bluuebunny/crossref_metadata_2025 huggingface dataset:
An insulated-gate charge transfer device on InP
Authors: Lile D. L. , Collins D. A.
Published: February 2003

A three-phase, single-cell insulated-gate charge-coupled device on p-type InP is reported which demonstrates the potential of this material for charge transfer applications. Charge transfer efficiencies ≳99.5% have been observed for devices operating at clock rates up to 50 MHz.
Ion-beam shadow printing through thin silicon foils using channeling
Authors: Csepregi L. , Iberl F. , Eichinger P.
Published: February 2003

A masking concept for ion-beam shadow printing is described. Resist layers have been exposed through thin single-crystal silicon foils in the channeling direction, using a collimated helium beam with an initial energy of 300–2000 keV. The masking technique employs the dechanneling effect of a thin metal layer as well as the difference in energy loss for random and for channeling directions. The method is suitable for the replication of high-resolution structures using proximity exposure.
Ion-beam-induced epitaxy in the Pd/Si system
Authors: Ishiwara Hiroshi , Kuzuta Nobuyuki
Published: February 2003

Epitaxial growth of Pd2Si has been observed at room temperature by implanting energetic Ar ions through a Pd film on a (111) Si substrate. It was found from ion channeling and backscattering measurements that the ion-beam-induced growth was initiated at the Pd-Si interface and the thickness of the grown layer increased with ion dose even after the surface region of the Si substrate had been completely amorphized by Ar ion bombardment. A uniform epitaxial Pd2Si film 120 nm thick was obtained by implanting 200-keV Ar ions to doses higher than 5×1016 cm−2, for which the channeling minimum yield of 1.5-MeV He ions was about 0.1 of the random yield, and diffraction patterns in transmission electron microscopy showed strong single-crystalline spots. Some additional experiments have also been performed to investigate the growth mechanism.
Two-dimensional focusing holographic grating coupler
Authors: Heitmann D. , Pole R. V.
Published: February 2003

Two-dimensional focusing grating couplers have been produced using holographic interferometry with freely propagating wave fronts. Theoretical considerations lead to an optimized holographic arrangement. Experimental grating couplers with 2.2-μm focus-spot diameter have been achieved.
Steam thermal SiO2: Preparation and Raman characterization of free-standing films
Authors: Mikkelsen J. C. , Galeener F. L.
Published: February 2003

Free-standing thick films of thermally grown SiO2 have been prepared by pressure steam oxidation of Si at 650–1000 °C. Characterization of these films by Raman spectroscopy reveals no important structural differences from appropriately annealed bulk fused silica, except for the different water content, which is readily determined. We show that no features of the Raman spectra can be associated with growth-induced structural anisotropy or the structures that give rise to such metal-oxide-semiconductor defects as Qss.
Photoluminescence of lattice-matched In1−xGaxP1−yAsy layers on GaAs
Authors: Kyuragi H. , Suzuki A. , Matsumura S. , Matsunami H.
Published: February 2003

Photoluminescence of undoped n-type and Zn-doped p-type lattice-matched liquid-phase epitaxy (LPE) In1−xGaxP1−yAsy layers on (100) GaAs has been studied at 4.2–290 K. Temperature dependences of the peak photon energy and the half-width of the band-to-band transitions of the undoped layer were measured. The half-width agreed well with the theoretical value of 1.8 kT. The band gap determined from the peak photon energy varied as 1.987−(7.284×10−4 T2)/(T+344) eV. Photoluminescence of the p-type layer showed the band-edge peak and another emission peak due to the recombination through Zn acceptors at 37–63 meV lower photon energy.
Metal-insulator-semiconductor solar cells using amorphous Si:F:H alloys
Authors: Madan A. , McGill J. , Czubatyj W. , Yang J. , Ovshinsky S. R.
Published: February 2003

Metal-insulator-semiconductor-type photovoltaic devices using amorphous Si:F:H alloys have been fabricated. Conversion efficiencies of up to 6.3% under AM:1 illumination have been observed. These represent the highest efficiencies yet reported for amorphous thin-film solar cells.
Anomalous thermal expansion in amorphous Fe78Mo2B20
Authors: Tyagi Somdev , Steinberg Jerry , Lord Arthur E.
Published: February 2003

The amorphous Fe78Mo2B20 alloy exhibits anomalous thermal expansion upon annealing. Two transitions in the magnetic structure are observed at approximately 210 and 315 °C. This is possibly because of the phase separation that takes place in the crystallization sequence in the amorphous alloys.
Multiphonon relaxation rates from delayed laser emission in Nd-YAG crystals
Authors: Ramsey J. M. , Whitten W. B.
Published: February 2003

Delayed laser emission from a ND-YAG oscillator pumped by a 532-nm 50-ns pulse is interpreted in terms of multiphonon relaxation from the pumped levels to the upper laser level. The relaxation rate constant, (1.6±0.2)×106 s−1, is in good agreement with previous results obtained from the fluorescence rise time.
Homoepitaxial molecular beam growth of InP on thermally cleaned {100} oriented substrates
Authors: Roberts J. S. , Dawson P. , Scott G. B.
Published: February 2003

