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30 Jul 1990

Volume 57, Issue 5, pp. 419-526

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Modulation‐doped AlInAs/InP heterostructures grown by organometallic vapor phase epitaxy

Leye Aina, Mike Mattingly, and Bob Potter

Appl. Phys. Lett. 57, 492 (1990); http://dx.doi.org/10.1063/1.103630 (2 pages) | Cited 6 times

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We have grown modulation‐doped AlInAs/InP heterostructures with two‐dimensional electron gases. Hall measurements and Shubnikov‐de Haas oscillations observed in these heterostructures yield electron mobilities as high as 26000, 9000, 2300 cm2/V s at 2, 77, and 300 K, with electron concentrations as high as 1.5×1012 cm−2. These results demonstrate the potential of the AlInAs/InP heterostructure for power microwave applications.
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72.20.Fr Low-field transport and mobility; piezoresistance
72.80.Ey III-V and II-VI semiconductors
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)

Metalorganic vapor phase epitaxial growth of high quality InGaAs on InP using tertiarybutylarsine

M. I. Abdalla, D. G. Kenneson, W. Powazinik, and E. S. Koteles

Appl. Phys. Lett. 57, 494 (1990); http://dx.doi.org/10.1063/1.103631 (3 pages) | Cited 1 time

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We report the growth by low‐pressure metalorganic vapor phase epitaxy of lattice‐matched InGaAs on InP substrates using tertiarybutylarsine as the arsenic source. The grown layers are uniform in composition and are consistently n type with low background carrier concentrations (2–3×1015/cm3). Room‐temperature mobility as high as 11 200 cm2/V s with a corresponding 77 °K mobility of 57 000 cm2/V s are measured. Photoluminescence gave a strong narrow peak with a full width half maximum=3.1 meV, with no evidence of carbon incorporation.
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81.15.Kk Vapor phase epitaxy; growth from vapor phase
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
78.55.Cr III-V semiconductors

Spatial resolution of the capacitance‐voltage profiling technique on semiconductors with quantum confinement

E. F. Schubert, R. F. Kopf, J. M. Kuo, H. S. Luftman, and P. A. Garbinski

Appl. Phys. Lett. 57, 497 (1990); http://dx.doi.org/10.1063/1.103632 (3 pages) | Cited 41 times

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The spatial resolution of the capacitance‐voltage profiling technique on semiconductors with one‐dimensional quantum confinement is shown to be given by the spatial extent of the wave function. The Debye length limitation does not apply. Capacitance‐voltage profiles on δ‐doped GaAs of density 4–4.5×1012 cm−2 exhibit widths of 20 and 48 Å for p‐ and n‐type impurities, respectively. The profiles agree with the theoretical resolution function and with Be and Si profiles measured by secondary‐ion mass spectroscopy. It is further shown that the saturation of the free‐carrier density of highly Si δ‐doped GaAs grown by molecular beam epitaxy is due to inactive Si impurities
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07.50.-e Electrical and electronic instruments and components
61.72.U- Doping and impurity implantation
61.72.sd Impurity concentration
61.72.sh Impurity distribution
61.72.sm Impurity gradients
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties

Humidity‐induced room‐temperature decomposition of Au contacted indium phosphide

Navid S. Fatemi and Victor G. Weizer

Appl. Phys. Lett. 57, 500 (1990); http://dx.doi.org/10.1063/1.103633 (3 pages) | Cited 2 times

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We have found that Au‐contacted InP is chemically unstable at room temperature in a humid ambient due to the leaching action of indium nitrate islands that continually remove In from the contact metallization and thus, in effect, from the InP substrate. While similar appearing islands form on Au‐contacted GaAs, that system appears to be stable since leaching of the group III element does not take place.
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73.40.Ns Metal-nonmetal contacts
68.35.Fx Diffusion; interface formation
84.60.Jt Photoelectric conversion

