bluuebunny/crossref_metadata_2025 huggingface dataset:
SAW resonators using rf-sputtered ZnO films on glass substrates
Authors: Ono Shusuke , Yamazaki Osamu , Ohji Kenzo , Wasa Kiyotaka , Hayakawa Shigeru
Published: February 2003

SAW resonators have been fabricated from reflection strip arrays of ZnO films on borosilicate glass substrates by rf sputtering and standard photolithographic processing. Unloaded Q values were nearly 1000 and a linear temperature coefficient of about −10 ppm/°C was obtained when operated at a frequency of 100 MHz. Achievable Q values for ZnO/glass SAW resonators at this frequency are discussed.
Effect of adsorbed gases on the conductance of amorphous films of semiconducting silicon-hydrogen alloys
Authors: Tanielian M. , Fritzsche H. , Tsai C. C. , Symbalisty E.
Published: February 2003

The conductance of amorphous Si films produced by glow discharge of SiH4 is found to be very sensitive to various adsorbates such as water, ammonia, and dimethyl ether. Films exposed to air and light must first be heated to 150 °C in vacuum to remove adsorbed moisture and the reversible photoelectronic effect discovered by Staebler and Wronski. When exposed to adsorbates, the conductance of undoped films (about 0.36 μm thick) decreases by several orders of magnitude; the conductance of lightly phosphorus-doped films first increases rapidly and then slowly decreases to a saturation value which lies above the conductance of the annealed films. Heating in vacuum at 150 °C restores the original values. The results indicate that the conductance changes produced by light and by adsorbates are two separate processes, the latter being a surface effect.
A Be p-silicon MIS solar cell
Authors: Maeda Yasuhiro
Published: February 2003

An MIS solar cell, consisting of beryllium on p-type silicon with an interfacial oxide layer, has been found to have good conversion efficiency and good reproducibility. Sunlight conversion efficiency appeared to be more than 9% without the use of an antireflection coating.
Humidity-sensitive threshold switching in silver–boron nitride–silicon–aluminum sandwiches
Authors: Kimura Tadamasa , Yamamoto Katsumi , Yugo Shigemi
Published: February 2003

Conduction of polycrystalline boron nitride films in a form of a Ag-BN-Si-Al sandwich has been investigated. After electroforming, the samples exhibit threshold switching in atmospheres which contain moisture. The switching is well explained by Dearnaley’s filamentary model.
Generalized relativistic Brillouin theory
Authors: Wang M. Y.
Published: February 2003

The Brillouin theory is generalized to an infinitely long vacuum transmission line of arbitrary cross section. It is shown that the equation describing the system can be reduced to a simple Laplace equation. A general expression for the total current is shown to be inversely proportional to the characteristic impedance. An analytical example is presented in the text.
Simultaneous gettering of Au in silicon by phosphorus and dislocations
Authors: Tseng W. F. , Koji T. , Mayer J. W. , Seidel T. E.
Published: February 2003

Gettering in Si may be achieved by either phosphorus diffusion (ion pairing) or by dislocations (strain). We show here by use of backscattering spectrometry and transmission electron microscopy that, in particular, samples of both mechanisms are simultaneously operative. Au is present in a profile which mimics the phosphorus doping, and a spike of Au is superimposed on this profile in the strain field around a narrowly distributed misfit dislocation network. Both profiles are predominately (≳two-thirds) substitutional, implying that local ion pair binding energies exceed the strain binding energy near the dislocations.
Grain growth in polycrystalline silicon
Authors: Jain G. C. , Das B. K. , Bhattacherjee S. P.
Published: February 2003

A grain-growth study of polycrystalline silicon having small dendritic crystallites obtained by cracking SiHCl3 on a hot filament has been carried out in the temperature range 1275–1375 °C. It has been observed that (1) the grain growth in the polycrystalline silicon is due to a two-dimensional motion of grain boundaries in a plane perpendicular to the grain axis, (2) the size-limited grain-growth law is obeyed, and (3) the activation energy of grain growth in polycrystalline silicon is 4.62±0.23 eV, which is nearly the same as the activation energy of the diffusion of Si31 in silicon.
Use of a scanning cw Kr laser to obtain diffusion-free annealing of B-implanted silicon
Authors: Gat A. , Gibbons J. F. , Magee T. J. , Peng J. , Williams P. , Deline V. , Evans C. A.
Published: February 2003

The use of a continuous scanned Kr ion laser as a tool for annealing of boron-implanted silicon is described. Conditions were found that produce high electrical activity and crystallinity of the implanted layer without redistribution of the boron from the as-implanted profile.
As-grown CVD ZnO optical waveguides on sapphire
Authors: Shiosaki T. , Ohnishi S. , Hirokawa Y. , Kawabata A.
Published: February 2003

Optical-waveguide loss was measured in as-grown single-crystalline ZnO films which were chemical-vapor-deposited on intermediately sputter-deposited very thin ZnO films on sapphire substrates. The obtained minimum attenuations at 6328 Å are 18.3, 14.2, 10.7, 8.7, 4.7, 2.4, 1.5, and 0.7 dB/cm for the seventh, sixth, fifth, fourth, third, second, first, and zeroth TE modes, respectively, in a 2.57-μm-thick ZnO film. A strip waveguide was made of the CVD ZnO film selectively grown on an intermediately sputter-deposited ZnO pattern on sapphire.
Use of carbon dioxide in energy storage
Authors: Williams Richard , Crandall Richard S. , Bloom Allen
Published: February 2003