{100} oriented homoepitaxial films of InP have been deposited by molecular beam epitaxy using the dimer species P2. The starting surface for epitaxial growth was established by thermally cleaning the substrate in a P2 flux in contrast to the generally adopted technique of argon-ion sputtering followed by annealing. Both undoped and Sn-doped InP layers deposited within the temperature range 770–700 K exhibited 77-K mobilities consistent with a compensation ratio ∼ 2. The 77-K external photoluminescence yield of 0.6-μm-thick layers was comparable with that from 2-μm-thick molecular beam epitaxial films of the same free-electron concentrations but grown on surfaces cleaned by argon-ion sputtering.
Reversible optical recording in trilayer structures
Authors: Bell Alan E. , Spong Fred W.
Published: February 2003

The reversible optical recording of FM video signals is reported. The recording medium is based upon the amorphous-to-crystalline phase transition of pure tellurium, incorporated into a trilayer antireflection structure. In excess of 50 record/erase cycles have been demonstrated, with no significant degradation in playback signal quality or erasability. The irreversible process of ablative pit formation (hole opening) has been inhibited by the use of a silicon dioxide capping layer.
A Josephson dc-powered latch
Authors: Dhong Sang H. , Gheewala Tushar
Published: February 2003

A new dc-powered Josephson latch has been designed and experimentally investigated.A latch is defined as a digital circuit in which information can be stored in a controlled manner. The latch we describe here consists of a nonlatching interferometer in series with a superconducting storage loop containing a second interferometer. Within the nominal operating region the latch has only two stable states and it does not display the problem of falling into a stable faulty state, in which the latch would respond to neither of its inputs (SET or RESET). Computer simulations using nominal 2.5-μm technology-device models indicate that the latch changes state in about 80 ps.
Arsenic-implanted Si layers annealed using a cw Xe arc lamp
Authors: Drowley C. , Hu C.
Published: February 2003

Arsenic implanted layers in 〈100〉 silicon are annealed using a cw Xe arc lamp. The layers, made amorphous by the implantation, crystallize with the same orientation as the substrate. The crystallization appears to follow the solid-phase epitaxial growth model. Approximately 67% of the dopant is activated in the Xe-lamp-annealed samples, compared to ∼80% in samples annealed at 900 °C for 30 min.
The origin and nature of silicon band-gap states at the Si/SiO2 interface
Authors: Singh J. , Madhukar A.
Published: February 2003

We present argumenrs for the origin and nature of the U-shaped density of interface states found at the Si/SiO2 interface and at other interfaces between nonlattice-matched systems. These states are proposed to be band-tail states induced by the presence of a thin, disordered semiconductor layer at the interface. They are Anderson localized states and not due to highly localized defects (extending over a few atomic sites) which may induce additional specific structure. Statistical arguments are combined with a variational principle to show that the U-shaped density of interface states has a universal energy dependence, the width of these band tails being determined by the extent of disorder present at the interface. Comparison of the theoretical results with experimental observations is encouraging.
A surface-acoustic wave/metal-oxide-silicon field-effect transistor memory correlator
Authors: Smythe D. L. , Ralston R. W.
Published: February 2003

An array of metal-oxide-silicon field-effect transistors has been integrated with a surface-acoustic wave (SAW) delay line in a hybrid gap-coupled structure to produce a SAW-programmable memory correlator. This device allows analog-analog correlation of SAW input signals of 40-MHz bandwidth and 3.5-μs duration. Operation with a 1.8-μs-long rectangular pulse at a carrier frequency of 100 MHz yields a peak correlation output of about -46 dBm.
1.55-μm narrow planar stripe InGaAsP lasers with deep Zn diffusion
Authors: Kawaguchi Hitoshi , Takahei Kenichiro , Suzuki Yoshio , Iwane Genzo
Published: February 2003

Narrow planar stripe InGaAsP lasers with deep Zn diffusion are experimentally demonstrated at a wavelength of around 1.55 μm. Improved current confinement was achieved by the deep Zn diffusion structure, and low-threshold lasers with a 3-μm stripe were obtained. Measured far-field patterns indicate that the lateral transverse mode is mainly determined by antiguiding. Narrow stripe lasers of this type show a tendency to operate in a multilongitudinal mode.
Ultrasonic detection and sizing of two-dimensional defects at long wavelengths
Authors: Fortunko C. M.
Published: February 2003

An ultrasonic technique is described for detecting and sizing of two-dimensional defects. The technique is particularly suitable for detecting two-dimensional defects in certain butt-weldments which cannot be fully inspected by conventional radiographic and ultrasonic methods. Use is made of noncontact, electromagnetic-acoustic transducers to excite and detect shear horizontal (SH) wave probing signals where wavelength is long compared to the defect depth dimensions. The new technique is demonstrated in conjunction with a weld fatigue testing investigation in which it is used to detect natural weld defects and to monitor crack initiation and growth under tension-tension fatigue loading. An experimental calibration curve is given for sizing two-dimensional surface defects, and the experimental results are explained in terms of a reciprocity relationship evaluated in the elastostatic limit.
Generation of field-sensitive interface states
Authors: Crowley John L. , Stultz Timothy J. , Ichiki Stephen K.
Published: February 2003

We have observed the generation of interface states in SiO2 metal oxide semiconductor (MOS) capacitators that are field- and time-dependent as well as thermally activated. A strong correlation has been found between these metastable interface states and the radiation hardness of the MOS devices. The number of interface states generated is linearly dependent on the applied field with a threshold field for occurrence. There is a t1/4 time dependence for interface-state generation. The generation of these field-sensitive interface states is thermally activated with a field-dependent activation energy.
Absorption spectra of garnet films between 1.0 and 1.8 μm by guided-wave optical spectroscopy
Authors: Olivier Michel , Peuzin Jean-Claude , Danel Jean-Sébastien , Challeton Didier
Published: February 2003

