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

9 Sep 1996

Volume 69, Issue 11, pp. 1503-1648

Page 2 of 2 Pages Previous Page | Jump to Page

Ultrastable emission from a metal–oxide–semiconductor field‐effect transistor‐structured Si emitter tip

Junji Itoh, Takayuki Hirano, and Seigo Kanemaru

Appl. Phys. Lett. 69, 1577 (1996); http://dx.doi.org/10.1063/1.117035 (2 pages) | Cited 21 times

Full Text: | Download PDF

Show Abstract
A silicon field emitter tip with a dual‐gate metal–oxide–semiconductor field‐effect transistor (MOSFET) structure was fabricated and demonstrated. The present tip structure is just the same as an n‐channel MOSFET whose drain was replaced by a cone‐shaped Si tip. Two coplanar gates of 0.3‐μm‐thick Nb are made on a 0.6‐μm‐thick thermally oxidized SiO2 insulator between the source and the tip and make inversion layers in a p‐type Si substrate under each gate. One of the gates has a 1.8‐μm‐diam aperture surrounding the tip for extraction of electrons from the tip. The other is 3 μm wide and 300 μm long and is separated by 2 μm from this gate. Ultrastable emission of about 0.3 μA was demonstrated with a single tip for one day. © 1996 American Institute of Physics.
Show PACS
79.70.+q Field emission, ionization, evaporation, and desorption
85.45.Db Field emitters and arrays, cold electron emitters

An optical study of interdiffusion in ZnSe/ZnCdSe

M. K. Chai, S. F. Wee, K. P. Homewood, W. P. Gillin, T. Cloitre, and R. L. Aulombard

Appl. Phys. Lett. 69, 1579 (1996); http://dx.doi.org/10.1063/1.117036 (3 pages) | Cited 9 times

Full Text: | Download PDF

Show Abstract
This letter presents a study of intermixing in ZnSe/ZnCdSe quantum well structures, using repetitive thermal annealing with photoluminescence measurements. An improvement in the optical quality of the samples was found for anneals at temperatures (∼500 °C) for which macroscopic intermixing is not observed. The interdiffusion process of this system was found to be Fickian with no dependence on alloy composition or strain. An activation energy of 2.3±0.2 eV was obtained for the interdiffusion process over a 250 K temperature range and four decades of interdiffusion coefficient. © 1996 American Institute of Physics.
Show PACS
66.30.Ny Chemical interdiffusion; diffusion barriers
78.55.Et II-VI semiconductors

Densification of amorphous silicon prepared by hydrogen‐ion‐beam‐assisted evaporation

H. Rinnert, M. Vergnat, G. Marchal, and A. Burneau

Appl. Phys. Lett. 69, 1582 (1996); http://dx.doi.org/10.1063/1.117037 (3 pages) | Cited 9 times

Full Text: | Download PDF

Show Abstract
Hydrogenated amorphous silicon films were deposited by ion‐beam‐assisted evaporation onto substrates maintained at 120 °C. The influence of the substrate bias was studied. By combined infrared spectrometry and thermal desorption spectrometry experiments, it is inferred that the bombardment of the growing a‐Si:H film by energetic hydrogen ions produces a densification of the material without modification of the Si:H bonding. © 1996 American Institute of Physics.
Show PACS
81.15.Jj Ion and electron beam-assisted deposition; ion plating
61.43.Dq Amorphous semiconductors, metals, and alloys
78.35.+c Brillouin and Rayleigh scattering; other light scattering

Direct determination of carrier capture times in low‐dimensional semiconductor lasers: The role of quantum capture in high speed modulation

Jian Wang, Uwe A. Griesinger, and Heinz Schweizer

Appl. Phys. Lett. 69, 1585 (1996); http://dx.doi.org/10.1063/1.117038 (3 pages) | Cited 9 times

