APL Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

26 Jan 1998

Volume 72, Issue 4, pp. 395-509

Page 1 of 2 Pages Next Page | Jump to Page
back to top
RSS Feeds

All-optical inverter operating over a temperature range of 15–1400 K in erbium-doped lutetium aluminum garnet

Yoshinobu Maeda

Appl. Phys. Lett. 72, 395 (1998); http://dx.doi.org/10.1063/1.120768 (3 pages) | Cited 11 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
An all-optical inverter, which operates over a range of 15–1400 K, was demonstrated in an erbium-doped lutetium aluminum garnet crystal with 787.3, 787.9 and 790 nm laser diodes. In the case of 787.3 nm, the reversed-phase wave forms were obtained in a temperature range of 15–1100 K. In the case of 787.9 and 790 nm, they were observed up to 1400 K. It has been confirmed that the negative nonlinear absorption effect can be explained by considering an enhanced absorption model for a five-level system of the Er3+ ion. The effect has a characteristic, which is almost independent of the ambient temperature because it is formed by optical transitions of the inner shell of the erbium atom. © 1998 American Institute of Physics.
Show PACS
42.65.-k Nonlinear optics
42.79.Ta Optical computers, logic elements, interconnects, switches; neural networks

Optical mixing to 211 GHz using 50 nm gate pseudomorphic high electron mobility transistors

M. E. Ali, D. Bhattacharya, H. R. Fetterman, and M. Matloubian

Appl. Phys. Lett. 72, 398 (1998); http://dx.doi.org/10.1063/1.120769 (3 pages) | Cited 1 time

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report optical mixing with difference frequencies to 211 GHz in 50 nm gate pseudomorphic InP-based high electron mobility transistors (HEMTs). To our knowledge, this is the highest frequency optical mixing signal obtained in three terminal devices. To detect the signals at these frequencies, a novel three-wave-mixing configuration was employed. To demonstrate the wide tunability of this setup, a sweep of frequencies from 160 to 190 GHz was performed. The optically generated millimeter wave signals were downconverted to 97 GHz and radiated. For the radiation experiments, tunable baseband signals were also added by injection into the gate terminal of our HEMTs, thereby providing a method to transmit information. © 1998 American Institute of Physics.
Show PACS
85.30.Tv Field effect devices
42.65.Jx Beam trapping, self-focusing and defocusing; self-phase modulation
84.37.+q Measurements in electric variables (including voltage, current, resistance, capacitance, inductance, impedance, and admittance, etc.)
42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation

Raman effect based modulator for high power fiber lasers

I. Torres, A. N. Starodumov, Yu. O. Barmenkov, L. A. Zenteno, and P. Gavrilovic

Appl. Phys. Lett. 72, 401 (1998); http://dx.doi.org/10.1063/1.120770 (3 pages) | Cited 3 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We demonstrate experimentally an all-fiber nonlinear optical modulator which can find application for high power (greater than 20 W) single-mode fiber lasers. Stimulated Raman scattering is used to transfer the amplitude modulation from a low-power signal beam at the Stokes frequency onto a high-power beam. Efficient modulation of 1064 nm pump radiation by 100 ps Stokes pulses is demonstrated in a highly Ge-doped fiber. © 1998 American Institute of Physics.
Show PACS
42.60.Fc Modulation, tuning, and mode locking
42.79.Hp Optical processors, correlators, and modulators
42.55.Wd Fiber lasers
42.65.Dr Stimulated Raman scattering; CARS
42.65.Es Stimulated Brillouin and Rayleigh scattering
42.55.Ye Raman lasers

Loss measurements on semiconductor lasers by Fourier analysis of the emission spectra

Daniel Hofstetter and Robert L. Thornton

Appl. Phys. Lett. 72, 404 (1998); http://dx.doi.org/10.1063/1.120771 (3 pages) | Cited 10 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present a study on a novel method for the determination of the cavity losses in semiconductor lasers. The method we use involves Fourier analysis of the Fabry–Pérot mode spectrum when operating the device below lasing threshold. The observation of the decay rate of higher order harmonics in the Fourier analysis of the spectra allows us to determine the amount of cavity propagation loss/gain. A comparison between experimental and calculated data for an AlGaInP laser at 670 nm showed good agreement up to an injection current of 0.93×Ith. This method therefore provides a generalization of the Fabry–Pérot contrast measurement method for extracting cavity losses from spectral information. © 1998 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.60.Da Resonators, cavities, amplifiers, arrays, and rings
78.40.Fy Semiconductors

