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 Apr 1993

Volume 62, Issue 17, pp. 2003-2145

Page 2 of 2 Pages Previous Page | Jump to Page

Valence band offset of GaAs/GaAs0.68P0.32 multiple quantum wells

W. Shan, S. J. Hwang, J. J. Song, H. Q. Hou, and C. W. Tu

Appl. Phys. Lett. 62, 2078 (1993); http://dx.doi.org/10.1063/1.109484 (3 pages) | Cited 6 times

Full Text: | Download PDF

Show Abstract
Low‐temperature photoluminescence measurements have been performed under hydrostatic pressure on GaAs/GaAs0.68P0.32 strained multiple quantum well samples grown by gas‐source molecular beam epitaxy. The pressure induced crossover of the first confined electron state in the GaAs wells against the conduction band (001) X minima in the GaAs0.68P0.32 barriers has been observed, which allows a direct spectroscopic determination of the valence band offset for the heterostructure. As the result we obtain the unstrained valence band offset as 0.09±0.02 eV, which corresponds to an approximate 77:23 distribution of the energy gap difference in the conduction and valence bands, respectively, for the GaAs/GaAs0.68P0.32 system.
Show PACS
78.66.Fd III-V semiconductors
78.55.Cr III-V semiconductors
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems

Hydrogen enhancement of silicon thermal donor formation

C. D. Lamp and D. J. James

Appl. Phys. Lett. 62, 2081 (1993); http://dx.doi.org/10.1063/1.109485 (3 pages) | Cited 8 times

Full Text: | Download PDF

Show Abstract
Oxygen‐related thermal donor formation in Czochralski silicon is characterized by the capacitance‐voltage and deep level transient spectroscopy techniques as a function of 450 °C anneal time following hydrogenation. Increases in the formation rate and number of thermal donor (TD) defects found after hydrogenation are reported. This study finds an increase in TD+/++ concentration in the near‐surface region at short anneal times, but at longer times an elevated concentration was not observed. No acceleration through the sequence of thermal donor defects was detected. This fails to support the model of hydrogen lowering the barrier to oxygen diffusion and accelerating the TDn→TDn+1 transitions. This study does, however, support a model in which the hydrogen increases the available thermal donor core sites.
Show PACS
71.55.Cn Elemental semiconductors
61.72.Cc Kinetics of defect formation and annealing
61.72.J- Point defects and defect clusters

Reactive chemical beam etching of InP inside a chemical beam epitaxial growth chamber using phosphorus trichloride

W. T. Tsang, R. Kapre, and P. F. Sciortino

Appl. Phys. Lett. 62, 2084 (1993); http://dx.doi.org/10.1063/1.109486 (3 pages) | Cited 15 times

Full Text: | Download PDF

Show Abstract
We have extended the capability and versatility of a chemical beam epitaxial (CBE) system by demonstrating reactive chemical beam etching (RCBE) of InP using phosphorus trichloride (PCl3) as the gaseous etching beam injected directly into the growth chamber. This permits instant switching from etching to growth (and vice versa) in the same run for the first time in CBE. We investigate RCBE of InP at various substrate temperatures between ∼400 and 580 °C, under different PCl3 fluences, and etching conditions. Excellent surface morphology was obtained at high temperatures (≳530–570 °C) and under an etching rate of ≲6 Å/s. We also found that upon addition of trimethylindium flow equivalent to a growth rate of 1 Å/s during RCBE a dramatic improvement in surface morphology was obtained even at a high net etching rate of 10 Å/s. The surface morphology obtained under such conditions is indistinguishable from that of the original substrate surface.
Show PACS
81.65.-b Surface treatments
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces

Photon‐induced anisotropic oxidation along p‐n junctions in AlxGa1−xAs‐GaAs quantum well heterostructures

S. A. Maranowski, N. Holonyak, T. A. Richard, and F. A. Kish

Appl. Phys. Lett. 62, 2087 (1993); http://dx.doi.org/10.1063/1.109487 (3 pages) | Cited 10 times

Full Text: | Download PDF

Show Abstract
Data are presented demonstrating, in ‘‘wet’’ oxidation, anisotropic oxide formation at p‐n junction edges in AlxGa1−xAs‐GaAs quantum well heterostructures (QWHs). The QWH high gap AlxGa1−xAs upper confining layer is oxidized via H2O vapor at elevated temperatures (425–525 °C). The higher energy portion of ‘‘blackbody’’ radiation (the furnace ambient) at these temperatures generates sufficient electron‐hole pairs to drive anodic oxidation at the edge of a QWH p‐n junction. The anisotropic oxidation, on the p‐type side of the junction, and possible reaction mechanisms are described.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
81.65.-b Surface treatments
73.50.Pz Photoconduction and photovoltaic effects
82.50.-m Photochemistry