We have investigated an energy-storage cycle in which CO2 is electrochemically reduced to formic acid, HCOOH. The product can be used in several ways. By means of a catalyst, it can be converted to hydrgen for use as a fuel or raw material. We have obtained data on the efficiency of the process and analyzed the energetics.
Self-terminating thermal oxidation of AlAs epilayers grown on GaAs by molecular beam epitaxy
Authors: Tsang W. T.
Published: February 2003

Metal-oxide-semiconductor (MOS) capacitors were prepared by thermal oxidation (wet and dry) of AlAs epilayers grown on GaAs using molecular beam epitaxy (MBE). This oxidation process was found to be self-terminated at the AlAs-GaAs interface. Together with the use of MBE for growing the AlAs-GaAs multilayer structures, the oxide films obtained were extremely uniform over areas ≳6 cm2, possessed sharp oxide-semiconductor interfaces, and precise film thicknesses. Capacitance-voltage measurements on these MOS capacitors displayed inversion behavior and showed little or no hysteresis for oxides prepared by dry oxidation. Measured fixed interface charge density was ∼ (4–6) ×1011 cm−2, while breakdown fields were ∼ (2–4) ×106 V/cm.
Dose dependence in the laser annealing of arsenic-implanted silicon
Authors: Venkatesan T. N. C. , Golovchenko J. A. , Poate J. M. , Cowan P. , Celler G. K.
Published: February 2003

In the laser annealing of silicon by Nd : YAG laser irradiation a dose dependence of the annealing threshold and final impurity depth distribution has been observed. Impurity depth distributions and damage profiles observed by Rutherford backscattering are consistent with the notion of the formation of a thin liquid layer and subsequent regrowth of the crystal upon cooling. We conclude that the annealing behavior is very sensitive to the time of formation of the liquid layer during the laser pulse.
Permanent magnets based on (Ce,Sm)(Co,Fe,Cu)z
Authors: Tawara Yoshio , Chino Tetsuichi , Matsui Yukihiro
Published: February 2003

R T z alloys known as permanent magnet materials were reexamined with particular emphasis on Ce-rich compositions. Performance of Ce-based alloys was much improved by changing the transition-metal compositions from conventional ones. The Ce-based alloys exhibited 14.8 MG Oe of maximum energy product. Use of Sm, not exceeding 30% of the total rare earths, resulted in even higher energy, up to 17 MG Oe.
A unified explanation for secondary ion yields
Authors: Deline V. R. , Evans C. A. , Williams Peter
Published: February 2003

The pure element secondary ion yields under oxygen and cesium ion bombardment are shown to be solely dependent on a) the ionization potential (or electron affinity for negative ionization) of the sputtered atom and b) the reciprocal of the matrix sputtering yield which determines the equilibrium concentration of implanted oxygen or cesium. This unified approach accounts for the yields of C±, Si±, Ge± and Sn± from the pure elements as well as of Ga± and As± from gallium arsenide.
Electroluminescence from the on state of a thin-film chalcogenide glass
Authors: Walsh Peter J. , Ishioka Sachio , Adler David
Published: February 2003

A narrow-band emission has been detected at room temperature during the pulsed on state of a well-characterized threshold switching material, amorphous Te39As36Si17Ge7P1. The luminescence peak is centered around 0.55±0.03 eV, very close to half of the optical band gap of this material, 1.1 eV. This ratio of luminescence peak to optical band gap is similar to that obtained from the photoluminescence of a large class of chalcogenide glasses in their off states, strongly suggesting that the origins of the on-state electroluminescence and off-state photoluminescence are the same. The electroluminescence exhibits a threshold behavior, appearing only for on-state currents in excess of 4 mA. The output follows a Lambertian law for solid angles up to about 0.7 sr, and slowly deviates below the Lambertian law at larger solid angles. The width of the luminescence line is less than 0.1 eV, indicating that its origin cannot be blackbody radiation. This provides another confirmation of the electronic nature of threshold switching.
Length and depth resonances of surface cracks and their use for crack size estimation
Authors: Domarkas V. , Khuri-Yakub B. T. , Kino G. S.
Published: February 2003

Angular scattering from surface cracks has been used for determining the length of a surface crack. This technique assumes the physical availability of space to carry out an angular scattering experiment, and makes no estimation of the depth of the crack. In this work, we report a new technique where the scattering from surface cracks is made versus frequency, at one angle of incidence only. Length and depth resonances of the crack are observed and used to estimate the crack geometry. We made our measurements on EDM notches in steel. The geometry of the crack has been predicted with an accuracy of 10–20%.
Transport and optical properties of electrochromic Au-WO3 cermets
Authors: Sichel E. K. , Gittleman J. I.
Published: February 2003

The electrochromic cermet Au-WO3 is composed of grains of Au, approximately 20–120 Å in diameter, embedded in a matrix of amorphous WO3. The optical properties of the cermet, in its red electrochemically colored state, are different from the optical properties of its two components. WO3 becomes highly electrically conducting when colored, but colored WO3 in the presence of Au grains remains an insulator. A study of the optical and electrical properties of the cermet as a function of gold concentration is presented.
Correlation between process-induced in-plane distortion and wafer bowing in silicon
Authors: Yau L. D.
Published: February 2003

The in-plane distortion of 3-in. wafers which went through high-temperature processing steps was measured directly using the Bell Laboratories electron-beam exposure system (EBES). The magnitude of the in-plane distortion obtained from EBES measurements correlates directly with the change in wafer curvature induced by films grown or deposited on the wafer. Additionally, the nature of the in-plane distortion of wafers processed with an up-to-date silicon technology can be linear to within ±1/8 μm.
Charge transfer by surface acoustic waves on a monolithic MIS structure
Authors: Tsubouchi K. , Higuchi T. , Nagao M. , Mikoshiba N.
Published: February 2003