Amplified spontaneous emission of an Nd3+-doped poly(methyl methacrylate) optical fiber at ambient temperature

Q. J. Zhang, P. Wang, X. F. Sun, Y. Zhai, P. Dai, B. Yang, M. Hai, and J. P. Xie

Appl. Phys. Lett. 72, 407 (1998); http://dx.doi.org/10.1063/1.120772 (3 pages) | Cited 29 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Polymer optical fibers have received much attention in recent years as they can replace silica glass fibers in local area nets in the future. A neodymium ion (Nd3+)-doped poly(methyl methacrylate) (PMMA) fiber has been made from Nd3+ containing PMMA as a core and silica resin as claddings. Fluorescence of the fiber results from the transition of 4G5/2 to 4I9/2 in a three energy level system. Amplified spontaneous emission (ASE) at 575 nm has also been observed and the critical power at a pump wavelength of 514.5 nm for the onset of ASE has been found to be 85 mW. © 1998 American Institute of Physics.
Show PACS
42.50.Nn Quantum optical phenomena in absorbing, amplifying, dispersive and conducting media; cooperative phenomena in quantum optical systems
42.70.Jk Polymers and organics
81.05.Lg Polymers and plastics; rubber; synthetic and natural fibers; organometallic and organic materials
42.81.Bm Fabrication, cladding, and splicing
78.45.+h Stimulated emission
78.55.Kz Solid organic materials

Organic solid-state lasers with imprinted gratings on plastic substrates

M. Berggren, A. Dodabalapur, R. E. Slusher, A. Timko, and O. Nalamasu

Appl. Phys. Lett. 72, 410 (1998); http://dx.doi.org/10.1063/1.120773 (2 pages) | Cited 77 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Optically pumped laser emission has been observed from thin films of 8-hydroxyquinolinato aluminum (Alq) doped with a DCM dye deposited on a diffraction grating formed by imprinting a film of BCB with a mold. The BCB film, which is 4 μm thick, is deposited on a silicon or a flexible plastic substrate. Laser emission occurs at a wavelength near 655 nm which corresponds to the third order of the grating, which has a periodicity of ∼ 0.6 μm. © 1998 American Institute of Physics.
Show PACS
42.55.Rz Doped-insulator lasers and other solid state lasers
42.60.By Design of specific laser systems
42.79.Dj Gratings
42.86.+b Optical workshop techniques

Generation of programmable multi-wavelength picosecond pulses using an optical-loop-mirror multiplexer

K. S. Lee and C. Shu

Appl. Phys. Lett. 72, 412 (1998); http://dx.doi.org/10.1063/1.120774 (3 pages) | Cited 1 time

Full Text: Read Online (HTML) | Download PDF

Show Abstract
An all fiberoptic configuration to generate multi-wavelength picosecond optical pulses by self-seeding of a gain-switched 1.53 μm semiconductor laser has been proposed and experimentally demonstrated. The configuration consists of a 600 m highly dispersive fiber and an optical loop mirror multiplexer. Four-wavelength optical pulses with a spectral separation of 2.6 nm, a side-mode-suppression ratio of 16 to 20 dB, and a pulse width of 75 ps have been generated. The repetition rate of these pulses has been multiplied to 3.4 GHz, and totally 13.6 Gb/s (4×3.4 Gb/s) pulse signals have been produced. With the optical bit patterns generated from the multiplexer, output pulses with one, two, or four wavelengths at different combinations can be obtained. © 1998 American Institute of Physics.
Show PACS
42.65.Re Ultrafast processes; optical pulse generation and pulse compression
42.79.Sz Optical communication systems, multiplexers, and demultiplexers
42.79.Bh Lenses, prisms and mirrors
42.81.Qb Fiber waveguides, couplers, and arrays
42.55.Px Semiconductor lasers; laser diodes
42.81.Dp Propagation, scattering, and losses; solitons