Continuous recording of the absorption spectra of thin films by an optical guided-wave technique is demonstrated. In the case of a garnet thin film of compositoin (YSmLuCa)3(FeGe)5O12 it is shown that the near-infrared Sm3+ absorption bands are clearly visible in contrast with conventional transmission measurement. Comparison with the absorption spectrum of bulk Sm3Fe5O12 garnet allows the determination of an Sm concentration in the film.
Carrier collection efficiency of a-SiHx Schottky-barrier solar cells
Authors: Gutkowicz-Krusin D. , Wronski C. R. , Tiedje T.
Published: February 2003

A diffusion model for the collection efficiency of a-SiHx Schottky-barrier solar cells is found to be in excellent agreement with experimental data. This model accounts for the poor short-wavelength response of these devices and suggests a way for improving their performance.
Slip dislocation formation during cw laser annealing of silicon
Authors: Baumgart H. , Phillipp F. , Rozgonyi G. A. , Gösele U.
Published: February 2003

High-voltage electron microscopy (HVEM) has been used for the investigation of the defect structure in cw laser-annealed silicon. We report for the first time a (HVEM) analysis of the formation processes involved in the nucleation and glide of slip dislocations during epitaxial regrowth by cw laser annealing of ion-implantation damaged silicon layers. Based on the combined optical and HVEM observations a model of the dislocation generation and glide processes is presented.
Scanned electron beam annealing of boron-implanted diodes
Authors: Yep T. O. , Fulks R. T. , Powell R. A.
Published: February 2003

Successful annealing of p+n diode arrays fabricated by ion implantation of 11B (50 keV, 1×1014 cm−2) into Si (100) has been performed using a broadly rastered, low-resolution (0.25 in. diameter) electron beam. A complete 2 in. wafer could be uniformly annealed in ≃20 sec with electrical activation ≃75% and small dopant redistribution (∼450 Å). Annealing resulted in p+n junctions characterized by low reverse current (?4 nA/cm2 at 5-V reverse bias) and high carrier lifetime (≳80 μsec) over the entire 2 in. wafer. Based on the electrical characteristics of the diodes, we estimate that the electron beam anneal was able to successfully reorder the substrate and remove ion implantation damage near the p+n junction.
Infrared detection using acousto-optic interaction with thermally induced grating in optical waveguides
Authors: Black T. D. , Komotskii V. A.
Published: February 2003

A new method of detecting infrared radiation which allows direct coupling into integrated optics is presented. The method utilized the coherent interaction of surface acoustic waves and a thermally induced grating in an optical waveguide. The sensitivity was found experimentally to be approximately 1.5×10−4 J/cm2 for 1-msec CO2 laser pulses. Analysis indicated that the sensitivity could be improved by orders of magnitude, since the waveguide film absorbed less than 0.2% of the radiation and that rise times of the order of several nanoseconds should be possible. The method is not limited to infrared radiation; any mechanism which can change the index of refraction could, in principle, be used.
Intracavity loss modulation of GaInAsP diode lasers
Authors: Tsang D. Z. , Walpole J. N. , Groves S. H. , Hsieh J. J. , Donnelly J. P.
Published: February 2003

Diode lasers with an intracavity electroabsorption modulator have been fabricated in the GaInAsP/InP material system. The additional absorption loss produced by operating the modulator near maximum reverse bias increased the laser threshold by a factor of as much as 2.9 relative to the threshold with the modulator open circuited. Large depth of modulation of the laser output at frequencies up to 2.5 GHz, the measurement system limit, has been achieved by application of a microwave signal to the modulator.
Long-pulse intense ion source
Authors: Lockner Thomas R.
Published: February 2003

A long-pulse intense ion source has been developed using a modification of the reflex triode. Pulse lengths up to 40 ns have been obtained at a voltage of 450 kV, and more than 2×1014 protons have been generated in a single pulse. Repetitive operation of the accelerator has also been demonstrated. The maximum pulse length is presently limited only by insulator flashover of the diode.
Chromium gettering in GaAs by oxygen implantation
Authors: Favennec P. N. , Gauneau M. , L’Haridon H. , Deveaud B. , Evans C. A. , Blattner R. J.
Published: February 2003

Oxygen-ion implantation has been performed in chromium-doped GaAs substrates. Oxygen chromium profiles were measured by SIMS. Implanted oxygen profiles are observed for the first time. The chromium distribution, in annealed samples, shows an accumulation. This accumulation is shown to depend on the implanted ion and on the nature and concentration of the metallic impurity in the substrate. Thus one can no longer expect to analyze the contribution of any single impurity without taking into account other incorporated impurities.
Low-frequency intensity fluctuation in laser diodes with external optical feedback
Authors: Fujiwara Masahiko , Kubota Keiichi , Lang Roy
Published: February 2003

Enhanced intensity fluctuations, in particular the low-freqeuncy fluctuation (LFF) component, which appear in a semiconductor laser-diode (LD) output with external optical feedback, can have seriously adverse effects in practical applications when they fall within the signal bandwidth. Experiments have been carried out to determine the mechanism of the LFF enhancement, and a simple relationship between its peak frequency f0 and the basic parameters characterizing an LD with an external reflector have been established. The resuts are in qualitative agreement with the prediction based on a compound cavity laser model.
Device characteristics of (AlGa)As multiquantum-well heterostructure lasers grown by molecular beam epitaxy
Authors: Tsang W. T.
Published: February 2003