Generation mechanisms of crystal defects in arsenic and phosphorus implanted silicon devices

H. L. Tsai, S. M. Hemming, R. H. Eklund, and H. H. Hosack

Appl. Phys. Lett. 62, 2090 (1993); http://dx.doi.org/10.1063/1.109488 (3 pages) | Cited 3 times

Full Text: | Download PDF

Show Abstract
Arsenic and phosphorus are often implanted into silicon for localized doping during the processing of integrated circuits. The implant damages the silicon lattice, resulting in crystal defects during annealing. Crystal defects observed by transmission electron microscopy (TEM) appear at three different locations in patterned devices. The mechanisms underlying the generation of these defects are presented and discussed, based on an extensive study under various process conditions. These mechanisms form the basis for eliminating/reducing defects in arsenic or phosphorus implanted silicon devices.
Show PACS
61.72.uf Ge and Si
61.72.Cc Kinetics of defect formation and annealing
61.80.Jh Ion radiation effects

p‐type conduction in pyrite single crystals prepared by chemical vapor transport

O. Blenk, E. Bucher, and G. Willeke

Appl. Phys. Lett. 62, 2093 (1993); http://dx.doi.org/10.1063/1.109489 (3 pages) | Cited 5 times

Full Text: | Download PDF

Show Abstract
Pyrite (FeS2) single crystals have been prepared by chemical vapor transport from the elements, using additional phosphorus as a possible dopant source. Hall as well as thermoprobe measurements clearly indicated p‐type conduction. Carrier concentrations of between 1 and 8×1018 cm−3 and Hall mobilities of 0.42–0.76 cm2/V s were deduced.  
Show PACS
72.80.Ga Transition-metal compounds
61.72.up Other materials
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy

Long range disordering of GaAs‐AlGaAs multiquantum wells by isoelectronic antimony implants

E. V. K. Rao, M. Juhel, Ph. Krauz, Y. Gao, and H. Thibierge

Appl. Phys. Lett. 62, 2096 (1993); http://dx.doi.org/10.1063/1.109490 (3 pages) | Cited 6 times

Full Text: | Download PDF

Show Abstract
We show here for the first time that the width of implant damage disordered regions in GaAs‐AlGaAs MQWs can be extended to depths as far as ∼30 times the implant projected range (Rp). This is accomplished by performing room‐temperature implants of isoelectronic Sb+ (Rp∼0.09 μm) in thick 130 period multiquantum well structures consisting of alternate layers of ∼100 Å GaAs (Lz) and ∼100 Å Al0.3Ga0.7As (Lb). Subsequent to high temperature (850 °C) and long duration (up to 4 h) furnace anneals, the disordering has been monitored using photoluminescence spectroscopy and secondary ion mass spectroscopy for depth dependence. The data is tentatively explained assuming a long range migration of defects both during implantation and annealing processes.
Show PACS
61.80.Jh Ion radiation effects
61.72.Cc Kinetics of defect formation and annealing
61.72.uj III-V and II-VI semiconductors

Carbon doping for AlGaAs/GaAs heterojunction bipolar transistors by molecular‐beam epitaxy

Hiroshi Ito, Osaake Nakajima, and Tadao Ishibashi

Appl. Phys. Lett. 62, 2099 (1993); http://dx.doi.org/10.1063/1.109491 (3 pages) | Cited 8 times

Full Text: | Download PDF

Show Abstract
Carbon doping in GaAs is investigated using solid‐source molecular‐beam epitaxy. The proportion of inactive C atoms in GaAs layers is found to increase when the free‐carrier concentration is higher than about 1018/cm3. The current gain of AlGaAs/GaAs heterojunction bipolar transistors decreases rapidly with increasing base doping. The gradient of this tendency is much steeper than for inverse base doping, indicating the introduction of additional nonradiative recombination centers in heavily doped regions. A high current gain of 300 is achieved with a base doping of 2.5×1018/cm3.
Show PACS
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
61.72.uj III-V and II-VI semiconductors
85.30.Pq Bipolar transistors
72.80.Ey III-V and II-VI semiconductors

