uniform volume of ionized gas suitable for the excitation of a cw CO2 laser is described. Two methods of connection are investigated; parallel in which the current in adjacent discharges is in the same direction and antiparallel in which current flow in adjacent discharges is opposed. An input power density of the order of 4.18×104 W/l/atm was obtained which is of the order of twice that obtainable with a conventional axial discharge system. The results are applicable to axial excitation lasers (parallel) and transverse excitation (antiparallel).
Plasma bubble domains: A magnetic bubble analog
Authors: Boyers David G. , Tiller William A.
Published: February 2003

Results are presented on the discovery of plasma bubble domains (PBD’s), which occur as regular patterns of localized glow discharges formed under ac excitation in an atmospheric pressure inert gas based mixture confined between large-area, closely spaced, plane-parallel, dielectric-covered electrodes. These plasma bubble domains have many characteristics analogous to those of magnetic bubble domains (MBD’s): (1) Changing the applied field changes the size and the shape of the domain that forms (bubble, stripe, etc.). (2) There is a range of applied fields over which a bubble domain exhibits a corresponding range of stable diameters. (3) Bubble domains are bistable. Whereas MBD’s are used in computer memory devices, PBD’s are most likely to be used in computer display devices. ials; electrodes; surface coatings; electric fields; configuration;
Evidence for hot-electron injection across p-GaP/electrolyte junctions
Authors: Turner John A. , Nozik Arthur J.
Published: February 2003

Evidence has been obtained for hot-electron injection from illuminated p-GaP photocathodes into nonaqueous electrolyte containing anthracene as the electron acceptor. The position of the conduction-band edge at the electrolyte interface has been unequivocally established from Mott– Schottky plots in the dark and under illumination; no band-edge movement occurs during the experiment. The observed supraband-edge reduction of anthracene occurs with a hot-electron energy of 0.9 eV.
Generation of single-mode picosecond pulses by injection locking of an AlGaAs semiconductor laser
Authors: Andersson T. , Lundqvist S. , Eng S. T.
Published: February 2003

We report on the generation of picosecond single-mode optical pulses with 1-GHz repetition rate. Single-mode operation is obtained by injection locking a modulated multimode buried optical guide laser with a single-mode channel substrate planar master laser. The power ratio of the dominant mode to the total emitted power is improved from less than 0.07 without to more than 0.9 with injection locking. Detection is performed with an autocorrelator using second-harmonic generation in a nonlinear crystal. A pulsewidth of 58 ps is obtained assuming a Gaussian pulse shape. Moreover, the substructure of spikes caused by multimode operation is strongly suppressed when the laser is injection locked.
Facet degradation and passivation of InGaAsP/InP lasers
Authors: Fukuda M. , Takahei K. , Iwane G. , Ikegami T.
Published: February 2003

Formation of oxide on mirror facets was observed by Auger electron spectroscopy in InGaAsP/ InP buried heterostructure lasers. The oxide on the mirror facets caused increase of threshold current and leakage current, and decrease of differential quantum efficiency. Such phenomena were observed under nonlasing high current density operation as well as under high optical output power operation. The degradation of lasers due to the mirror facet oxidation is shown to be suppressed by coating the mirror facet with Al2O3.
Study of the electronic structure of amorphous silicon using reverse-recovery techniques
Authors: Silver Marvin , Giles N. C. , Snow Eric , Shaw M. P. , Cannella V. , Adler David
Published: February 2003

We have carried out a series of reverse-recovery experiments on pin diodes of amorphous-Si:F:H of thicknesses up to 3.5 μm under pulsed high-level injection conditions. No evidence for charge storage was obtained. Our results indicate that the room-temperature band mobility for electrons moving near the mobility edge in a-Si:F:H is larger than 100 cm2/Vs. In addition, our data suggest that either an intrinsic or induced gap exists in the density of localized states below the conduction-band mobility edge, in surprising contrast with conclusions deduced from a variety of recent experiments.
Shear piezoelectricity in ethylene dichloride solution of poly-γ-methyl-L-glutamate
Authors: Fukada Eiichi , Ueda Hiroyoshi
Published: February 2003

When ultrasonic shearing stress is applied to electrically oriented α-helical molecules of poly-γ-methyl-L-glutamate (PMG) in solution, electric potential is observed in the direction perpendicular to the plane of the shear stress. The apparent shear pizeoelectric coefficient is about 1×10−9 V m2/N and five orders of magnitude as small as that for the oriented solid PMG. The effect is not observed for PMG solutions with non-α-helical solvents such as dichloroacetic acid, which suggest that the effect is due to shear piezoelectricity in α-helical polypeptides.
Optical bistability in nematic films utilizing self-focusing of light
Authors: Khoo I. C.
Published: February 2003