A study has been made on the device characteristics of multiquantum well (MQW) lasers grown by molecular beam epitaxy. These wafers have different numbers of wells and different well and barrier thicknesses. The results show that averaged threshold current densities Jth as low as the lowest Jth (800 A/cm2) obtained for standard double-heterostructure lasers with approximately the same AlAs composition in the cladding layers were obtained in spite of the reduced optical confinement factor Γ and the increased number of interfaces. Significant beam width reduction in the direction perpendicular to the jucntion plane was obtained. Half-power full-width as narrow as 15° was measured for some MQW wafers. For some MQW wafers the lasers fabricated generally have a characteristic temperature T0≳215 °C in the temperature range of 10–130 °C. The present study also shows that the device characteristics of the MQW lasers depend quite significantly on the detailed designs of the multilayer structure that composes the active region.
Electro-wetting displays
Authors: Beni G. , Hackwood S.
Published: February 2003

We show that a novel effect, electro wetting, can be the basis of passive displays which (i) switch reversibly from transparent to white, (ii) have fast response time (<1.0 ms),and (iii) can be operated with low voltages (<1.0 V) and low power consumption (<1.0 mW/cm2). We derive the operating parameters and report experiments demonstrating the concept of electro-wetting displays.
Photon correlation spectroscopic analysis of a natural electret material: Carnauba wax
Authors: Barbosa G. A. , Russi R. , Pires A. S. T. , Mesquita O. N.
Published: February 2003

For the first time, photon correlation spectroscopy is applied to the study of an electret material. We show that the average self-diffusion parameter of Carnauba wax in liquid phase, from 85 to 170 °C can be written as D=D0+A exp[−ΔE/k(T−T0)], where D0=1.6×10−10 and A=20×10−10 cm2/sec, ΔE=82 cm−1 and T0=68 °C
Photoluminescence technique for the determination of minority-carrier diffusion length in GaAs grown by molecular beam epitaxy
Authors: Duggan G. , Scott G. B. , Foxon C. T. , Harris J. J.
Published: February 2003

Using the minority-carrier diffusion length and surface and interface recombination velocities as adjustable parameters, we have fitted a theoretical expression to the observed photoluminescence response of stepped thickness layers of GaAs prepared by molecular beam epitaxy. The minority-carrier diffusion lengths so extracted are in good agreement with those obtained by other techniques.
Dynamics of laser-induced vaporization for ultrafast deposition of amorphous silicon films
Authors: Hanabusa M. , Suzuki M. , Nishigaki S.
Published: February 2003

Atomic vapor produced by a frequency-doubled, pulsed Nd:YAG laser with its beam focused on a silicon plate has been used to deposit amorphous silicon films on substrate at room temperature. Time-resolved measurements on the emission lines from vaporized Si show that the laser-irradiated surface is kept at temperatures high enough to maintain a significant amount of vaporization for approximately 40 ns after the 7-ns laser pulse. Since intense pulsed atomic beams are used, the silicon films grow at high speed in excess of 106 Å/s.
Oxygen sensing by electrochemical pumping
Authors: Hetrick Robert E. , Fate W. A. , Vassell W. C.
Published: February 2003

An oxygen pumping structure using ZrO2 electrochemical cells is described for measuring the percentage of O2 in a high-temperature gaseous environment. The device output is linearly proportional to the O2 percentage, has a weak dependence on temperature, and does not require a reference atmosphere.
Initial observations of optical injection locking of GaAs metal semiconductor field effect transistor oscillators
Authors: Salles A. A. , Forrest J. R.
Published: February 2003

An experiment is described in which the output of a GaAlAs laser, modulated at 2.345 GHz, was used to optically injection lock a GaAs metal semiconductor field effect transistor oscillator. A substantial reduction of the FM noise of the field effect transistor oscillator, associated with locking to the more stable modulation signal applied to the laser, was obtained. The locking range obtained was 5 MHz, but possibilities for considerably increasing this are suggested.
Effects of inert gas dilution of silane on plasma-deposited a-Si:H films
Authors: Knights J. C. , Lujan R. A. , Rosenblum M. P. , Street R. A. , Bieglesen D. K. , Reimer J. A.
Published: February 2003

Electrical, optical, and structural characterization of hydrogenated amorphous silicon films plasma-deposited from mixtures of SiH4 with different inert-gas diluents reveals substantial differences in a number of properties. A general trend of increasing defect density with atomic weight of the inert gas is observed. Of specific interest to device applications is the observation that high deposition rates can be achieved concurrently with low defect densities when helium is used as a deluent.
Control of melt-front velocity during pulsed laser annealing
Authors: Wood R. F. , Giles G. E.
Published: February 2003

The high recrystallization velocities attained in the pulsed-laser annealing of ion-implanted semiconductors lead to remarkable nonequilibrium segregation effects. Detailed studies of these effects and the physical mechanisms which underlie them require control of the recrystallization velocity over a wide range. In this letter, the results of computer calculations are used to demonstrate three methods for controlling the regrowth velocity in Si and to indicate the range of velocities which may be expected by the methods.
Activation analysis of forward-biased CdS-electrolyte diode
Authors: Vainas B. , Hodes G. , Manassen J. , Cahen D.
Published: February 2003

The activation energies and the preexponential factors in the expression for the forward current at the CdS-electrolyte junction were determined as a function of the applied bias. It is suggested that the observed dependence of the preexponential factor on the activation energy can be explained by changes in tunneling probability due to variations in the activation energy.
Magnetic bubbles with different wall states in a (110) oriented garnet film
Authors: Konishi S. , Engemann J. , Heidmann J. , Hibiya T.
Published: February 2003