Epitaxy enhancement of β‐FeSi2 grown by ion beam assisted deposition

A. Terrasi, S. Ravesi, M. G. Grimaldi, and C. Spinella

Appl. Phys. Lett. 62, 2102 (1993); http://dx.doi.org/10.1063/1.109465 (3 pages) | Cited 8 times

Full Text: | Download PDF

Show Abstract
Iron silicide layers have been grown by 200 eV Ar+ beam assisted deposition of Fe onto 〈001〉 Si single crystals maintained at high temperatures. Polycrystalline FeSi has been formed at T=400 °C while partially epitaxial β‐FeSi2 was obtained after deposition at 500 °C. Samples have been analyzed by Rutherford backscattering spectroscopy and transmission electron microscopy. The main effects of the ion beam have been the reduction of the average grain size of the polycrystallites for both phases and the enhancement of the epitaxial fraction for the β‐FeSi2 phase. The role of the ion beam during the formation of the iron silicides has been discussed.
Show PACS
68.55.-a Thin film structure and morphology
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy

Terracing and step bunching in interfaces of molecular beam epitaxy‐grown (Al)GaAs multilayers

O. Albrektsen, H. P. Meier, D. J. Arent, and H. W. M. Salemink

Appl. Phys. Lett. 62, 2105 (1993); http://dx.doi.org/10.1063/1.109466 (3 pages) | Cited 7 times

Full Text: | Download PDF

Show Abstract
The growth terraces in molecular beam epitaxy‐grown AlxGa1−xAs multilayers are observed on the ultrahigh vacuum cleaved (110) cross‐sectional plane using scanning tunneling microscopy. Under regular growth conditions on 2° off oriented vicinal surfaces, we observe step bunching of 2–8 atomic layers and a corresponding extension of the terrace length instead of monolayer steps. These results demonstrate that the roughness of quantum confinement layers can be studied down to the atomic scale in a direct way.
Show PACS
68.37.Ef Scanning tunneling microscopy (including chemistry induced with STM)
68.37.Ps Atomic force microscopy (AFM)
68.37.Rt Magnetic force microscopy (MFM)
68.37.Uv Near-field scanning microscopy and spectroscopy
68.55.-a Thin film structure and morphology
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions

Green/yellow light emitting diodes from isoelectronically doped ZnSe quantum well structures

M. Hagerott, J. Ding, H. Jeon, A. V. Nurmikko, Y. Fan, L. He, J. Han, J. Saraie, R. L. Gunshor, C. G. Hua, and N. Otsuka

Appl. Phys. Lett. 62, 2108 (1993); http://dx.doi.org/10.1063/1.109467 (3 pages) | Cited 3 times

Full Text: | Download PDF

Show Abstract
Green/yellow emission has been obtained from ZnSe‐based pn junction heterostructures where Te is introduced as an isoelectronic center by planar doping of (Zn,Cd)Se quantum wells with ZnTe. The spectra show details which are directly related to the strong coupling of excitons to the lattice at the Te‐rich sites.
Show PACS
78.66.Hf II-VI semiconductors
78.40.Ha Other nonmetallic inorganics
85.60.Jb Light-emitting devices

Photoluminescence from stain‐etched polycrystalline Si thin films

A. J. Steckl, J. Xu, and H. C. Mogul

Appl. Phys. Lett. 62, 2111 (1993); http://dx.doi.org/10.1063/1.109468 (3 pages) | Cited 19 times

Full Text: | Download PDF

Show Abstract
Visible room‐temperature photoluminescence (PL) has been observed from stain‐etched polycrystalline Si thin films. Poly‐Si thin films deposited on oxidized Si and quartz substrates became porous (PoSi) after stain‐etching in a 1:3:5 solution of HF:HNO3:H2O. Under UV excitation, the stain‐etched doped and undoped poly‐Si films produce uniform orange‐red (∼650 nm) luminescence very similar to that obtained from stain‐etched crystalline Si substrates. Stained amorphous thin films did not exhibit photoluminescence. Luminescent patterns with sub‐micrometer (∼0.6 μm) dimensions have been obtained for the first time from PoSi produced from poly‐Si films.  
Show PACS
78.55.Hx Other solid inorganic materials

Effect of thermal resistivity on the catastrophic optical damage power density of AlGaInP laser diodes

Hiroaki Fujii, Yoshiyasu Ueno, and Kenji Endo

Appl. Phys. Lett. 62, 2114 (1993); http://dx.doi.org/10.1063/1.109469 (2 pages) | Cited 16 times