Full Text: | Download PDF

Show Abstract
The effective carrier capture time, which limits the maximum modulation bandwidth of low‐dimensional semiconductor lasers, can be determined by a simple technique as shown in this letter. For demonstration, the technique is applied to InGaAs/InGaAsP multi‐quantum well, InGaAs/GaAs single quantum well and InGaAs/InGaAsP wire lasers, respectively, at low temperature (2 K). Moreover, by comparing quantum‐well lasers with wire lasers, which have different packing densities of the active regions but approximately the same carrier diffusion length before capture, we found that the effective carrier capture times for these two laser types are quite different. This shows the significant role of the scale‐up factor in the contribution of quantum capture time to the total effective carrier capture time, as discussed by S. C. Kan et al. [Appl. Phys. Lett. 62, 2307 (1993)]. © 1996 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
78.47.-p Spectroscopy of solid state dynamics

Universal curves for optical power degradation of II–VI light‐emitting diodes

S. L. Chuang, M. Ukita, S. Kijima, S. Taniguchi, and A. Ishibashi

Appl. Phys. Lett. 69, 1588 (1996); http://dx.doi.org/10.1063/1.117039 (3 pages) | Cited 21 times

Full Text: | Download PDF

Show Abstract
We propose a transient recombination‐enhanced defect‐generation model to analyze the degradation of optical output powers of blue‐green II–VI light‐emitting diodes (LEDs). We find an analytical solution and discover a set of universal curves for the time dependence of optical output power, which agree very well with the experimental data for strained CdZnSe quantum‐well structures. Our model shows that the optical power can be non‐exponential in character and its long‐time behavior has a 1/t dependence. This 1/t dependence is also related to the growth of the defect density, which should behave as a t1/2 dependence. The generation of new defects due to electron‐hole recombination at the defect sites is found to be the dominant degradation mechanism for II–VI LEDs. © 1996 American Institute of Physics.
Show PACS
85.60.Jb Light-emitting devices
78.66.Hf II-VI semiconductors
61.72.Bb Theories and models of crystal defects

Effect of BF2 implantation on ultrathin gate oxide reliability

Chuan Lin, Anthony I. Chou, Kiran Kumar, Prasenjit Choudhury, and Jack C. Lee

Appl. Phys. Lett. 69, 1591 (1996); http://dx.doi.org/10.1063/1.117040 (2 pages) | Cited 2 times

Full Text: | Download PDF

Show Abstract
BF2 implantation is widely used to form P wells, adjust channel threshold voltage, and reduce short channel effects. In this letter, we study effect of BF2 implantation on ultrathin gate oxide reliability. It has been found that BF2 implantation into Si substrate causes degradation of gate oxide reliability in the ultrathin oxide thickness regime. N2O oxide can be used to reduce degradation caused by the implantation and improve gate oxide reliability. © 1996 American Institute of Physics.
Show PACS
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
85.40.Ry Impurity doping, diffusion and ion implantation technology
73.61.Ng Insulators

Mapping electrically active dopant profiles by field‐emission scanning electron microscopy

R. Turan, D. D. Perovic, and D. C. Houghton

Appl. Phys. Lett. 69, 1593 (1996); http://dx.doi.org/10.1063/1.117041 (3 pages) | Cited 21 times

Full Text: | Download PDF

Show Abstract
Secondary electron (SE) image contrast from p‐type silicon has been studied using field‐emission scanning electron microscopy (FE‐SEM). Cross‐sectional FE‐SEM images of boron‐doped silicon heterostructures have been compared with atomic concentration and free carrier profiles measured by secondary‐ion mass spectroscopy and electrochemical capacitance‐voltage profiling, respectively. FE‐SEM image contrast due to dopants has been shown to be electronic in origin. Since electrically active dopant species contribute solely to SE image contrast, FE‐SEM can be effectively used to map electrically active dopant profiles in two dimensions with a sensitivity as low as 1016 cm−3. © 1996 American Institute of Physics.
Show PACS
61.72.S- Impurities in crystals
68.37.Vj Field emission and field-ion microscopy

Longitudinal optical phonon relaxation in a GaAs/AlGaAs triple barrier tunnel diode at strong perpendicular magnetic fields

C. Wirner, Y. Awano, T. Mori, N. Yokoyama, T. Nakagawa, H. Bando, and S. Muto

Appl. Phys. Lett. 69, 1596 (1996); http://dx.doi.org/10.1063/1.117042 (3 pages) | Cited 5 times