In a (110) oriented (YTmBi)3(FeGa)5O12 garnet film with orthorhombic anisotropy, bubbles with different wall states were carefully studied using the bubble rocking method. Eight different bubble states have been identified, each belonging to a family of either large or small bubbles and coexisting at the same bias field. Each family is represented by elliptical S = 1,0,−1 and circular S = 0 bubbles. All bubbles have roughly the same mobility, whereas the static collapse fields differ as much as 6.1 Oe. Under all experimental conditions so far, we observed no conversion from small to large bubbles or vice versa, which indicates a remarkable stability of the two bubble families observed.
Picosecond microwave pulse generation
Authors: Mourou Gerard , Stancampiano Charles V. , Blumenthal Daniel
Published: February 2003

Picosecond duration X-band microwave pulses have been generated using a laser-activated photoconductive switch. These pulses have been used to observe the microwave reflection from optically excited germanium. The reflection measurements indicate that the microwave pulse has a full width at half-maximum of 50 ps and is synchronized with picosecond precision to the laser pulse. A high-resolution radar experiment is also reported.
Voltage-controlled photoetching of GaAs
Authors: Hoffmann H. J. , Woodall J. M. , Chappell T. I.
Published: February 2003

The effects of optically generated minority-carrier current on the etching behavior of n-type GaAs in 1-M KOH aqueous solution were studied. It was observed that the etch rate depends on the minority-carrier current flow through the interface, which is controlled by the bias voltage. The etch rate is considerably reduced under open-circuit conditions as compared to short-circuit conditions. This effect simulates a self-limiting photoetching process for the thickness trimming of thin films, which is necessary for several device applications.
Emission pulse delay in fiber laser plate and its application in optical logic operation
Authors: Seko Atsuya , Murakami Kazuyuki
Published: February 2003

We originally propose and demonstrate optical parallel logic operations such as level slicing and the NOT and Exclusive OR (EXOR) operations using emission-pulse time delay in a fiber laser plate and gating technique. These operations are essential for the optical digitial computations.
Transient and noise characteristics of quantum-well heterostructure lasers
Authors: Anderson E. R. , Vojak B. A. , Holonyak N. , Stillman G. E. , Coleman J. J. , Dapkus P. D.
Published: February 2003

The transient and noise characteristics of single and multiple-quantum-well heterostructure lasers grown by metalorganic-chemical vapor depostion are investigated. In pulsed operation these lasers do not exhibit damped relaxation oscillations and under dc excitation the quantum shot noise resonance is much less than that of standard double heterostructure lasers of comparable stripe widths.
Laser-induced diffusion by irradiation of silicon dipped into an organic solution of the dopant
Authors: Stuck R. , Fogarassy E. , Muller J. C. , Hodeau M. , Wattiaux A. , Siffert P.
Published: February 2003

A new method for preparation of p-n junctions is presented. It consists in dipping the silicon to be doped into an organic liquid containing the dopant and irradiating its surface through the liquid with a high-energy pulsed ruby laser. It is shown that by this treatment the dopant is driven into the crystal and that abrupt junctions with high doping levels can be realized. Using this simple technique, solar cells with AM1 efficiencies above 13% can be prepared.
Noise temperature contours for high-sensitivity SQUID’s
Authors: Davidson A.
Published: February 2003

A simple expression is developed for the noise temperature TN of SQUID amplifiers. The expression is in terms of equivalent current and voltage noise generators in the input circuit, and is shown to contain the spectral energy resolution, which is the currently accepted figure of merit for SQUID’s. It is also shown that a SQUID optimized for the best energy resolution is not necessarily optimized for the lowest noise temperature.
Waveguide electro-optic polarization transformer
Authors: Alferness R. C. , Buhl L. L.
Published: February 2003

We propose and demonstrate a novel waveguide electro-optic device which is capable of performing general polarization transformations under electrical control. The device, made with a Ti-diffused lithium niobate waveguide, combines in a unique optical circuit an electro-optic (e/o) TE⇄TM mode converter and two e/o phase shifters to provide general polarization transformations. This is the first report of a waveguide e/o device capable of performing arbitrary polarization transformations. As a linear rotator the device exhibits a rotation rate of 15°/V with better than 23-dB fidelity. We also demonstrate transformation between circular and linear polarization.
Two-dimensional coupled differential equations for degenerate four-wave mixing
Authors: Wilson Tony , Solymar Laszlo
Published: February 2003

Coupled differential equations which include the effect of nonplanar beams and of nonuniform amplitude distributions are derived for the amplitudes of the four waves. The method is illustrated by two examples for the case when the pump beams are much stronger than the object and image beams.
Transient annealing of arsenic-implanted silicon using a graphite strip heater
Authors: Tsaur B.-Y. , Donnelly J. P. , Fan John C. C. , Geis M. W.
Published: February 2003

Transient annealing with a graphite strip heater has been used to accomplish solid-phase epitaxial recrystallization of amorphous layers produced in Si by implantation of 120-keV As+ ions. For doses of 5×1014 or 2×1015 cm−2, annealing at 900–1000 °C for 10 s results in electrical activation comparable to that obtained by a conventional furnace anneal at 1000 °C for 30 min, but with negligible dopant redistribution. For a dose of 1×1016 cm−2, activation is slightly less than that of furnace-annealed samples, but sheet resistance as low as 22 Ω/⧠ has been obtained by annealing at 1200 °C for 10 s. Mesa diodes fabricated on strip-heater-annealed samples exhibit good junction characteristics.
An improved technique for calculating the resolution of trochoidal electron monochromators.
Authors: Bond J. W.
Published: February 2003