We have observed the minority-charge signal transferred by surface acoustic waves (SAW) on a monolithic MIS structure. In the Al/ZnO/SiO2/p-Si system, we have made new improvements on the configuration of input and output gates and the channel-stop bias ring along the transfer path, and on the method to prepare the deep-depletion mode by applying the pulse bias at the transfer channel. This type of charge-transfer device by SAW (monolithic SAW-CTD) seems to have some advantages compared with the separated-medium type so far examined.
Temperature rise induced by a laser beam II. The nonlinear case
Authors: Lax M.
Published: February 2003

The steady-state solution of the nonlinear heat-conduction equation when the thermal conductivity is strongly temperature dependent is expressed (for arbitrary geometry and heat source) in terms of the corresponding solution for the linear heat-conduction case. This permits a closed-form expression for the maximum temperature rise when a Gaussian laser beam hits the surface of a crystal, as well as integral representations for the spatial distribution of the temperature rise. This solution is essential in understanding laser annealing.
Generation of cw VUV coherent radiation by four-wave sum frequency mixing in Sr vapor
Authors: Freeman R. R. , Bjorklund G. C. , Economou N. P. , Liao P. F. , Bjorkholm J. E.
Published: February 2003

The production of cw VUV coherent radiation by four-wave sum frequency generation in Sr vapor is reported. Significant enhancement of the nonlinearity at the output frequency is obtained upon application of large (∼50 kG) magnetic fields. Total power of 10−11 W (∼107 photons/sec) at 1700 Å in a bandwidth of approximately 6 GHz for input powers of less than 1 W was obtained.
Surface segregation in LaNi5 induced by oxygen
Authors: von Waldkirch Th. , Zürcher P.
Published: February 2003

LEED and AES studies of LaNi5 single crystals cleaved in UHV and exposed to oxygen and hydrogen show that surface segregation of La is induced at room temperature by oxygen, but not by hydrogen. This segregation is driven by the chemical exchange reaction (La-Ni)+O→ (La-O)+Ni. A surface-layer model is derived supporting the important implications of the segregation for the excellent kinetics in hydrogenation and the resistance to contaminants.
Effect of electrode shielding on beamlet-beamlet interaction in multiaperture sources
Authors: Whealton J. H.
Published: February 2003

Extension of previous work on beamlet-beamlet interaction is made in two phases. The effect of beam space-charge truncation due to electrode shielding is considered. For a typical geometry multiaperture source, the ion divergence is thus reduced by a factor of 30, assuming all the beamlets interact with each other, and by a factor of 5, assuming only nearest-neighbor beamlets interact. To account accurately for electrode shielding, a direct solution to the Poisson-Vlasov equation was made for a similar physical situation. For a typical circumstance it shows an additional decrease of a factor of 5 for both the global and nearest-neighbor calculation. These results indicate that beamlet-beamlet interaction is small for typical ion sources.
Photoacoustic determination of photovoltaic energy conversion efficiency
Authors: Cahen David
Published: February 2003

Photoacoustic (i.e., photocalorimetric) measurements on photovoltaic devices can directly yield their energy conversion efficiency. This is illustrated for a Si solar cell, for which case excellent agreement is found with normal electrical measurements. In addition, the photoacoustic spectra under load and at open-circuit conditions are reported and compared with the cell’s spectral response. Together, such measurements can provide information on the wavelength dependence of the cell performance as well.
Selective annealing of ion-implanted amorphous layers by Nd3+-YAG laser irradiation
Authors: Miyao M. , Tamura M. , Tokuyama T.
Published: February 2003

Annealing behavior of phosphorus-implanted silicon layers under Q-switched Nd3+-YAG laser irradiation was examined for samples with various dose (1014−1016 cm−2). Annealing efficiency in the implanted layer was found to be strongly influenced by the degree of damage to the substrate, namely, the annealing effect was localized to the amorphous regions. This selective annealing of the amorphous region was explained by the difference in the absorption coefficient of laser energy between crystalline and amorphous silicon.
The etching of silicon with XeF2 vapor
Authors: Winters H. F. , Coburn J. W.
Published: February 2003

It is shown that silicon is isotropically etched by exposure to XeF2(gas) at T=300 K. Si etch rates as large as 7000 Å/min were observed for P (XeF2) <1.4×10−2 Torr and the etch rate varies linearly with P (XeF2). There was no observable etching of SiO2, Si3N4, or SiC, demonstrating an extremely large selectivity between silicon and its compounds. Therefore, thin masks constructed from silicon compounds can be used for pattern delineation. The implication of these experimental results for understanding mechanisms associated with plasma etching (including RIE) will be discussed.
The thermal-expansion parameters of some GaxIn1−xAsyP1−x alloys
Authors: Bisaro R. , Merenda P. , Pearsall T. P.
Published: February 2003

The coefficient of thermal expansion has been determined in the temperature range 25–400 °C for InP, the ternary alloy Ga0.47In0.53As, and the quaternary alloy Ga0.26In0.74As0.40P0.60 grown on (100) InP by liquid-phase epitaxy. This parameter is (4.56±0.10) ×10−6/°C for InP, (5.42±0.10) ×10−6/°C for Ga0.26In0.74As0.60P0.40, and (5.66±0.10) ×10−6/°C for Ga0.47In0.53As.
Field-ion microscopy of liquid-metal gallium
Authors: Sakurai Toshio , Culbertson R. J. , Robertson G. H.
Published: February 2003