Ultraviolet and violet GaN light emitting diodes on silicon

Supratik Guha and Nestor A. Bojarczuk

Appl. Phys. Lett. 72, 415 (1998); http://dx.doi.org/10.1063/1.120775 (3 pages) | Cited 55 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report the fabrication and characterization of GaN-based double heterostructure light emitting diodes grown by molecular beam epitaxy on Si(111) substrates. Light emitting diode operation is achieved by using the conducting Si(111) substrate as a backside n contact and a standard transparent Ni/Au p contact. We observe electroluminescence peaked in the ultraviolet ∼ 360 nm, with a full width at half maximum of ∼ 17 nm and in the violet at ∼420 nm. Electron microscopy studies indicate a high density of threading and planar defects. Consequences of these are discussed. © 1998 American Institute of Physics.
Show PACS
85.60.Jb Light-emitting devices
78.60.Fi Electroluminescence
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
68.55.-a Thin film structure and morphology
81.05.Ea III-V semiconductors
81.05.Cy Elemental semiconductors
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions

Image storage based on biphotonic holography in azo/polymer system

Pengfei Wu, Xiaochun Wu, Li Wang, Jiren Xu, Bingsuo Zou, Xiong Gong, and Wei Huang

Appl. Phys. Lett. 72, 418 (1998); http://dx.doi.org/10.1063/1.120776 (3 pages) | Cited 9 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Image storage has been investigated with the biphotonic holographic method in an azo/polymer film. Experimental results show that this biphotonic holographic storage has high spatial resolution and exhibits an image enhancement effect after blocking the noncoherent light. The mechanism of biphotonic holographic storage is attributed to the redistribution of cis form azo molecules induced by both coherent light and noncoherent light. © 1998 American Institute of Physics.
Show PACS
42.70.Ln Holographic recording materials; optical storage media
42.79.Vb Optical storage systems, optical disks
42.40.Ht Hologram recording and readout methods
42.30.Va Image forming and processing
42.70.Jk Polymers and organics
back to top
RSS Feeds

Analytic expression for triple-point electron emission from an ideal edge

Levi Schächter

Appl. Phys. Lett. 72, 421 (1998); http://dx.doi.org/10.1063/1.120802 (3 pages) | Cited 25 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The electric field in the vicinity of a metallic edge attached to a dielectric half-space is calculated analytically. The resulting electric field is used to evaluate the current emitted from the edge using the Fowler-Nordheim formula. It is shown analytically that the emitted current is proportional to the dielectric coefficient of the material. © 1998 American Institute of Physics.
Show PACS
79.70.+q Field emission, ionization, evaporation, and desorption
back to top
RSS Feeds

Observation of {105} facetted Ge pyramids inclined towards vicinal Si(001) surfaces

Jian-hong Zhu, K. Brunner, and G. Abstreiter

Appl. Phys. Lett. 72, 424 (1998); http://dx.doi.org/10.1063/1.120777 (3 pages) | Cited 23 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Self-assembled Ge and SiGe islands, which are compact pyramids with four equivalent {105} facets, have been grown by molecular beam epitaxy on vicinal Si(001) surfaces with biatomic surface steps along the [110] direction. Revealed by atomic force microscopy, they appear as regularly facetted pyramids which are inclined by the miscut angles of 2.8° or 4° toward the sample surfaces and consequently have a distorted rhomb base. Characteristic patterns are observed by reflection high-energy electron diffraction from these facetted islands. They agree well with simulated patterns scattered by {105} facets. Avoiding elongated Ge hut clusters by using vicinal surfaces is promising for an improved homogeneity in island shape and size. © 1998 American Institute of Physics.
Show PACS
68.55.-a Thin film structure and morphology
68.35.Ct Interface structure and roughness
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
81.05.Cy Elemental semiconductors
81.05.Hd Other semiconductors

Strain-induced change in the elastically soft direction of epitaxially grown face-centered-cubic metals

V. Ozoliņš, C. Wolverton, and Alex Zunger

Appl. Phys. Lett. 72, 427 (1998); http://dx.doi.org/10.1063/1.120778 (3 pages) | Cited 8 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The theory of epitaxial strain energy is extended beyond the harmonic approximation to account for large film/substrate lattice mismatch. We find that for fcc noble metals (i) directions 〈001〉 and 〈111〉 soften under tensile biaxial strain (unlike zincblende semiconductors) while (ii) 〈110〉 and 〈201〉 soften under compressive biaxial strain. Consequently, (iii) upon sufficient compression 〈201〉 becomes the softest direction (lowest elastic energy), but (iv) 〈110〉 is the hardest direction for large tensile strain. (v) The dramatic softening of 〈001〉 in fcc noble metals upon biaxial tensile strain is caused by small fcc/bcc energy differences for these materials. These results can be used in selecting the substrate orientation for effective epitaxial growth of pure elements and ApBq superlattices, as well as to explain the shapes of coherent precipitates in phase separating alloys. © 1998 American Institute of Physics.
Show PACS
68.55.-a Thin film structure and morphology
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties
62.20.F- Deformation and plasticity
64.75.-g Phase equilibria