Full Text: | Download PDF

Show Abstract
Longitudinal optical (LO) phonon relaxation is investigated in a GaAs/AlGaAs triple barrier tunnel diode at strong perpendicular magnetic fields. We observe LO‐phonon assisted tunneling to the ground state as well as to Landau level states. Maxima in the LO‐phonon assisted tunnel peak are found each time the LO‐phonon energy matches multiple of the Landau level spacing. Corresponding maxima as well as parity effects are found in the integral tunnel conductance. The results indicate enhancement of LO‐phonon assisted inter Landau level transitions with increasing magnetic field. © 1996 American Institute of Physics.
Show PACS
73.40.Gk Tunneling
63.22.-m Phonons or vibrational states in low-dimensional structures and nanoscale materials
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)

Characterization of interface charge at Ga0.52In0.48P/GaAs junctions using current–voltage and capacitance–voltage measurements

T. H. Lim, T. J. Miller, F. Williamson, and M. I. Nathan

Appl. Phys. Lett. 69, 1599 (1996); http://dx.doi.org/10.1063/1.117043 (3 pages) | Cited 12 times

Full Text: | Download PDF

Show Abstract
Al/i:GaInP/n:GaAs Schottky structures of varying undoped layer thicknesses (100–1000 Å) were grown in situ by gas source molecular beam epitaxy (GSMBE). Effective Schottky barrier heights (ϕbIV)of 0.87±0.02 eV were determined from the current–voltage (I–V) method with ideality factor of <1.05 which is characteristic of thermionic emission but a decrease in barrier height (ϕbCV) with increasing GaInP thickness as measured by the capacitance–voltage (C–V) method was observed. We found that the plot of ϕbIV minus ϕbCV versus GaInP thickness is a straight line. This can be explained by modeling a positive delta sheet charge at the GaInP/GaAs interface which will result in a constant electric field (slope of the above line) with sheet charge estimated to be 5×1011 cm−2. This sheet charge is proposed to be the result of ionized donor states at such interface. © 1996 American Institute of Physics.
Show PACS
73.30.+y Surface double layers, Schottky barriers, and work functions
73.20.At Surface states, band structure, electron density of states

Cathodoluminescence study of the influence of misfit dislocations on hole accumulation in an n‐AlGaAs/p‐GaAs/n‐InGaAs heterojunction phototransistor

H. T. Lin, D. H. Rich, O. Sjölund, M. Ghisoni, and A. Larsson

Appl. Phys. Lett. 69, 1602 (1996); http://dx.doi.org/10.1063/1.117044 (3 pages) | Cited 3 times

Full Text: | Download PDF

Show Abstract
We have studied the influence of misfit dislocations on hole accumulation in the base layer of an n‐AlGaAs/p‐GaAs/n‐InGaAs heterojunction phototransistor (HPT). Spatially and temporally resolved cathodoluminescence (CL) measurements reveal that variations in the hole accumulation is caused primarily by strain‐induced defects which impede the transport of holes in the collector. The lifetime of holes in the InGaAs/GaAs collector is found to be negligibly affected by the underlying misfit dislocations in the InGaAs/GaAs collector. The reduction in the local electron‐beam‐induced current signal by the dislocations is less than ∼20%, indicating that these defects have a minor impact on the overall device performance. © 1996 American Institute of Physics.
Show PACS
78.60.Hk Cathodoluminescence, ionoluminescence
85.60.Dw Photodiodes; phototransistors; photoresistors
61.72.Lk Linear defects: dislocations, disclinations
68.37.Hk Scanning electron microscopy (SEM) (including EBIC)
68.37.Lp Transmission electron microscopy (TEM)

Time‐dependent study of low energy electron beam irradiation of Mg‐doped GaN grown by metalorganic chemical vapor deposition

X. Li and J. J. Coleman

Appl. Phys. Lett. 69, 1605 (1996); http://dx.doi.org/10.1063/1.117045 (3 pages) | Cited 21 times