Ionization of liquid gallium coated on a tungsten field-ion tip was investigated using a magnetic-sector atom probe. For the first time, both the energy distribution of ionized Ga and its critical energy deficit with respect to a tip potential were measured as a function of field and tip temperature. Without heating the gallium, a stable Ga+ ion current of up to 10 μA was obtained from a small surface area of a tip with an energy distribution of less than 12 eV FWHM.
Conical targets for implosion studies with a CO2 laser
Authors: Mason R. J. , Fries R. J. , Farnum E. H.
Published: February 2003

The design, fabrication, and testing of conical laser fusion targets is described. These are DT-filled conical holes in lead, 190 μm deep and covered with a 132-μm-diam plastic cap. The results of two-dimensional simulations of the cones are displayed. Experimentally, up to 2.8×105 neutrons have been obtained from the exploding pusher implosion of such a target under single-beam CO2 illumination of the cap at 0.13 TW.
Gold, silver, chromium, and copper cermet selective surfaces for evacuated solar collectors
Authors: McKenzie D. R.
Published: February 2003

Cermet solar selective surfaces of absorptance over 0.90 and emittance less than 0.05 have been prepared by vacuum coevaporation of alumina and spinel with gold, silver, chromium, and copper. Grading of commposition was employed to enhance the absorptance. The effect of heat treatment in vacuum up to 500 °C was studied and the chromium-alumina cermet shown to be the best candidate for vacuum-insulated collectors.
Quantitative energy extraction measurements in a photoionization-stabilized self-sustained XeF laser
Authors: Lee C. M. , Hasson V. , Rowley P. D. , Exberger R.
Published: February 2003

Detailed time-correlated gain, flourescence, and laser energy measurements were used to obtain quantitative data on energy extraction efficiencies for a photoionization-stabilized self-sustained XeF laser. A current pulse of 25 ns full width at half-maximum produced an 80-cm3 XeF plasma in NF3 : Xe : He gas mixtures with a maximum output energy of 80 mJ. The results show that the maximum small-signal gain and the maximum specific output energy is proportional to the NF3 content of the gas mixture. This suggests that there is an optimum fractional utilization of the NF3 molecules in the discharge. Under high-gain conditions, 30–40% of the energy stored in XeF* can be extracted in a gain-switched pulse. The output energy represents less than 1% of the input energy.
Preparation of n-type semiconducting Ge20Bi10Se70 glass
Authors: Tohge Noboru , Yamamoto Yoshitaka , Minami Tsutomu , Tanaka Masami
Published: February 2003

Chalcogenide bulk glasses exhibiting n-type conduction were first prepared by quenching the melts of mixtures of Ge, Se, and Bi2Se3 or Bi. The conditions for obtaining homogeneous glasses were examined, and measurements of resistivity and thermoelectric power were carried out on Ge20Bi10Se70 glass, one of the typical n-type semiconducting glasses in the system Ge-Bi-Se. The results indicated that the electrical properties of homogeneous glasses were slightly affected by the difference in starting materials, and the resistivity and thermoelectric power were about 3×107 Ω cm and −1.4 mV/K at room temperature, respectively.
Alkali-metal resonance-line lasers based on photodissociation
Authors: Ehrlich D. J. , Osgood R. M.
Published: February 2003

We report on a series of new lasers involving transitions in Na, K, Rb, and Cs. Pulsed output powers of 1–10 kW have been obtained on the alkali-metal resonance lines. Details of the photodissociative excitation process have been studied in order to optimize these lasers.
Stimulated spin-flip Raman scattering in a Pb0.88Sn0.12Te single crystal
Authors: Yasuda K. , Shirafuji J.
Published: February 2003

Stimulated spin-flip Raman emission assisted by resonance enhancement has been observed in an n-type Pb0.88Sn0.12Te single crystal pumped by a TE CO2 laser. The wavelength of the Stokes emission can be tuned in a range from 10.8 to 11.8 μm for the pumping wavelength at 10.54 μm in the magnetic field range between 8 and 40 kG. The effective g value, when a magnetic field is applied along the 〈100〉 axis, is from 50 to 64, depending on the magnetic field. The intensity of the Stokes emission is strongly dependent upon the magnetic field.
A near-infrared fiber Raman oscillator tunable from 1.07 to 1.32 μm
Authors: Lin Chinlon , French W. G.
Published: February 2003

We report a near-infrared fiber Raman oscillator in the 1.1–1.3-μm spectral region. The Raman medium is an 800-m-long 6.3-μm-core-diam single-mode fiber with a loss less than 2 dB/km near 1.2 μm and less than 4 dB/km over the 1–1.32-μm spectral range. The oscillator is synchronously pumped by a cw mode-locked Nd : YAG laser. With four separate resonator mirrors, four orders of Stokes oscillations, peaked near 1.12, 1.18, 1.24, and 1.31 μm, are obtained. With simultaneous tuning of all the four Stokes wavelengths we have achieved continuously tunable oscillation over 250 nm (1.07–1.32 μm), the first such broadly tunable laser in this spectral range.
Laser-generated MHz elastic waves from metallic-liquid interfaces
Authors: von Gutfeld R. J. , Budd H. F.
Published: February 2003

The thermoelastic generation of MHz waves from a three-layer structure consisting of a transparent substrate with an evaporated metallic film in contact with a liquid is described. Results with laser excitation indicate the magnitude of the strain wave to be strongly dependent on the expansion coefficient of the liquid and thickness of the metal film. The data are compared to a three-medium one-dimensional theory. Some practical applications such as nondestructive evaluation are discussed using this structure.
655 mV open-circuit voltage, 17.6% efficient silicon MIS solar cells
Authors: Godfrey R. B. , Green M. A.
Published: February 2003