Data generated by an improved method of calculating the resolution of a trochoidal monochromator is given and comparisons made with existing experimental results. An agreement to better than 5% is obtained for electron energies extending over several orders of magnitude. Evidence is given which suggests a possible explanation for the complete shape of the observed transfer functions.
Picosecond spectroscopy of bound excitons in CuCl using a synchronously operating streak camera
Authors: Fujimoto J. G. , Yee T. K. , Salour M. M.
Published: February 2003

Single crystals of CuCl at 8 K were excited with the low-intensity frequency-doubled output of an actively mode-locked R6-G dye laser. The time dependence of the bound exciton luminescence was measured directly by a synchronously operating electron-optical streak camera accumulating data at the dye laser repetition rate of 82 MHz. The instrumental time resolution was ∼25 ps. The observed bound exciton lifetime for the I line (3898 Å) was typically ∼130 ps with a formation time of less than 10 ps.
Injected-carrier induced refractive-index change in semiconductor lasers
Authors: Olsson A. , Tang C. L.
Published: February 2003

A red-shift in the diode modes with increasing optical feedback is observed in external-cavity AlxGa1−xAs injection lasers. This shift is due to a change in the refractive index in the active region resulting from a reduction in the population-inversion induced by the optical feedback. This leads to a new determination of the carrier dependence of the refractive index at the laser wavelength in the active region of semiconductor lasers independent of current-induced thermal effects.
Plasma effects in the interaction of intense light ion beams with light targets
Authors: Nardi E. , Peleg E. , Zinamon Z.
Published: February 2003

It is shown that with present-day ion beam intensities, plasma effects on the range are important in light targets. It is suggested to use the strong dependence of Kα emission on particle energy in order to observe this effect in layered targets. Neutron diagnostics in the case of deuteron beam CD2 target interaction are also considered.
Reduction in dislocation densities in the step-graded growth of InGaAs by molecular-beam epitaxy
Authors: Serrano C. M. , Chang Chin-An
Published: February 2003

The effect of varying compositional gradient on the propagation of misfit dislocations in the step-graded molecular-beam epitaxy growth of InGaAs is studied by cross-sectional transmission electron microscopy. For a composition change of 15% across the interface, the misfit dislocations are almost all confined to the interface and few defects are observed in the InGaAs layer grown. The confinement of misfit dislocations at the interfaces becomes less effective for the 5% cases; a new phenomenon of stress relieving is observed where a high-density center of inclined dislocations is formed which leaves a large neighboring area with very low density of defects.
The rate of cw laser induced solid phase epitaxial regrowth of amorphous silicon
Authors: Lietoila A. , Gold R. B. , Gibbons J. F.
Published: February 2003

The rate of cw laser induced solid phase epitaxy in self-implantation amorphized silicon has been measured by determining the dwell time required to regrow the entire amorphous layer at the center of a scanned laser beam. The measurement was performed in the annealing temperature range of 800–900 °C. The measured regrowth rates were about two orders of magnitude higher than those extrapolated from low-temperature furnace annealing data.
New relaxation peaks at liquid helium temperatures due to the motion of hydrogen in trap sites around Ti in Nb
Authors: Cannelli G. , Cantelli R. , Vertechi G.
Published: February 2003

The presence of hydrogen in niobium containing 5 at. % alloying titanium gives rise to new relaxation processes at liquid helium temperatures. The effects have been studied for two H concentrations (0.08 and 0.48 at. %), and by exciting two resonance modes of the specimen (20 and 74.5 kHz). The temperatures at which the processes occur are independent of H content and their intensities increase with increase of the H concentration. At the lower resonance frequency the peaks shift towards lower temperatures and their intensities markedly decrease. This latter behavior may be explained by a delocalized tunneling model for hydrogen trapped by Ti.
Bubble states in a contiguous disk magnetic bubble device
Authors: Konishi Susumu , Tamura Minoru
Published: February 2003

Bubble states in a contiguous disk 2-μm bubble device have been studied using the dynamic bubble collapse method. We found at least three different bubble states, and two of them, soft and hard bubbles, showed 12.4 Oe of bias field margin for dynamic bubble collapse discrimination. The bubble state stability studied for a 100-Hz drive in-plane field appears fair, suggesting that the wall encoding scheme is also possible as in the conductor drive or Permalloy bubble devices. The wall structure of these three kinds of bubbles are discussed, and appears to be S = 1/2 (hard), S = (122) (soft), and S = 1H (intermediate), all having an umbrella cap.
Line narrowing and enhanced efficiency of an HgBr laser by injection locking
Authors: Shay T. , Hanson F. , Gookin D. , Schimitschek E. J.
Published: February 2003

The results of HgBr laser injection locking experiments are presented. The output energy and spectrum of an injection locked HgBr laser has been measured versus injection wavelength. When injection locking near 502 nm, the narrow band (0.05-nm FWHM) output energy was 30% higher than the broadband HgBr laser output. The wall plug efficiency of the injection locked HgBr laser is 1.3%.
Longitudinal mode control in GaAs lasers using a three-mirror active-passive cavity
Authors: Garmire E. , Evans G. , Niesen J.
Published: February 2003