Localized switching in photorefractive ferroelectrics induced by spatially inhomogeneous electric fields

J. Fousek, M. Marvan, and R. S. Cudney

Appl. Phys. Lett. 72, 430 (1998); http://dx.doi.org/10.1063/1.120779 (3 pages) | Cited 4 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We examine theoretically the stability of 180° domain patterns that may form inside photorefractive ferroelectric crystals when an optically induced spatially modulated electric field is present. By analyzing the total free energy of a ferroelectric crystal subjected to an applied field and with free charges contained within, we find under what conditions (magnitude of the applied field, amplitude of the optically induced electric field, and domain-wall energy density) the spontaneous polarization of the crystal tends to switch throughout the whole crystal and under which only partial switching occurs. © 1998 American Institute of Physics.
Show PACS
77.80.Fm Switching phenomena
72.40.+w Photoconduction and photovoltaic effects
77.80.Dj Domain structure; hysteresis
77.22.Ej Polarization and depolarization
65.20.-w Thermal properties of liquids
65.40.gd Entropy

Effects of oxidation process on interface roughness of gate oxides on silicon: X-ray reflectivity study

S. Banerjee, Y. J. Park, D. R. Lee, Y. H. Jeong, K.-B. Lee, S. B. Yoon, B. H. Jo, H. M. Choi, and W.-J. Cho

Appl. Phys. Lett. 72, 433 (1998); http://dx.doi.org/10.1063/1.120780 (3 pages) | Cited 14 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on the effects of the wet and dry oxidation processes on the interfacial roughness and time dependent dielectric breakdown (TDDB) characteristics of the poly-Si/SiO2/Si(100) trilayer. The interface roughness of the oxide layers buried under a thick poly-Si electrode has been investigated using an x-ray reflectivity technique. Analysis of x-ray reflectivity data for the trilayer samples and for a bare oxide film shows that interface roughness of poly-Si electrode/SiO2 interfaces depends on oxidation process while oxide layers have smooth SiO2/Si-subtstrate interfaces. TDDB of the SiO2 layer has also been observed to depend on the oxidation process, indicating that the interface roughness is a crucial factor affecting the TDDB characteristics. The wet oxidized SiO2 film is more stable to dielectric breakdown and has smoother interfaces than the dry oxidized sample. © 1998 American Institute of Physics.
Show PACS
81.05.Cy Elemental semiconductors
81.65.Mq Oxidation
77.22.Jp Dielectric breakdown and space-charge effects
68.35.Ct Interface structure and roughness
back to top
RSS Feeds

Alloying effects on the critical layer thickness in InxGa1−xAs/InP heterostructures analyzed by Raman scattering

P. S. Pizani, T. M. Boschi, F. Lanciotti, J. Groenen, R. Carles, P. Maigné, and M. Gendry

Appl. Phys. Lett. 72, 436 (1998); http://dx.doi.org/10.1063/1.120800 (3 pages) | Cited 8 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Raman scattering has been used to estimate the critical layer thickness and to analyze the alloying effect on strain relaxation in InxGa1−xAs layers grown by molecular beam epitaxy on InP [001]-oriented substrate, for x ranging from 0.0 to 1.0. Measurements of longitudinal optical GaAs-like phonon frequency and Raman linewidth showed that the indium/gallium ratio contents greatly influences the strain relaxation. A comparison between Raman and x-ray diffraction measurements of relaxation ratios as a function of layer thickness is presented. The results can be explained in terms of the combined effect of strain and chemical and structural disorder. © 1998 American Institute of Physics.
Show PACS
68.60.Bs Mechanical and acoustical properties
68.55.-a Thin film structure and morphology
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
78.66.Fd III-V semiconductors
78.30.Fs III-V and II-VI semiconductors

Trapping and recombination dynamics of low-temperature-grown InGaAs/InAlAs multiple quantum wells