Major new results are reported for silicon MIS solar cells. Open-circuit voltages up to 655 mV (AM0, 25 °C) have been obtained for 0.1-Ω cm silicon wafers, substantially higher than previously reported for any other silicon solar cell. On an active-area basis, the efficiency of these high-output-voltage cells is close to the best silicon cell yet produced with 17.6% active-area efficiency (AM1, 28 °C) for a 3-cm2 cell.
Energy-resolved DLTS measurement of interface states in MIS structures
Authors: Johnson N. M.
Published: February 2003

A new method is described for determining the energy of emitting centers in an interface-state continuum independently of the emission rate in transient-capacitance measurements on MIS structures. Deep-level transient spectroscopy (DLTS) is performed in the double-correlation mode to analyze the energy profile of a continuous interface-trap distribution. With this method, DLTS can be used to evaluate interface-state distributions with energy-dependent capture cross sections, and the extraneous effects of bulk defect levels in the semiconductor are minimized. Experimental results are presented for electron traps at the Si-SiO2 interface.
Magneto-optic current sensing with birefringent fibers
Authors: Rashleigh S. C. , Ulrich R.
Published: February 2003

To measure currents on high-voltage lines, the Faraday rotation is used in a single-mode optical fiber encircling the conductor. Disturbing linear birefringence is suppressed by twisting the fiber. With ∼10 m of fiber, coiled with a 3-cm radius, we obtain 0.25 mrad/A polarization rotation, permitting measurement of currents of 0.2–2000 A.
Phenomenological theory of the acoustophotorefractive effect
Authors: Leavitt Richard P.
Published: February 2003

A theory of the acoustophotorefractive effect is proposed in which photocarriers excited by intense visible illumination of a LiNbO3 sample migrate under the influence of the electric field associated with a surface acoustic wave propagating in the material. The theory accounts for saturation of photocarriers due to the finite number of traps; comparison of computations using this theory with experiments shows that the observed dependence of the effect on acoustic wave power, light intensity, and light pulse width are in agreement with the theoretical predictions.
Prediction of anelastic loss in piezoelectric solids: Effect of geometry
Authors: Lakes Roderic S.
Published: February 2003

The anelastic loss of a piezoelectric material is calculated from its complex dielectric and piezoelectric coefficients. This loss is found to be dependent on specimen geometry. It is shown that neglect of the out-of-phase piezoelectric modulus, as in earlier analyses, leads to an overestimate of the anelastic loss.
Pulsed-laser annealing of ion-implanted polycrystalline silicon films
Authors: Wu C. P. , Magee C. W.
Published: February 2003

Polysilicon films, about 0.6 μm thick, deposited on SiO2 grown on silicon substrates, were implanted with different doses of 11B, 31P, or 75As ions and laser annealed with a Q-switched Nd-glass or ruby laser. It was found that complete activation of the implanted dopant ions could be achieved with a pulse power density as low as 16 MW/cm2, that a two to three times reduction of resistivity could be achieved in implanted polysilicon films compared with samples thermally annealed, and that there were little or no redistributions of the implanted profiles.
Buried-grid fabrication by silicon liquid-phase epitaxy
Authors: Baliga B. Jayant
Published: February 2003

This paper describes the application of silicon liquid phase epitaxy for the fabrication of buried-grid regions. It is demonstrated here that closely spaced buried-grid regions can be fabricated by this technique if the melt is supersaturated prior to epitaxial growth.
Absorption of laser radiation by Al, Fe, and Au planar metallic targets
Authors: Anthes J. P. , Palmer M. A. , Gusinow M. A. , Matzen M. K.
Published: February 2003

Experiments to determine the absorptance of an 8-nsec (FWHM) 1.064-μm laser pulse incident on metallic targets were performed using a well-characterized integrating sphere photometer. The absorptance was inferred by individually measuring the incident, back reflectd, and scattered laser radiation over the range ≃1013–1014 W/cm2 for three different elemental planr targets (Al, Fe, and Au). The absorptance varied approximately linearly from 0.9 at 1013 W/cm2 at 1014 W/cm2 and was independent of target material. The experimental accuracy was ±4%.
Determination of dielectric relaxation time as a function of pressure and temperature by the thermally stimulated current method
Authors: Ai Bui , Popescu Stoka Corina , Giam Hoang The , Destruel Pierre
Published: February 2003

The thermally stimulated current (TSC) has been used over a wide range of pressure to determine the principal characteristics of the polymers such as the activation volume ΔV, the activation energy ΔE, and the preexponential term τ0 of the Arrhenius-type relaxation time: τ=τ0 exp[(PΔV+ΔE)/kT]. Experimentally, the 6-Polyamide sample is subjected to a high hydrostatic pressure before application of the classical TSC method. The variation law of the relaxation time, a function of temperature and pressure, τ (P,T), of this polymer is given by the determination of these characteristics with the initial slope analysis of the TSC experimental curves.
cw laser recrystallization of 〈100〉 Si on amorphous substrates
Authors: Gibbons J. F. , Lee K. F. , Magee T. J. , Peng J. , Ormond R.
Published: February 2003

A polycrystalline silicon film 0.55 μm thick was deposited in a low-pressure CVD reactor on a Si3N4 substrate. Islands of various sizes (2×20 μm up to 20×160 μm) were prepared by standard photolithographic techniques. Laser annealing was then performed under conditions which are known to cause an increase in grain size from ∼500 Å to long narrow crystals of 2×25 μm in a continuous polysilicon film. These same conditions were found to produce single-crystal 〈100〉 material in the (2×20 μm) islands. However, 25×25-μm and 20×160-μm islands remain polycrystalline after the laser scan.
Photoacoustic Raman spectroscopy (PARS) using cw laser sources
Authors: Barrett Joseph J. , Berry Michael J.
Published: February 2003