Full Text: | Download PDF

Show Abstract
We show that the low catastrophic optical damage power density observed for AlGaInP laser diodes (LDs) (1/2 to 1/2.9 that of AlGaAs LDs) is mainly attributable to the high thermal resistivities of the materials (5.5 times higher than for AlGaAs LDs) by using a thermal runaway model calculation.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.60.Mi Dynamical laser instabilities; noisy laser behavior
78.66.Fd III-V semiconductors

Helium‐excited reactive magnetron sputtering for stress‐free silicon nitride films

Iwao Sugimoto and Satoko Nakano

Appl. Phys. Lett. 62, 2116 (1993); http://dx.doi.org/10.1063/1.109444 (3 pages) | Cited 7 times

Full Text: | Download PDF

Show Abstract
Compressive stress in reactively magnetron‐sputtered silicon nitride films can be considerably reduced by helium‐excited rf plasma. Plasma emission spectroscopy reveals that plasma consisting of the gas ratio of He/N2=11.5 preferentially produces the highly reactive N2+ ions through collisional ionization by the metastably excited helium atoms and suppresses the generation of energetic particles. Increasing plasma reactivity for Si—N bond formation and reduction of the peening effect both effectively reduce the resulting film stress.
Show PACS
81.15.Cd Deposition by sputtering

Superconducting terahertz mixer using a transition‐edge microbolometer

D. E. Prober

Appl. Phys. Lett. 62, 2119 (1993); http://dx.doi.org/10.1063/1.109445 (3 pages) | Cited 115 times

Full Text: | Download PDF

Show Abstract
We present a new device concept for a mixer element for THz frequencies. This uses a superconducting transition‐edge microbridge biased at the center of its superconducting transition near 4.2 K. It is fed from an antenna or waveguide structure. Power from a local oscillator and a rf signal produce a temperature and resulting resistance variation at the difference frequency. The new aspect is the use of a very short bridge in which rapid (<0.1 ns) outdiffusion of hot electrons occurs. This gives large intermediate frequency (if) response. The mixer offers ≊4 GHz if bandwidth, ≊80 Ω rf resistive impedance, good match to the if amplifier, and requires only 1–20 nW of local oscillator power. The upper rf frequency is determined by antenna or waveguide properties. Predicted mixer conversion efficiency is 1/8, and predicted double‐sideband receiver noise temperatures are 260 and 90 K for transition widths of 0.1 and 0.5 Tc, respectively.
Show PACS
07.57.Kp Bolometers; infrared, submillimeter wave, microwave, and radiowave receivers and detectors
84.30.Qi Modulators and demodulators; discriminators, comparators, mixers, limiters, and compressors
95.55.-n Astronomical and space-research instrumentation
85.25.Qc Superconducting surface acoustic wave devices and other superconducting devices

Absolute magnetic penetration depth of thin‐film niobium measured by fluxoid quantization

C. E. Cunningham, G. S. Park, B. Cabrera, and M. E. Huber

Appl. Phys. Lett. 62, 2122 (1993); http://dx.doi.org/10.1063/1.109446 (3 pages) | Cited 5 times

Full Text: | Download PDF

Show Abstract
The absolute magnetic penetration depth of a superconducting niobium film is measured using fluxoid quantization. Laser pulses drive part of a thin, planar niobium loop normal, changing its quantum fluxoid state. We determine the total inductance of the loop by measuring the coupling of the fluxoid to a superconducting quantum interference device at various loop temperatures. We fit the temperature dependence of the inductance data to the Bardeen–Cooper–Schrieffer (BCS) theory to determine the magnetic and kinetic inductances. The kinetic inductance is directly related to the penetration depth through the geometry of the loop, and the measured penetration depth agrees well with the BCS theory.  
Show PACS
74.25.N- Response to electromagnetic fields
74.20.Fg BCS theory and its development
74.78.-w Superconducting films and low-dimensional structures
74.70.Ad Metals; alloys and binary compounds (including A15, MgB2, etc.)