Yue Chen, S. S. Prabhu, Stephen E. Ralph, and Dave T. McInturff

Appl. Phys. Lett. 72, 439 (1998); http://dx.doi.org/10.1063/1.120766 (3 pages) | Cited 21 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have observed a long-lived residual photoconductivity in low-temperature-grown (LT) InGaAs. These results have significant consequences for devices comprised of LT-InGaAs, other defect moderated materials, and standard-temperature-grown InGaAs. Our investigation utilizes time-resolved terahertz conductivity to quantify the trapping and recombination rates of LT Be-doped In0.53Ga0.47As/In0.52Al0.48As multiple quantum wells and bulk InGaAs. It is found that Be doping reduces the residual photoconductivity and increases the initial electron trapping rate. These results are in contrast to those observed via transient absorption studies, which suggest that these systems have returned to equilibrium after the initial transient. Furthermore, a 600 °C anneal increases both the trapping and recombination rate in all Be-doped samples. © 1998 American Institute of Physics.
Show PACS
73.61.Ey III-V semiconductors
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
73.50.Gr Charge carriers: generation, recombination, lifetime, trapping, mean free paths
72.40.+w Photoconduction and photovoltaic effects
73.50.Pz Photoconduction and photovoltaic effects
72.30.+q High-frequency effects; plasma effects
73.50.Mx High-frequency effects; plasma effects

The behavior of As precipitates in low-temperature-grown GaAs

J. C. Bourgoin, K. Khirouni, and M. Stellmacher

Appl. Phys. Lett. 72, 442 (1998); http://dx.doi.org/10.1063/1.120781 (3 pages) | Cited 10 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We analyze the kinetics associated with the concentration and the growth of As precipitates during annealing in low-temperature-grown GaAs layers. We correlate them with that associated with the annealing of the As antisite related defect. This allows us to deduce that all these kinetics are governed by the mobility of the As interstitial whose migration energy is 0.44 eV. © 1998 American Institute of Physics.  
Show PACS
81.30.Mh Solid-phase precipitation
64.75.-g Phase equilibria
81.40.Gh Other heat and thermomechanical treatments
61.72.Cc Kinetics of defect formation and annealing
61.72.J- Point defects and defect clusters
66.30.H- Self-diffusion and ionic conduction in nonmetals

A 3 kV Schottky barrier diode in 4H-SiC

Q. Wahab, T. Kimoto, A. Ellison, C. Hallin, M. Tuominen, R. Yakimova, A. Henry, J. P. Bergman, and E. Janzén

Appl. Phys. Lett. 72, 445 (1998); http://dx.doi.org/10.1063/1.120782 (3 pages) | Cited 29 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
High-voltage Schottky barrier diodes with low reverse leakage current were processed on hot-wall chemical vapor deposition grown 4H-SiC films. A metal overlap onto the oxide layer was employed to reduce electric field crowding at the contact periphery. By utilizing a 42–47 μm thick, high-quality epitaxial layers with doping in the range of 7×1014–2×1015 cm−3, a record blocking voltage of above 3 kV was achieved. The large diodes with 1.0 mm diameter showed breakdown at 2.1 kV. The reverse leakage current density at 1.0 kV was measured to be 7.0×10−7 A cm−2. Specific on-resistance of the diode with breakdown voltage at 3 kV was 34 mΩ cm2. © 1998 American Institute of Physics.
Show PACS
85.30.Kk Junction diodes
85.30.Hi Surface barrier, boundary, and point contact devices
77.22.Jp Dielectric breakdown and space-charge effects

Electron-irradiation-induced deep level in n-type GaN

Z.-Q. Fang, J. W. Hemsky, D. C. Look, and M. P. Mack

Appl. Phys. Lett. 72, 448 (1998); http://dx.doi.org/10.1063/1.120783 (2 pages) | Cited 54 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Deep-level transient spectroscopy measurements of n-type GaN epitaxial layers irradiated with 1-MeV electrons reveal an irradiation-induced electron trap at EC−0.18 eV. The production rate is approximately 0.2 cm−1, lower than the rate of 1 cm−1 found for the N vacancy by Hall-effect studies. The defect trap cannot be firmly identified at this time. © 1998 American Institute of Physics.
Show PACS
71.55.Eq III-V semiconductors
73.61.Ey III-V semiconductors
61.80.Fe Electron and positron radiation effects
61.72.J- Point defects and defect clusters
72.20.My Galvanomagnetic and other magnetotransport effects
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
72.80.Ey III-V and II-VI semiconductors