We have devised a new nonlinear spectroscopic technique, photoacoustic Raman spectroscopy (PARS), which uses acoustic methods to detect energy deposited in a molecular gas by the process of stimulated Raman scattering. The technique was demonstrated by stimulated Raman excitation of the 2916.7-cm−1 ν1 symmetric stretch vibrational mode of CH4 using two cw laser sources (an argon ion laser at 514.5 nm and a tunable dye laser near 605.4 nm). Excellent agreement between calculated and experimentally observed PARS signals was obtained for CH4.
Amorphous silicon as a passivant for crystalline silicon
Authors: Pankove J. I. , Tarng M. L.
Published: February 2003

Hydrogenated amorphous silicon deposited on a p-n junction in crystalline silicon causes a two-order-of-magnitude reduction in leakage current compared to the performance of a state-of-the-art thermal oxide passivant.
Ion-beam-induced silicide formation
Authors: Tsaur B. Y. , Liau Z. L. , Mayer J. W.
Published: February 2003

Rutherford-backscattering spectrometry and x-ray-diffraction analysis have been used to investigate intermixing between thin metal films (Pt, Ni, and Hf) and silicon substrates as a result of inert-gas ion bombardment. Silicide phases (Pt2Si, Ni2Si, and HfSi) were observed near the interface as long as the ion range exceeds the film thickness. For a fixed dose, the silicide thickness increases with the atomic mass of both ion and metal and is greater for Pt2Si than HfSi. The growth of Pt2Si showed a square-root dependence on ion dose for Ar, Kr, and Xe ions. The phenomenon of ion-induced silicide formation is similar to formation resulting from thermal anneal until the whole metal film is consumed in the reaction, at which point a progressive intermixing to redistribute the metal into deeper regions of the sample occurred along with the disappearance of the structure diffraction patterns.
Generation of horizontally polarized shear waves in ferromagnetic materials using magnetostrictively coupled meander-coil electromagnetic transducers
Authors: Thompson R. Bruce
Published: February 2003

A new electromagnetic transducer configuration is described for generating horizontally polarized shear (SH) waves in ferromagnetic materials. The transducer consists of a meander coil and static bias magnetic field parallel to the coil elements. This configuration generates no ultrasonic waves in a nonmagnetic metal since the induced eddy currents are parallel to the bias field and the driving Lorentz forces vanish. However, the configuration provides coupling to SH waves in ferromagnetic materials through magnetostrictive effects. Experimental measurements of the variation of transduction efficiency with bias field in nickel and 4130 steel plate are presented and compared to the efficiency obtained with the same meander coils when the bias is rotated 90° in the plane of the plate so that antisymmetric Lamb waves are generated. Peak efficiencies occur at considerably different bias fields for the two configurations. This result, as well as other features in the data, are interpreted in terms of a simple model.
A modulated submillimeter-laser polarimeter for the measurement of the Faraday rotation by a plasma
Authors: Ma C. H. , Hutchinson D. P. , Vander Sluis K. L.
Published: February 2003

To determine current-density profiles in toroidal plasmas, a submillimeter-laser polarimeter was fabricated and its perfomance assessed. Measurements of simulated plasma Faraday rotations demonstrated a sensitivity of 26 mV/mrad for an optically pumped 4-mW 393-μm far-infrared (FIR) laser and a polarization modulation angle of 149 mrad. Time resolution of the order of milliseconds was obtained.
Long-range enhancement of boron diffusivity induced by a high-surface-concentration phosphorus diffusion
Authors: Lecrosnier D. , Gauneau M. , Paugam J. , Pelous G. , Richou F.
Published: February 2003

Enhanced boron diffusivity of buried implanted layers has been investigated when a shallow diffusion is performed with phosphorus. For low surface phosphorus concentration (<1019/cm3) no diffusion of boron was observed, but for higher values (≳1020/cm3) a strong diffusion occurs. This enhancement is a function of the distance between the boron layer and surface phosphorus diffusion. Results are explained by vacancy-type defects generated during the phosphorus diffusion. A 30-μm diffusion length is found for these defects.
RED display structures having dynamic hysteresis characteristics
Authors: Van Uitert L. G. , Camlibel I. , DeLaRue R. M. , Kyle T. R. , Pawelek R. , Singh S. , Stocker H. J. , Zydzik G. J.
Published: February 2003

Display structures based on reversible electrodeposition (RED) in organic solvent based electrolytes containing tetra-alkyl ammonium iodide, ammonium iodide, and silver iodide have been studied. Cells were made up with these electrolytes together with a mixed opacifier containing a semiconducting oxide (such as impure TiO2) and an insulator (such as a very fine zeolite powder). The cells develop bistable characteristics which permit operation with good contrast (between deep burgundy and white) at drive voltages of less than 2 V while operating at 0.5 Hz. Contrast ratio, optical density, efficiency, and memory time were measured. Probable mechanisms for the development of bistable characteristics and the nature of the deposits are discussed.
Electronic density of states in discharge-produced amorphous silicon
Authors: Hirose M. , Suzuki T. , Döhler G. H.
Published: February 2003

The localized state density distribution in the mobility gap of glow-discharge amorphous silicon has been determined from capacitance-voltage characteristics for metal/oxide/amorphous silicon (MOS) structures. This new method provides a smooth distribution of localized states throughout the mobility gap. The density of states increases from a minimum of the order of 1016 cm−3 eV−1 near midgap to more than 1018–1019 cm−3 eV−1 within 0.2 eV of the band edges.
Direct observation of two-dimensional lattice mismatch parallel to the interfacial boundary between the LPE Ga0.65Al0.35As layer and the GaAs substrate
Authors: Chang Shih-Lin
Published: February 2003