In situ preparation of YBa2Cu3Oy thin films without post‐oxygenation cooling using opposed‐targets magnetron sputtering

Hidekazu Teshima, Haruo Shimada, and Muneyuki Imafuku

Appl. Phys. Lett. 62, 2125 (1993); http://dx.doi.org/10.1063/1.109447 (3 pages) | Cited 1 time

Full Text: | Download PDF

Show Abstract
Superconducting YBa2Cu3Oy thin films have been successfully prepared in situ by the opposed‐targets magnetron sputtering method without introducing oxygen into the sputtering chamber after deposition. Although the films were cooled down under 1 atm of nitrogen atmosphere after deposition, they showed zero resistance Tc as high as 88 K with a relatively sharp transition width ΔTc (90%–10%) of 2 K. This suggests that the growing films contain enough oxygen to show superconductivity, in other words, the possibility of forming the orthorhombic structure during growth. Further, the films showed lower Tc at 83.5 K when they were cooled down under oxygen. This unexpected result can be explained by the overdoping of holes in the Cu‐O2 planes.
Show PACS
81.15.Cd Deposition by sputtering
74.78.-w Superconducting films and low-dimensional structures
74.72.-h Cuprate superconductors
74.62.Dh Effects of crystal defects, doping and substitution

Magnetic microscopy using a liquid nitrogen cooled YBa2Cu3O7 superconducting quantum interference device

R. C. Black, A. Mathai, F. C. Wellstood, E. Dantsker, A. H. Miklich, D. T. Nemeth, J. J. Kingston, and J. Clarke

Appl. Phys. Lett. 62, 2128 (1993); http://dx.doi.org/10.1063/1.109448 (3 pages) | Cited 65 times

Full Text: | Download PDF

Show Abstract
We have developed a magnetic flux microscope which uses a liquid nitrogen cooled thin‐film YBa2Cu3O7 dc superconducting quantum interference device (SQUID) to produce two‐dimensional images of magnetic fields. The instrument operates as a scanning probe microscope with a spatial resolution of about 80 μm and a field of view of about 100 mm2. The equivalent magnetic field noise in the SQUID ranges from 80 pT Hz−1/2 at 1 Hz to 20 pT Hz−1/2 at 1 kHz, yielding a field resolution of about 200 pT in our images. We have used the microscope to image magnetic domains in ferromagnetic samples, small currents flowing in fine wires, and trapped flux and diamagnetic susceptibility in superconducting thin films.
Show PACS
07.55.-w Magnetic instruments and components
75.70.Rf Surface magnetism
75.60.Ch Domain walls and domain structure

Fabrication conditions and superconducting properties of Ag‐sheathed Bi‐Sr‐Ca‐Cu‐O tapes prepared by partial melting and slow cooling process

K. Nomura, M. Seido, H. Kitaguchi, H. Kumakura, K. Togano, and H. Maeda

Appl. Phys. Lett. 62, 2131 (1993); http://dx.doi.org/10.1063/1.109449 (3 pages) | Cited 30 times

Full Text: | Download PDF

Show Abstract
Ag‐sheathed Bi2Sr2Ca1Cu2Ox(Bi‐2212) tapes with various oxide superconductor core (SC‐core) thicknesses, SC‐core ratios (SC‐core area to overall cross‐sectional area), and tape configurations were prepared by a partial melting and slow cooling process. For single‐core tapes the critical current density, Jc(core), for SC‐core, increases with decreasing SC‐core thickness, due to the highly aligned Bi‐2212 grains, and the highest Jc(core) of 1.4×105 A/cm2 at 4.2 K in 10 T is achieved at a core thickness of 15 μm. Furthermore, the Jc(core) increases with increasing SC‐core ratio (i.e., with decreasing Ag‐sheath thickness). From the practical point of view, high Jc(overall) as well as high critical current (Ic) is more important than Jc(core). This requirement is attained by the double‐tube method, which shows the highest Jc(overall) value of 3.0×104 A/cm2 at 4.2 K in 10 T. In the tape fabrication process, the slow heating rate just below the partial melting becomes important, because oxygen released from the SC‐core during heating makes void swelling in the Ag sheath and leads to the degradation of Jc.
Show PACS
84.71.Mn Superconducting wires, fibers, and tapes
81.20.Ev Powder processing: powder metallurgy, compaction, sintering, mechanical alloying, and granulation
74.72.-h Cuprate superconductors
74.81.Bd Granular, melt-textured, amorphous, and composite superconductors

Origin of 1/f noise in Y1Ba2Cu3O7−x step‐edge dc SQUIDs

D. Grundler, R. Eckart, B. David, and O. Dössel

Appl. Phys. Lett. 62, 2134 (1993); http://dx.doi.org/10.1063/1.109450 (3 pages) | Cited 12 times