Full Text: | Download PDF

Show Abstract
We have investigated the low energy electron beam irradiation (LEEBI) annealing kinetics of Mg‐doped GaN films grown by metalorganic chemical vapor deposition. Our results show that LEEBI annealing at room temperature, monitored by cathodoluminescence spectroscopy as a function of irradiation time, occurs rapidly initially and then proceeds gradually until saturation. We have also demonstrated that LEEBI annealing is effective even at liquid helium temperature, indicating its athermal mechanism. Our observations support the dynamic model involving electronically stimulated dissociation of Mg–H bonds and the escaping and retrapping of atomic hydrogens. © 1996 American Institute of Physics.
Show PACS
61.72.Cc Kinetics of defect formation and annealing
61.80.Fe Electron and positron radiation effects
78.60.Hk Cathodoluminescence, ionoluminescence

Fabrication of flexible monocrystalline ZnSe‐based foils and membranes

J. Haetty, M. H. Na, H. C. Chang, H. Luo, and A. Petrou

Appl. Phys. Lett. 69, 1608 (1996); http://dx.doi.org/10.1063/1.117046 (3 pages) | Cited 1 time

Full Text: | Download PDF

Show Abstract
We report the successful fabrication of flexible single crystal semiconductor structures. A highly selective etching solution allowed us to obtain large area foils and membranes of good structural integrity, using films of indium and silicone as flexible substrates. Photoluminescence and transmission measurements verified that the optical properties of these structures were preserved. © 1996 American Institute of Physics.
Show PACS
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
78.55.Et II-VI semiconductors
78.66.Hf II-VI semiconductors

Fabrication of electron injecting Mg:Ag alloy electrodes for organic light‐emitting diodes with radio frequency magnetron sputter deposition

Hiroyuki Suzuki

Appl. Phys. Lett. 69, 1611 (1996); http://dx.doi.org/10.1063/1.117047 (3 pages) | Cited 16 times

Full Text: | Download PDF

Show Abstract
Electron injecting electrodes made of magnesium and silver alloys (Mg:Ag) with a wide range of Ag concentration from 0 to 26.6 at. % were successfully fabricated for organic light‐emitting diodes (LEDs) by using the radio frequency sputter deposition technique. The LED characteristics such as intensity, turn‐on voltage, and durability of electroluminescence were strongly dependent on the Mg:Ag composition. Both the work function and the structural order of these Mg:Ag electrodes played a crucial role in determining the LED characteristics. © 1996 American Institute of Physics.
Show PACS
85.60.Jb Light-emitting devices
81.15.Cd Deposition by sputtering
78.66.Qn Polymers; organic compounds

Photoluminescence study of InAsSb/InAsSbP heterostructures grown by low‐pressure metalorganic chemical vapor deposition

S. Kim, M. Erdtmann, D. Wu, E. Kass, H. Yi, J. Diaz, and M. Razeghi

Appl. Phys. Lett. 69, 1614 (1996); http://dx.doi.org/10.1063/1.117048 (3 pages) | Cited 16 times

Full Text: | Download PDF

Show Abstract
Photoluminescence has been measured for double‐ and separate‐confinement InAsSb/InAsSbP heterostructures grown by low‐pressure metalorganic vapor deposition. A measurement of the integrated luminescence intensity at the temperature range of 77–300 K shows that over a wide range of excitation level (1–5×102 W/cm2) the radiative transitions are the dominant mechanism below T∼170 K. Auger recombination coefficient C=C0 exp(−Ea/kT) with C0≊5×10−27 cm6/s and Ea≊40 meV has been estimated. © 1996 American Institute of Physics.
Show PACS
71.55.Eq III-V semiconductors
78.55.Cr III-V semiconductors
78.66.Fd III-V semiconductors

High quality epitaxial Si grown by a simple low pressure chemical vapor deposition at 550 °C

Albert Chin, B. C. Lin, and W. J. Chen

Appl. Phys. Lett. 69, 1617 (1996); http://dx.doi.org/10.1063/1.117049 (3 pages) | Cited 7 times