Optical bistable operation in the transmission characteristics of a nematic liquid crystal film is observed. The mechanism for the bistability is the self-focusing of light via optically induced molecular reorientations. The process occurs at very modest cw input laser power on the order of 0.3 W (intensity of ∼500 W/cm2) in a 60-μm-thick sample.
Thermal stability of platinum silicide contacts to silicon with molybdenum as final metallization
Authors: Cohen S. S. , Piacente P. A. , Brown D. M.
Published: February 2003

We have studied molybdenum as a final metallization level over platinum silicide contacts for very large scale integration (VLSI) application. Molybdenum has been chosen owing to its good metallurgical and electrical properties. The Mo/PtSi contacts to n+ and p+ silicon have been found to be stable to heat treatments up to 700 °C for several hours. Values of the specific contact resistance range from ∼5 Ω μm2 for a 60-min heat treatment at 400 °C to ∼40–80 Ω μm2 for a 120-min treatment at 700 °C.
Thin-film CaF2 inorganic electron resist and optical-read storage medium
Authors: Harrison T. R. , Mankiewich P. M. , Dayem A. H.
Published: February 2003

Polished silicon substrates were e-gun deposited with 100-nm films of CaF2 in a molecular beam epitaxy vacuum station. Measurements of this material system reveal a factor of 35 reduction in reflectivity for films exposed to electron irradiation. Exposure is accomplished by simply viewing the desired area using a 3-kV Auger electron microprobe. It is further reported that this exposed inorganic material can be developed (selectively washed away) in H2O. In addition, both over and under exposures have been observed. Optimum electron exposure dose has been determined to be 0.1–0.2 C/cm2.
Continuous wave high-power, high-temperature semiconductor laser phase-locked arrays
Authors: Scifres D. R. , Burnham R. D. , Streifer W.
Published: February 2003

Continuous wave GaAlAs semiconductor laser arrays are reported to emit 585-mW/facet cw optical output power at room temperature. The lasers operate over 100 °C with output powers in excess of 200 mW/facet cw. Laser thresholds are as low as 130 mA, differential quantum efficiencies exceed 60% for some devices, and very high total power conversion efficiencies of over 20% are observed.
High-power individually addressable monolithic array of constricted double heterojunction large-optical-cavity lasers
Authors: Botez D. , Connolly J. C. , Gilbert D. B. , Harvey M. G. , Ettenberg M.
Published: February 2003

Ten-unit individually addressable arrays of constricted double heterojunction large-optical-cavity (CDH-LOC) diode lasers have been realized by one-step liquid phase epitaxy over channeled substrates, and by bonding to ten-electrode BeO submounts. Maximum overall powers of 320 mW in cw operation and 3.6 W in pulsed operation (100 ns, 1 kHz) have been achieved. Device interspacing is 150 μm and thermal crosstalk is of little significance. The devices’ lasing thresholds, near-field patterns, and power capabilities are highly uniform across the array. This is the first report of a monolithic diode laser array capable of use in multichannel optical recording.
Photoluminescence of H2S in a rare-gas matrix
Authors: Scott W. , Walker W. C.
Published: February 2003

Photoluminescence emission and excitation spectra of H2S doped into a solid Kr matrix are presented. The results are interpreted in terms of the formation of a KrS excimer formed by photodissociation of the H2S to produce S(1S) and H2. A photodissociation threshold of 7.5 eV (1675 Å) corresponding to the first vibrationless electronic transition of H2S was observed for the production of S(1S). The results are compared to similar spectra for Kr:OCS observed previously.
Thermal annealing of microcracks produced by backside laser irradiation of silicon
Authors: Eggermont G. E. J. , Gee S. A. , van Kessel C. G. M. , Falster R. J. , Gibbons J. F.
Published: February 2003

Using a cleavage cross-section technique in combination with Nomarski and scanning electron microscopy, the irradiation of silicon wafer backsides with neodymium: yttrium aluminum garnet laser pulses with energy densities of 20 J/cm is shown to lead to the formation of microcracks in the silicon up to a depth of 20–40 μm. The microcracks are shown to heal during a temperature cycle at 1050 °C. Preferentially etching the cleaved cross-section surfaces shows the occurrence of dislocations, and the healing of the microcracks is suggested to be the mechanism for the formation of these dislocations, possibly in the form of low angle boundaries. The observed effects and interpretation offer an explanation for the wafer fracture strength behavior exhibited by laser backside damaged silicon wafers.
Low threshold InGaAsP terrace mass transport laser on semi-insulating substrate
Authors: Chen T. R. , Chiu L. C. , Yu K. L. , Koren U. , Hasson A. , Margalit S. , Yariv A.
Published: February 2003

Very low threshold InGaAsP terrace lasers on semi-insulating (SI) InP substrate have been fabricated using the mass transport technique. The fabrication process involves a single-step liquid phase epitaxial (LPE) growth followed by a mass transport of InP at ∼675 °C in the presence of an InP cover wafer. Lasers operating in the fundamental transverse mode with smooth far-field patterns and threshold currents as low as 9.5 mA have been obtained.