On the behavior of deuterium in ultrathin SiO2 films upon thermal annealing

I. J. R. Baumvol, E. P. Gusev, F. C. Stedile, F. L. Freire, M. L. Green, and D. Brasen

Appl. Phys. Lett. 72, 450 (1998); http://dx.doi.org/10.1063/1.120801 (3 pages) | Cited 18 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Following the observation of the large isotopic effect in D2 passivated gate dielectrics [J. Lyding, K. Hess, and I. C. Kizilyalli, Appl. Phys. Lett. 68, 2526 (1996)], we studied the behavior of deuterium in ultrathin SiO2 films by nuclear reaction analysis techniques. Accurate concentrations of deuterium in the films, deuterium depth distributions, and deuterium removal from the film upon thermal annealing in vacuum have been examined. For D2 passivated films, we found rather high concentrations of deuterium near the SiO2/Si interface, well above both the solubility of deuterium in silica and the maximum concentration of electrically active defects at the interface. Our results suggest a complex multistep mechanism of thermally activated deuterium removal from the film, which probably consists of D detrapping, diffusion, and desorption steps. © 1998 American Institute of Physics.
Show PACS
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
61.72.Cc Kinetics of defect formation and annealing
81.40.Gh Other heat and thermomechanical treatments
81.65.Rv Passivation
82.80.Jp Activation analysis and other radiochemical methods
61.72.S- Impurities in crystals
68.35.Ct Interface structure and roughness
64.75.-g Phase equilibria
66.30.J- Diffusion of impurities
68.03.Fg Evaporation and condensation of liquids
68.43.Mn Adsorption kinetics

Energy resolved noise measurements in quantum well infrared photodetectors

J. Yao, C. J. Chen, K. K. Choi, W. H. Chang, and D. C. Tsui

Appl. Phys. Lett. 72, 453 (1998); http://dx.doi.org/10.1063/1.120784 (3 pages) | Cited 2 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In quantum well infrared photodetectors, the detector dark current usually is composed of a wide range of energies originated from thermionic emission as well as thermally assisted tunneling. Yet, it is a common practice to assign a single noise gain to all electrons irrespective of their energies. This assigned value can only represent the mean since both the hot-electron lifetime and the transit time, whose ratio determines the gain, are energy dependent. In this work, we have resolved the energy dependence of the noise gain using an electron energy filter. We find that although the noise gain increases initially with energy as expected, it reaches a maximum at 0.27 eV above the GaAs conduction band edge, and then decreases and forms a minimum at 0.31 eV. We attribute this decrease to the Γ-L intervalley scattering, which increases the transit time of the electrons. © 1998 American Institute of Physics.
Show PACS
85.60.Gz Photodetectors (including infrared and CCD detectors)
07.57.Kp Bolometers; infrared, submillimeter wave, microwave, and radiowave receivers and detectors
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)
79.40.+z Thermionic emission
72.20.Ht High-field and nonlinear effects
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
72.70.+m Noise processes and phenomena
73.61.Ey III-V semiconductors

Hydrogen abstraction kinetics and crystallization in low temperature plasma deposition of silicon

Easwar Srinivasan and Gregory N. Parsons

Appl. Phys. Lett. 72, 456 (1998); http://dx.doi.org/10.1063/1.120785 (3 pages) | Cited 20 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Exposing a plasma deposited hydrogenated silicon layer to atomic hydrogen results in hydrogen removal from the silicon/hydrogen surface and a net reduction in the total hydrogen content in the layer. For deposition at low temperature, the crystallization fraction corresponds directly with the extent of hydrogen removal. Silicon films deposited using alternating deposition and hydrogen (or deuterium) plasma exposure are characterized by transmission infrared spectroscopy and Raman spectroscopy. Using mass spectroscopy, hydrogen abstraction and etching are observed and identified as important pathways for hydrogen removal at substrate temperatures between 25 °C and 300 °C. Moreover, the hydrogen abstraction kinetics show that the reaction is first order with an activation barrier of −0.4±1 kcal/mol, consistent with a spontaneous Eley–Rideal abstraction process. Energy barrier values are supported by ab initio calculations. © 1998 American Institute of Physics.
Show PACS
81.05.Cy Elemental semiconductors
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
52.77.Bn Etching and cleaning
52.77.Dq Plasma-based ion implantation and deposition
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces
78.30.Am Elemental semiconductors and insulators
78.66.Db Elemental semiconductors and insulators