Full Text: | Download PDF

Show Abstract
We have designed a simple‐hot wall low pressure chemical vapor deposition (LPCVD) system to grow high quality epitaxial Si films from 550 to 900 °C. The epitaxial film has been examined by scan electron microscopy for surface morphology, and by x‐ray diffraction and cross‐sectional transmission electron microscopy for crystallinity. Its quality has been found comparable to that of the substrate. Reduction of moisture and oxygen in the ambient is critical to the success of the growth at low temperatures. A combination of a leak‐tight LPCVD reactor, a high flow rate of 61/min of H2 purge, and a pre‐bake at high temperature of 950 °C has been used to achieve the reduction of moisture and oxygen. Degraded films form with increasing full width at half maximum of x‐ray diffraction peak when a pre‐bake at lower temperature is used. © 1996 American Institute of Physics.
Show PACS
68.55.-a Thin film structure and morphology
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
68.37.Hk Scanning electron microscopy (SEM) (including EBIC)
68.37.Lp Transmission electron microscopy (TEM)

Visible photoluminescence from porous GaAs

P. Schmuki, D. J. Lockwood, H. J. Labbé, and J. W. Fraser

Appl. Phys. Lett. 69, 1620 (1996); http://dx.doi.org/10.1063/1.117050 (3 pages) | Cited 50 times

Full Text: | Download PDF

Show Abstract
Porous GaAs was formed electrochemically on n‐type GaAs(100) in a 0.1 M HCl electrolyte. Scanning electron microscopy revealed feature sizes of the porous structure in the micrometer to nanometer range. The optical properties of the porous material were characterized by photoluminescence (PL) measurements at 295 K. Compared with untreated GaAs, a shift down of the ‘‘infrared’’ PL maximum to ∼840 nm can be observed. An additional ‘‘green’’ PL peak occurs at ∼540 nm that in some samples is readily visible to the naked eye. The ‘‘green’’ and the ‘‘infrared’’ PL are ascribed to quantum confinement effects in GaAs nano‐ and microcrystallites, respectively. © 1996 American Institute of Physics.
Show PACS
78.55.Mb Porous materials
82.45.-h Electrochemistry and electrophoresis

Determination of crystallite propagation in laser annealed amorphous silicon by normal incidence spectral reflectance

G. Williams, D. Sands, R. M. Geatches, and K. J. Reeson

Appl. Phys. Lett. 69, 1623 (1996); http://dx.doi.org/10.1063/1.117051 (3 pages) | Cited 11 times

Full Text: | Download PDF

Show Abstract
Analysis of normal incidence spectral reflectivity of excimer laser annealed α‐Si:H shows that the annealed material can be modeled as a stratified system comprising a large‐grained polycrystalline layer, a fine grained polycrystalline layer, and residual amorphous silicon in agreement with transmission electron microscopy. Optically, the large‐grained poly‐Si behaves as single‐crystal silicon and the fine‐grained material is modeled, using effective medium theory, as a mixture of single‐crystal silicon and amorphous silicon. © 1996 American Institute of Physics.
Show PACS
78.66.Jg Amorphous semiconductors; glasses
68.37.Hk Scanning electron microscopy (SEM) (including EBIC)
68.37.Lp Transmission electron microscopy (TEM)
61.43.Dq Amorphous semiconductors, metals, and alloys

Microwave surface resistance of YBa2Cu3Cu3O7−x films on polycrystalline ceramic substrates with textured buffer layers

A. T. Findikoglu, S. R. Foltyn, P. N. Arendt, J. R. Groves, Q. X. Jia, E. J. Peterson, X. D. Wu, and D. W. Reagor

Appl. Phys. Lett. 69, 1626 (1996); http://dx.doi.org/10.1063/1.117052 (3 pages) | Cited 9 times

Full Text: | Download PDF

Show Abstract
We have used a parallel‐plate resonator technique to measure the microwave surface resist‐ ance Rs of YBa2Cu3O7−x (YBCO) films on buffered ceramic substrates at around 10 GHz, and studied the correlation between their Rs and materials properties. A 0.4‐μm‐thick YBCO film (with an in‐plane mosaic spread of 7°) grown on a polycrystalline alumina substrate with an ion‐beam‐assisted‐deposited yttria‐stabilized zirconia buffer layer showed an Rs of 1.89 mΩ at 76 K and 0.21 mΩ at 4 K. We have observed a strong correlation between the Rs of the samples and the in‐plane mosaic spread of the YBCO films. This correlation can be explained qualitatively in terms of a simple model in which the weak links between the grains of the YBCO film form an electrical network of Josephson junctions.
Show PACS
74.78.-w Superconducting films and low-dimensional structures
74.78.Fk Multilayers, superlattices, heterostructures
74.25.N- Response to electromagnetic fields
81.15.Jj Ion and electron beam-assisted deposition; ion plating