Integrated optics techniques have been used to form a three-mirror laser diode configured to form a long active cavity and a short passive cavity. The third mirror results from an abrupt etched step down to the waveguide layer of a large optical cavity heterostructure laser. We have observed predominantly single-frequency operation at current levels up to 1.5 times threshold. For certain ratios of passive-to-active cavity length, these devices operated multimode within a narrow frequency range, whereas diodes with different length ratios emit two modes widely separated in frequency.
Oxide optimization at the p-Si/aqueous electrolyte interface
Authors: Lewerenz H. J. , Lübke M. , Bachmann K. J. , Menezes S.
Published: February 2003

In this letter we report a combination of surface chemical and voltammetric treatments that optimize the stability and performance of p-Si/V2+−V3+, 4MHCl/C solar cells. The power conversion efficiency is 6.1% under 60-mW/cm2 illumination. The results of capacitance-voltage measurements and the improved solar cell properties are discussed on the basis of an electrolyte-oxide-semiconductor energy band diagram.
Longitudinal mode behavior of PbSnTe buried heterostructure lasers
Authors: Kasemset D. , Fonstad C. G.
Published: February 2003

Output spectra for narrow stripe, PbSnTe buried heterostructure laser diodes are presented and it is shown that the lasers operate in a single longitudinal mode of the fundamental transverse mode family to approximately twice threshold after which multimode operation predominates. These observations are interpreted in terms of the spectral inhomogeneity of the gain function. The small inhomogeneity arises from an intraband relaxation time of the order of 2 ps.
The nonlinear propagation constant of a surface plasmon
Authors: Sarid Dror
Published: February 2003

A surface plasmon that is excited on the interface separating a metal and a nonlinear semiconductor has a propagation constant that depends on the power carried by the plasmon. We present an analytic expression for the change in the propagation constant of the plasmon, KΔβ, as a function of the dielectric constants of the two media, the nonlinear refractive index of the semiconductor, n2,E, and the power carried by the plasmon. We define a figure of merit, P0, which is the power required for shifting the phase of the plasmon by π/2 along a distance S, (S = 1/2α, where α is the plasmon decay constant), and find the wavelength dependence of KΔβ and P0.
n-channel deep-depletion metal-oxide-semiconductor field-effect transistors fabricated in zone-melting-recrystallized polycrystalline Si films on SiO2
Authors: Tsaur B-Y. , Geis M. W. , Fan John C. C. , Silversmith D. J. , Mountain R. W.
Published: February 2003

n-channel deep-depletion mode metal-oxide-semiconductor field-effect transistors (MOSFET’s) have been fabricated in Si films prepared by zone-melting recrystallization of chemical-vapor deposited (CVD) polycrystalline Si deposited on SiO2-coated Si substrates. The transistors exhibit surface electron mobility in the range of 600–700 cm2/Vs, comparable to values for devices fabricated in single-crystal Si. Measurements of electron mobility as a function of gate bias voltage indicate that the mobility is nearly constant throughout the depth of the recrystallized Si films. Mobility of 650–700 cm2/Vs at the lower Si-SiO2 interface and subthreshold source-drain leakage current of a few pA/μm (channel width) have been measured.
Laser induced chemical vapor deposition of carbon
Authors: Leyendecker G. , Bäuerle D. , Geittner P. , Lydtin H.
Published: February 2003

Initial results on laser-induced chemical vapor deposition using the visible radiation of an Ar+ laser are presented. Due to the smaller wavelength of Ar+ laser radiation in comparison to the infrared radiation of a CO2 laser used in earlier experiments, much finer patterns could be produced. The influence of laser irradiance on the deposition rate and widths of patterns was investigated.
Absolute pressure measurements using ZrO2 electrochemical cells
Authors: Fate W. A. , Hetrick Robert E. , Vassell W. C.
Published: February 2003

An absolute pressure sensor is reported that uses electrochemical pumping of oxygen. Sensor operation uses the pressure dependence of O2 diffusion in a host gas. The device is unusual because no reference pressure or vacuum is required for absolute measurements. The main features of device operation are in agreement with calculation.
Silicide films for archival optical storage
Authors: Tu K. N. , Ahn K. Y. , Herd S. R.
Published: February 2003

We demonstrate here that bilayer films consisting of Si and transition metals with a layer thickness of 15–40 nm are promising materials for archival optical storage. They show a large optical reflectivity change before and after silicide formation, have a long lifetime at room temperature, and are nontoxic.
Sub-Doppler submillimeter spectroscopy using molecular beams
Authors: Blumberg W. A. M. , Peck D. D. , Fetterman H. R.
Published: February 2003

The use of corner-cube mounted Schottky diodes to generate tunable submillimeter laser sidebands, which have a linewidth less than 10 kHz, has recently been reported. In order to demonstrate the ultrahigh resolution of the sideband generation technique, rotational transitions with sub-Doppler linewidths have been observed in molecular beams formed by capillary arrays.
Donor-acceptor pair luminescence in Si(In,Li): Observation of the In-X center
Authors: Ziemelis U. O. , Thewalt M. L. W. , Parsons R. R.
Published: February 2003

Low-temperature photoluminescence measurements carried out in Si(In,Li) indicate that the In-X center participates as a substitutional acceptor together with the interstitial donor Li-O in donor-acceptor pair recombination, giving rise to a new series of sharp lines and a broad band characteristic of such processes. Straightforward analysis, assuming only a Coulomb interaction between otherwise isolated centers confirms that recombination involving In-X and Li-O centers separated by distances ranging from 9.7 to 25 Å is responsible for the observed sharp line structure.
Theory of deep traps at semiconductor interfaces
Authors: Allen Roland E. , Buisson Jean Pierre , Dow John D.
Published: February 2003