Previously unreported two-dimensional lattice mismatch in planes parallel to the interfacial boundary between the (001) Ga0.65Al0.35As epitaxial layer and the GaAs substrate has been observed by utilizing a four-beam, (000), (400), (220), and (22̄0), simultaneous Borrmann diffraction of x rays. The shifts of the reflection bands of the layer from the reflection lines of the substrate indicate that shear stresses exist in 〈100〉 and 〈010〉 directions and that the corresponding strains vary continuously along the thickness direction of the epilayer.
Chemical-vapor-deposited molybdenum films of high infrared reflectance
Authors: Carver G. E. , Seraphin B. O.
Published: February 2003

Molybdenum thin films deposited by pyrolytic decomposition of molybdenum carbonyl attain, after anneal in a reducing atmosphere at 1000 °C, infrared reflectance values within 0.7% of the reflectance of supersmooth bulk molybdenum. This result combines the refractory nature of molybdenum with the high infrared reflectance generally associated with conventional mirror materials. The entire production sequence proceeds at atmospheric pressure and requires less than 1 h. The reflectance increase during anneal is related to compositional and structural properties of the films. The importance of this development to photothermal solar-energy conversion and high-energy laser technology is stressed.
Single layer conductance of cadmium behenate in the Langmuir multilayer assembly system
Authors: Sugi Michio , Iizima Sigeru
Published: February 2003

A frequency dispersion of conductance has been observed in a heterogeneous multilayer system of Cd-behenate and Cd-stearate in accordance with the hopping theory of the multilayer assemblies. The values of the single-layer dc conductance evaluated for Cd-behenate are consistent with those for palmitate, stearate, and arachidate, suggesting the availability of the heterogeneous multilayer system for the evaluation of the bulk conductivity of a single monolayer.
Work function of sintered lanthanum hexaboride
Authors: Pelletier J. , Pomot C.
Published: February 2003

A work function of 2.36 eV and a Richardson constant of 120 A/cm2 K2 have been measured for a hot-pressed porous lanthanum hexaboride rod cathode. It is shown that the LaB6 work function is highly susceptible to poisoning by molybdenum deposited at high temperatures during experiments. A stable work function of about 2.7 eV is then measured. After removal of the molybdenum by atomic iodine flux, the work function of clean LaB6 is restored.
Nature of the 0.111-eV acceptor level in indium-doped silicon
Authors: Baron R. , Baukus J. P. , Allen S. D. , McGill T. C. , Young M. H. , Kimura H. , Winston H. V. , Marsh O. J.
Published: February 2003

Strong evidence is presented that the X-level defect, which produces a 0.111-eV acceptor level in Si : In, is a substitional In–substitutional C (Ins-Cs) pair. The concentration of this defect follows a mass-action law with the In and C concentrations, the association constant being (1.4±0.3) ×10−19 cm−3 at 650 °C. Reversible changes in the X-level concentration between anneal temperatures of 650 and 850 °C are observed, and a pair binding energy of 0.7±0.1 eV is estimated. The electronic properties and temperature dependence of the concentration of this center are found to be those expected for a nearest-neighbor Ins-Cs pair.
Passivation of grain boundaries in polycrystalline silicon
Authors: Seager C. H. , Ginley D. S.
Published: February 2003

Preferential diffusion of various gases down the grain boundaries in polycrystalline silicon is shown to promote significant changes in the density of defect states in these regions. A plasma of monatomic hydrogen provides a significant reduction in both the state density and the accompanying grain-boundary potential barrier while plasmas of oxygen, nitrogen, and sulfur hexafluoride are shown to increase this density of states. Boundaries passivated with hydrogen have as much as a factor of 1000 larger transconductance after treatment. Hydrogenated barriers are stable over long periods at 375 °C and essentially indefinitely at 23 °C. The results have important implications for the development of low-cost thin-film silicon photovoltaic devices.
Nonlinear sputtering effects in thin metal films
Authors: Thompson D. A. , Johar S. S.
Published: February 2003

The sputtering yields of Ag, Au, and Pt have been measured for monatomic and polyatomic ions of P, As, Sb, and Bi over the energy range 15–135 keV. Very lare enhancements of the sputtering yields over those predicted by linear cascade theory have been observed. These enhancements appear to be consistent with a strong contribution resulting from the near-surface region of the impact area and that the complete collision cascade, even for high energy densities, plays a lesser and possibly minor role. It is also shown that the enhancements can in no way be explained based upon a thermal model in which the localized high-temperature zone is responsible for an evaporation component.
Low-noise 115-GHz mixing in superconducting oxide-barrier tunnel junctions
Authors: Dolan G. J. , Phillips T. G. , Woody D. P.
Published: February 2003

Small-area (≲1 μm2) oxide-barrier tunnel junctions have been made of thermally cyclable superconducting Pb alloys for use as high-frequency mixers. A single-sideband mixer noise temperature of <100 K has been achieved at 115 GHz. This result was achieved in the quasiparticle (classical) mixing mode.
New ion laser transitions in copper, silver, and gold
Authors: Jain Kanti
Published: February 2003

Using hollow-cathode excitation techniques, laser oscillation is obtained at eight new transitions in copper-helium, silver-helium, and gold-helium discharges. All the transitions are in the near-infrared region and a majority of them are excited on a cw basis. Four of the transitions are obtained in Cu II, two in Ag II, and two in Au II. Lower threshold currents are also reported for five previously observed transitions.
Investigation of nematic ordering using electric-field-induced second-harmonic generation
Authors: Saha S. K. , Wong George K.
Published: February 2003