Observation of ion gettering effects in high‐temperature superconducting oxide material

S. H. Hong, M. L. Chen, J. Baniecki, Q. Y. Ma, H. A. Wang, and R. W. Odom

Appl. Phys. Lett. 69, 1629 (1996); http://dx.doi.org/10.1063/1.117053 (2 pages) | Cited 2 times

Full Text: | Download PDF

Show Abstract
Ion gettering effect has been observed in high‐temperature superconducting YBa2Cu3O7 material. Silicon ions were implanted into the material and subsequent high‐temperature annealing produced ion movement from a low concentration region to a higher concentration region where the damage of the crystal structure is severe. This gettering effect could be used to make a superconductor‐nonsuperconductor‐superconductor trilayer structure within a single YBCO film. © 1996 American Institute of Physics.
Show PACS
74.72.-h Cuprate superconductors
61.72.Yx Interaction between different crystal defects; gettering effect

High energy resolution x‐ray detection based on a coupled Fiske cavity and Josephson junction oscillator

S. N. Song, S. R. Maglic, C. D. Thomas, M. P. Ulmer, and J. B. Ketterson

Appl. Phys. Lett. 69, 1631 (1996); http://dx.doi.org/10.1063/1.117054 (3 pages) | Cited 1 time

Full Text: | Download PDF

Show Abstract
We describe the use of a miniature microwave Fiske cavity coupled to a Josephson junction oscillator to monitor the dynamic quasiparticle population created in the surrounding superconductor by incident x rays. An expression is obtained for the phase velocities of the TM modes supported by this structure. The design has the advantage of being inherently thick—sufficient to completely absorb low energy x rays and is potentially scalable to a pixilated device with a pixel size 50 μm in linear dimension. The device represents an alternative strategy to implement the dynamic microwave absorption approach suggested by Gulian and Van Vechten and subsequent variations. © 1996 American Institute of Physics.
Show PACS
85.25.Cp Josephson devices
07.85.Fv X- and γ-ray sources, mirrors, gratings, and detectors

Shunted bicrystal Josephson junctions arrays for voltage standards

A. M. Klushin, W. Prusseit, E. Sodtke, S. I. Borovitskii, L. E. Amatuni, and H. Kohlstedt

Appl. Phys. Lett. 69, 1634 (1996); http://dx.doi.org/10.1063/1.117055 (3 pages) | Cited 21 times

Full Text: | Download PDF

Show Abstract
Series arrays of 365 shunted YBa2Cu3O7−x Josephson junctions on yttria‐stabilized zirconia bicrystals were investigated under microwave irradiation in the K‐band. Sub‐arrays of up to 39 junctions were synchronized to the external microwave power at a temperature of 15 K. Although there was a considerable spread in the critical currents of the junctions and in the microwave bias current distribution, a first Shapiro step with a height of 30% of the total critical current of the sub‐array was obtained by using an external shunt resistor, thus reducing the spread in normal resistances to 5%. Such high‐Tc cryoelectronic circuits are applicable for voltage standards and precision digital‐analog converters. © 1996 American Institute of Physics.
Show PACS
85.25.Cp Josephson devices
74.50.+r Tunneling phenomena; Josephson effects
06.20.F- Units and standards
74.72.-h Cuprate superconductors

Determining the absolute value of penetration depth of large area films

Ju Young Lee, Young Hwan Kim, Taek‐Sang Hahn, and Sang Sam Choi

Appl. Phys. Lett. 69, 1637 (1996); http://dx.doi.org/10.1063/1.117056 (3 pages) | Cited 8 times