Doping of AlxGa1−xN

C. Stampfl and Chris G. Van de Walle

Appl. Phys. Lett. 72, 459 (1998); http://dx.doi.org/10.1063/1.120803 (3 pages) | Cited 59 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
N-type AlxGa1−xN exhibits a dramatic decrease in the free-carrier concentration for x ≥ 0.40. Based on first-principles calculations, we propose that two effects are responsible for this behavior: (i) in the case of doping with oxygen (the most common unintentional donor), a DX transition occurs, which converts the shallow donor into a deep level; and (ii) compensation by the cation vacancy (VGa or VAl), a triple acceptor, increases with alloy composition x. For p-type doping, the calculations indicate that the doping efficiency decreases due to compensation by the nitrogen vacancy. In addition, an increase in the acceptor ionization energy is found with increasing x. © 1998 American Institute of Physics.
Show PACS
61.72.uj III-V and II-VI semiconductors
61.72.J- Point defects and defect clusters
71.55.Eq III-V semiconductors
72.80.Ey III-V and II-VI semiconductors
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping

Excess silicon at the Si3N4/SiO2 interface

V. A. Gritsenko, I. P. Petrenko, S. N. Svitasheva, and Hei Wong

Appl. Phys. Lett. 72, 462 (1998); http://dx.doi.org/10.1063/1.120786 (3 pages) | Cited 12 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Using electron energy loss spectroscopy, X-ray photoelectronic spectroscopy, and ellipsometry measurements, a large number of Si-Si bonds at the Si3N4/thermal SiO2 interface is confirmed. After etching away the surface SiO2 of reoxidized Si3N4, we found at the Si3N4/SiO2 interface that the plasmon energy on the surface is 20 eV which is smaller than the bulk plasmon of either Si3N4 (24.0 eV) or SiO2 (23.0 eV). From ellipsometric measurement, a large value of the refractive index (n = 2.1) in the Si3N4/ wet SiO2 interface layer was obtained. The effective width of the Si-rich interfacial layer is estimated to be in the range of 6–8 Å. We propose that the excess silicon at the Si3N4/SiO2 interface is created by replacing nitrogen atoms with the oxygen atoms during the oxidation of Si3N4. Based on these observations and on numerical simulation, a hypothesis is proposed to explain the abnormally large electron capturing at the Si3N4/SiO2 interface observed previously and the accumulation of positive charge at the top interface of the nitrided oxide under ionizing irradiation. © 1998 American Institute of Physics.
Show PACS
79.60.Jv Interfaces; heterostructures; nanostructures
79.20.Kz Other electron-impact emission phenomena
61.85.+p Channeling phenomena (blocking, energy loss, etc.)
68.35.Ct Interface structure and roughness
81.65.Cf Surface cleaning, etching, patterning
81.65.Mq Oxidation
81.05.Je Ceramics and refractories (including borides, carbides, hydrides, nitrides, oxides, and silicides)
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
73.20.Mf Collective excitations (including excitons, polarons, plasmons and other charge-density excitations)

Stacked GaAs multi-quantum wires grown on vicinal GaAs(110) surfaces by molecular beam epitaxy

Takehiko Kato, Toshikazu Takeuchi, Yoshiji Inoue, Shigehiko Hasegawa, Koichi Inoue, and Hisao Nakashima

Appl. Phys. Lett. 72, 465 (1998); http://dx.doi.org/10.1063/1.120787 (3 pages) | Cited 10 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Stacked GaAs quantum wires (QWRs) are grown on the surfaces with giant steps which are naturally formed on vicinal GaAs(110) substrates by molecular beam epitaxy. Transmission electron microscopy observation clearly shows stacked structures of coherently aligned quantum wires which are induced by GaAs layer thickness modulation at the step edges. Photoluminescence peak shifts with the thickness of the AlGaAs barrier layers are explained as due to the coupling between the QWRs. © 1998 American Institute of Physics.
Show PACS
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
81.05.Ea III-V semiconductors
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties
78.66.Fd III-V semiconductors
78.55.Cr III-V semiconductors
Page 1 of 2 Pages Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close