The macroscopic third-order nonlinearity Γ of a nematic liquid crystal has been measured for the first time with the technique of dc electric-field-induced optical second-harmonic generation. The effect of nematic ordering on Γ is observed. Results are in good agreement with theoretical calculations.
Piezoelectric oscillations in PLZT pyroelectric detectors in response to short CO2 laser pulses
Authors: Simhony M. , Bass M.
Published: February 2003

Piezoelectric (PZE) oscillations superimposed on the pyroelectric (PRE) voltage response to short (<50 nsec) single CO2 laser pulses in PLZT detectors are shown to have an incubation time, i.e., to start after the beginning of the PRE response. During the incubation time (40–60 nsec, depending on sample geometry) the PRE response is not disturbed, thus PRE detectors for use with short ir pulses can be designed with minimum PZE interference. The initial PZE amplitudes were 0.05–0.4 of the observed peak PRE voltages. The periods of the PZE oscillations with the measured lengths of the samples gave 2.2 km/sec for the velocity of sound in PLZT.
Vibrational dephasing measurements with cw mode-locked dye lasers
Authors: Heritage Jonathan P.
Published: February 2003

Recent advances in the development of synchronously mode-locked dye-laser systems have permitted the first low-power measurement of the time-resolved dephasing dynamics of a Raman active molecular vibration. Excitation and delayed probing of the coherent ensemble of vibrators is accomplished with the help of synchronized picosecond pulse trains from two independently tunable mode-locked dye lasers. A new probe technique, based on a gain measurement, is employed that provides a signal that scales linearly with the coherent vibrational amplitude. We demonstrate this technique with the first measurement of the dephasing dynamics of the normal mode (656.5 cm−1) of CS2 in the liquid state. An exponential decay with time constant 20±1 psec is obtained for the isotropic component of the coherent scattering.
Transmission cathodoluminescence: A new SEM technique to study defects in bulk semiconductor samples
Authors: Chin A. K. , Temkin H. , Roedel R. J.
Published: February 2003

We report a new method of defect electron microscopy which is an extension of the well-known method of cathodoluminescence. In this new technique, which we call transmission cathodoluminescence, the luminescence generated at the top surface of a thick semiconductor sample by the electron beam of a scanning electron microscope (SEM) is used to probe the sample volume beneath the luminescing region. The intensity of the transmitted luminescence collected by a small solid-state detector mounted beneath the sample is displayed on the cathode ray tube of the SEM. We demonstrate the usefulness of this technique by imaging dislocations in GaAs substrates and GaAlAs epitaxial layers.
Excited-state kinetics for Nd(thd)3 and Tb(thd)3 chelate vapors and prospects as fusion laser media
Authors: Jacobs Ralph R. , Krupke William F.
Published: February 2003

Fluorescence decays for the Nd3+ : 4F3/2→4I11/2 transition at 1.06 μm and the Tb3+ : 5D4→7F5 transition at 545 nm were studied, using the vapor-phase carrier chelate 2,2,6,6-tetramethyl-3, 5-heptanedione and pulsed-laser excitation, as functions of (1) ground- and excited-state molecular densities and (2) local temperature. In each case, inferred excited-state densities 1016–1017 cm−3 were sustained for times greater than several hundred nanoseconds.
Optical modulation by optical tuning of a cavity
Authors: Gibbs H. M. , Venkatesan T. N. C. , McCall S. L. , Passner A. , Gossard A. C. , Wiegmann W.
Published: February 2003

A signal beam transmitted by a Fabry-Perot cavity is modulated by a control beam which changes the refractive index of the intracavity medium. High finesse at the signal wavelength and strong absorption at the control wavelengths result in efficient optical gating and modulation. Such modulation has been observed using GaAs (and using color filters) with switch-on times of 1 ns (10 μs) and switch-off times of 2–20 ns (1 ms), and a physical length of only 5 μm (60 μm).
Deep-level luminescence in AlxGa1−xAs double-heterostructure lasers
Authors: van der Ziel J. P. , Hartman R. L.
Published: February 2003

It is shown that the deep level (∼1.0 eV) luminescence observed in double-heterostructure lasers originates from the E3 radiation damage trap (Ga vacancy) or a closely related vacancy-donor complex in the n-type GaAs substrate region rather than in the active region as had been reported previously.
Long-term Hall-type conversion by vacancy diffusion in Hg1−xCdxTe at room temperature
Authors: Nimtz G. , Schlicht B. , Dornhaus R.
Published: February 2003

Drastic long-term changes of transport properties and the recombination behavior of a Hg1−xCdxTe crystal are reported. Being pure n-type material immediately after fabrication the crystal showed a p-type conduction after a five-year storage under room-temperature conditions. The lifetime—formerly dominated by Auger recombination—dropped by about two orders of magnitude. A model of Hg vacancy diffusion is suggested to explain the observed data.
The effect of doping on microdefect formation in as-grown dislocation-free Czochralski silicon crystals
Authors: de Kock A. J. R. , Stacy W. T. , van de Wijgert W. M.
Published: February 2003

The influence of p- and n-type doping on microdefect formation in macroscopically dislocation-free as-grown Czochralski silicon crystals has been studied using copper decoration, x-ray transmission topography, preferential etching, and high-voltage transmission electron microscopy. B-doped crystals are found to contain undecorated perfect dislocation loops of an interstitial nature. In Sb-doped crystals two other types of microdefects are present, one of which consists of a precipitate particle exhibiting a vacancy type of strain field. All defects are distributed in a striated pattern.