Full Text: | Download PDF

Show Abstract
We report a method that allows the measurement of the absolute size of the magnetic penetration depth λ(T) of large area YBa2Cu3O7−δ films using the two‐coil method where a YBa2Cu3O7−δ film is overlapped with a 1‐μm‐thick Pb film equivalent in size placed in the gap between the drive and receive coil. The drive coil has fewer counter turns on the top section than the bottom, which is closer to the film, so the film’s edge current would be suppressed and the accuracy that depends on geometry is greatly improved. The transition of the Pb film causes a steplike portion in the mutual inductance M(T) graph and the resultant step height leads to the absolute value of λ. © 1996 American Institute of Physics.
Show PACS
74.25.N- Response to electromagnetic fields
74.78.-w Superconducting films and low-dimensional structures

Fabrication of n‐doped magnetic semiconductor heterostructures

I. Smorchkova and N. Samarth

Appl. Phys. Lett. 69, 1640 (1996); http://dx.doi.org/10.1063/1.117442 (3 pages) | Cited 18 times

Full Text: | Download PDF

Show Abstract
We demonstrate the introduction of high carrier densities into two and three‐dimensional magnetic semiconductor heterostructures that contain large local concentrations of magnetic moments. The use of (ZnSe)m−f(MnSe)f digital alloys readily allows the fabrication of epilayer samples of moderate Mn composition with carrier concentrations up to ∼1019 cm−3. Modulation doping of ZnSe/Zn1−x−yCdyMnxSe quantum wells enables the fabrication of a 2‐D electron gas confined within the magnetic region with sheet concentrations up to ∼6×1011 cm−2. © 1996 American Institute of Physics.
Show PACS
75.50.Pp Magnetic semiconductors
72.15.Rn Localization effects (Anderson or weak localization)
73.40.-c Electronic transport in interface structures

Epitaxial growth of cubic Laves phase intermetallic compounds (YCo2, TbCo2) and new epitaxial relationship between fcc (111) and bcc (110)

F. Robaut, S. Jaren, N. Cherief‐Benbrahim, and C. Meyer

Appl. Phys. Lett. 69, 1643 (1996); http://dx.doi.org/10.1063/1.117443 (3 pages) | Cited 7 times

Full Text: | Download PDF

Show Abstract
YCo2 and TbCo2 Laves phase compounds were epitaxially grown on (110) W buffer layers by pulsed laser deposition at a base pressure of 5×10−10 Torr and a substrate temperature of 500 °C. The films were characterized in situ by reflection high‐energy electron diffraction, and after deposition by grazing‐incidence x‐ray diffraction and scanning electron microscopy. The relative orientation of the RCo2(111), where R=Y or Tb, and the W(110) planes was found to be unlike any previously observed relationship between fcc and bcc materials. Two in‐plane crystallographic domains of RCo2(111) have been pointed out and are discussed in terms of geometrical lattice matching. © 1996 American Institute of Physics.
Show PACS
68.55.-a Thin film structure and morphology
61.05.cm X-ray reflectometry (surfaces, interfaces, films)
81.15.Fg Pulsed laser ablation deposition
75.50.Cc Other ferromagnetic metals and alloys

Organic insulating films of nanometer thicknesses

D. Vuillaume, C. Boulas, J. Collet, J. V. Davidovits, and F. Rondelez

Appl. Phys. Lett. 69, 1646 (1996); http://dx.doi.org/10.1063/1.117444 (3 pages) | Cited 48 times

Full Text: | Download PDF

Show Abstract
It is demonstrated that monolayers of organic molecules (long chain hydrocarbons) as thin as 1.9 nm, deposited by the self‐assembly technique on silicon, form high performance electrically insulating barriers. Their properties are compared with those of silicon dioxide. Leakage current densities through the organic monolayers of the order of 10−8–10−7A/cm2 have been obtained. These values are 4–5 decades lower than those for silicon dioxide of equivalent thickness. Larger tunneling barriers for organic monolayers than for silicon dioxide explain these results. © 1996 American Institute of Physics.
Show PACS
73.61.Ph Polymers; organic compounds
77.55.-g Dielectric thin films
Page 2 of 2 Pages Previous Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close