Impurities that are shallow donors or acceptors in bulk semiconductors can become deep traps at interfaces. For example, P on one of the Si sites at a Si/GaP interface is predicted to be a deep trap.
Trapped vortex memory cells
Authors: Uehara Shingo , Nagata Koichi
Published: February 2003

A memory cell is proposed which uses vortices in type-II superconductor thin film as information bits. In the memory cell, vortices are generated by coincident current in two superconductor lines and are read out by a Josephson junction. Preliminary experimental results on vortex generation and detection are also reported.
Activation of arsenic-implanted silicon using an incoherent light source
Authors: Powell R. A. , Yep T. O. , Fulks R. T.
Published: February 2003

We report that continuous, incoherent light from a xenon arc lamp can be used to completely activate implanted Si (100) samples (75As+:100 keV, 1×1015 cm−2) with negligible dopant redistribution and excellent uniformity (sheet resistivity variation less than ±2% over a 3-in.-diam wafer). An entire 3-in. wafer could be activated in only about 10 sec without relative motion of wafer and light beam. The extent to which implant damage was removed by the incoherent light anneal is qualitatively indicated by the carrier mobilities which were within 10% of single-crystal values.
Submicron polycrystal silicon film solar cells
Authors: Fang P. H. , Schubert C. C. , Kinnier J. H. , Pang Dawen
Published: February 2003

A silicon polycrystal thin-film solar cell with a present efficiency of 1% is reported. The process involves depositing a silicon film by electron beam evaporation on metal layers with steel as the substrate. The thickness of the p-i-n structure is about 5 μm. The grain size is of the order of several hundred angstrons. Some similarities of this submicron silicon with amorphous silicon are discussed.
Ultrafast magnetophotoconductivity of semi-insulating gallium arsenide
Authors: Moyer R. H. , Agmon P. , Koch T. L. , Yariv A.
Published: February 2003

The speed of opto-electronic switches is increased or decreased by the application of a magnetic field. This is achieved by inducing a carrier drift toward or away from the semiconductor surface, resulting in the enhancement or suppression of surface recombination. We establish that surface recombination plays a major role in determining the speed of the opto-electronic switch.
Observation of grain boundary hydrogen in polycrystalline silicon with Fourier transform infrared spectroscopy
Authors: Ginley D. S. , Haaland D. M.
Published: February 2003

Fourier transform infrared spectroscopy has been applied to the study of polycrystalline silicon samples previously exposed to rf- and dc-induced hydrogen plasmas. The first direct observation of hydrogen incorporated in the grain boundaries has been made. Peaks attributable to surface hydrogen have also been observed. The techniques developed show considerable utility in probing the very small numbers of impurity atoms in grain boundaries.
Isoelectronic scaling of recombination lasers to higher ion stages and shorter wavelengths
Authors: Silfvast W. T. , Szeto L. H. , Wood O. R.
Published: February 2003

Laser action in the visible and ultraviolet (at wavelengths as short as 298 nm) in the higher ionization stages of a number of metal vapors has been produced by a population inversion mechanism based on segmented plasma excitation and recombination. Many of the transitions have never been observed in laser action before by any excitation means and a number of the oscillating transitions in silver, cadmium, and indium form isoelectronic sequences.
GaAs-oxide interface states: A gigantic photoionization effect and its implications to the origin of these states
Authors: Lagowski J. , Walukiewicz W. , Kazior T. E. , Gatos H. C. , Siejka J.
Published: February 2003

Gigantic photoionization was discovered on GaAs-oxide interfaces leading to the discharge of deep surface states with rates exceeding 103 times those of photoionization transitions to the conduction band. It exhibits a peak similar to acceptor-donor transitions and is explained as due to energy transfer from photo-excited donor-acceptor pairs to deep surface states. This new process indicates the presence of significant concentrations of shallow donor and acceptor levels not recognized in previous interface models.
Void formation in annealed proton-bombarded GaAs
Authors: Snyman H. C. , Neethling J. H. , Vermaak J. S.
Published: February 2003

Radiation damage in GaAs bombarded to a dose of 1017 protons cm−2 at 300 keV is directly observable by cross-sectional transmission electron microscopy as a dark diffuse structure. The densest region of this damage lies at the depth predicted by the Lindhard-Scharff-Schiott theory for proton penetration. During anneal for 15 min at 800–1000 °C the crystal recovers with the formation of dislocation networks interspersed with voids. The voids take on the form of dodecahedrons and produce a swelling of 2.5% at the peak of the damage distribution for samples annealed at 1000 °C.
Low-threshold 1.3-μm GaInAsP/InP buried heterostructure lasers by liquid phase epitaxy and metalorganic chemical vapor deposition
Authors: Ng Willie , Hong C. S. , Manasevit H. , Dapkus P. D.
Published: February 2003

1.3μm GaInAsP/InP buried heterostructure lasers were successfully fabricated by using a hybrid combination of liquid phase epitaxy (LPE) and metalorganic chemical vapor deposition (MO-CVD). Definite advantages were found in the use of MO-CVD for the overgrowth of the optical and current confining layers. Excellent optical linearity up to two times the threshold current, as well as low-threshold current (57 mA), were obtained during cw operation at room temperature. A single longitudinal mode was observed at ∼1.11 times the threshold current.