Full Text: | Download PDF

Show Abstract
We have fabricated Y1Ba2Cu3O7−x step‐edge junction dc superconducting quantum interference devices (SQUIDs) and characterized their noise performance. The current‐voltage characteristics of our SQUIDs are of resistively shunted junction type with critical current densities jc of about 104 A/cm2 and maximum flux to voltage transfer functions δV/δΦ of 20 μV/Φ0 at 77 K. We compare model predictions for 1/f noise in dc SQUIDs with experimental data and show that the frequency dependent noise in our devices results from critical current fluctuations of the Josephson junctions. A bias current reversing technique is effective in suppressing this noise contribution. A flux noise Φn of 80 μΦ0/Hz1/2 at 1 Hz and 77 K was measured on a dc SQUID with an inductance Ls of 60 pH.
Show PACS
85.25.Dq Superconducting quantum interference devices (SQUIDs)
72.70.+m Noise processes and phenomena
74.40.-n Fluctuation phenomena
74.72.-h Cuprate superconductors

SrTiO3 buffer layers and tunnel barriers for Ba‐K‐Bi‐O junctions

B. A. Baumert, J. Talvacchio, and M. G. Forrester

Appl. Phys. Lett. 62, 2137 (1993); http://dx.doi.org/10.1063/1.109451 (3 pages) | Cited 5 times

Full Text: | Download PDF

Show Abstract
Epitaxial SrTiO3 films were used as buffer layers and tunnel barriers for Ba0.6K0.4BiO3 (BKBO) films and tunnel junctions, respectively. In contrast to BKBO films grown directly on LaAlO3, films grown on SrTiO3 (001) buffer layers on LaAlO3 had a single (001) growth orientation, with Tc’s of 26 K and Δω=0.7°. These values are both equal to those obtained for growth on a SrTiO3 single crystal. A similar improvement was obtained for BKBO grown on SrTiO3‐buffered NdGaO3 substrates. Tunnel junctions consisting of BKBO(001)/SrTiO3/BKBO layers had substantial contributions to the gap voltage from both the base and top BKBO electrodes.  
Show PACS
68.55.-a Thin film structure and morphology
74.78.-w Superconducting films and low-dimensional structures
74.45.+c Proximity effects; Andreev reflection; SN and SNS junctions

New measurement techniques to determine magnetization and coercivity using a torque magnetometer

Jeen Hur and Sung‐Chul Shin

Appl. Phys. Lett. 62, 2140 (1993); http://dx.doi.org/10.1063/1.109452 (3 pages) | Cited 2 times

Full Text: | Download PDF

Show Abstract
We have developed new techniques to measure the magnetization and the coercivity of a uniaxial magnetic material using a torque magnetometer. The magnetization could be measured from the linear dependence at the low‐field regime in a plot of the torque versus the applied magnetic field, where the direction of the applied field was perpendicular to the uniaxial orientation. The coercivity could be obtained by taking the value of the applied field where the torque is zero, when the direction of the applied field was (180+δ) degrees from the uniaxial orientation. The techniques were applied to determine the magnetizations and the coercivities of several Co/Pd multilayer thin films. The results were confirmed to be similar within a 2% difference to those obtained by a vibrating sample magnetometer.
Show PACS
07.55.-w Magnetic instruments and components
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
75.70.Cn Magnetic properties of interfaces (multilayers, superlattices, heterostructures)

Focused ion beam direct deposition of gold

Shinji Nagamachi, Yasuhiro Yamakage, Hiromasa Maruno, Masahiro Ueda, Seiji Sugimoto, Masatoshi Asari, and Junzo Ishikawa

Appl. Phys. Lett. 62, 2143 (1993); http://dx.doi.org/10.1063/1.109453 (3 pages) | Cited 16 times

Full Text: | Download PDF

Show Abstract
Focused ion beam direct deposition has been developed as a new technique for making patterned metal film directly on substrates. The 20 keV Au+ ion beam is focused, deflected, and finally decelerated to 30–200 eV between the objective lens and substrate. The decelerated beam is deposited on the substrate at room temperature. The beam diameter can be tuned between 0.5 and 8 μm and the beam current varies from 40 pA to 10 nA, corresponding to the beam diameter. Current density was about 20 mA/cm2, so that the deposition rate in the beam spot was estimated about 0.02 μm/s. The purity of gold film was measured with Auger electron spectroscopy and contents of carbon and oxygen, undesirable impurities, were below detection limits. The resistivity was constant at 3.7±0.1 μΩ cm for deposition over the ion energy range of 34–194 eV.
Show PACS
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
Page 2 of 2 Pages Previous Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close