Long‐wavelength infrared detection in a Kastalsky‐type superlattice structure

Byungsung O, J.‐W. Choe, M. H. Francombe, K. M. S. V. Bandara, D. D. Coon, Y. F. Lin, and W. J. Takei

Appl. Phys. Lett. 57, 503 (1990); http://dx.doi.org/10.1063/1.103634 (3 pages) | Cited 16 times

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The first successful demonstration of long‐wavelength infrared (LWIR) detection with a Kastalsky‐type AlGaAs/GaAs superlattice structure is reported. The experimental response band of the detector is centered near 10 μm in very good agreement with the theoretical response band provided that electron‐electron interactions are taken into account. The detector operates at significantly lower bias voltage than photoconductive multiple quantum well LWIR detectors. This could lead to important advantages in applications to photovoltaic detector arrays. The response at 83 K is about 50% of the response at 24 K. Optimization of the response, operating temperature, or bias voltage has not been carried out.
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85.60.Gz Photodetectors (including infrared and CCD detectors)
78.66.Fd III-V semiconductors
78.66.Hf II-VI semiconductors
73.50.Pz Photoconduction and photovoltaic effects

Transverse stress effect on the critical current of jelly‐roll multifilamentary Nb3Al wires

Dimitris Zeritis, Toshinari Ando, Yoshikazu Takahashi, Masataka Nishi, Hideo Nakajima, and Susumu Shimamoto

Appl. Phys. Lett. 57, 506 (1990); http://dx.doi.org/10.1063/1.104241 (2 pages) | Cited 3 times

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Experiments were conducted to determine the transverse stress sensitivity of the critical current (Ic) of jelly‐roll multifilamentary Nb3Al wires at 8 and 12 T. For comparison, similar experiments were conducted on bronze‐process (NbTi)3Sn wires. At 12 T and under a transverse compressive stress of 150 MPa−conditions expected in fusion magnets−the Ic degradation of the Nb3Al specimen was ∼20% vs ∼65% for the (NbTi)3Sn specimen. The intrinsic superiority of Nb3Al over (NbTi)3Sn with regard to transverse compressive stress is thus clear. There is optimism that Nb3Al will eventually become a useful superconductor for large‐scale, high‐field applications.
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74.25.Sv Critical currents
74.25.N- Response to electromagnetic fields
74.70.Ad Metals; alloys and binary compounds (including A15, MgB2, etc.)
85.25.Qc Superconducting surface acoustic wave devices and other superconducting devices

Clean grain boundaries and weak links in high Tc superconducting YBa2Cu3O7−x thin films

D. H. Shin, J. Silcox, S. E. Russek, D. K. Lathrop, B. Moeckly, and R. A. Buhrman

Appl. Phys. Lett. 57, 508 (1990); http://dx.doi.org/10.1063/1.104242 (3 pages) | Cited 32 times

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It is demonstrated that polycrystalline thin films of high Tc superconducting YBa2Cu3O7−x can be grown with clean grain boundaries, i.e., without a boundary layer of segregation or different phase. In clean stoichiometric samples, angular misorientations of grains may be the origin of weak link behavior. High‐resolution scanning transmission electron microscope images of films grown on ZrO2 and MgO by reactive evaporation, reactive sputtering, and laser ablation show atomic lattice images of clean grain boundaries. X‐ray microanalysis with a 10 Å spatial resolution also indicates no composition deviation at the grain boundaries. Grain sizes and epitaxial relations of samples prepared by different methods are characterized.
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74.78.-w Superconducting films and low-dimensional structures
74.50.+r Tunneling phenomena; Josephson effects
74.25.Sv Critical currents
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy

Equilibrium oxygen potential for the decomposition of YBa2Cu4O8

Tom Mathews and K. T. Jacob

Appl. Phys. Lett. 57, 511 (1990); http://dx.doi.org/10.1063/1.103635 (3 pages) | Cited 6 times

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On lowering the chemical potential of diatomic oxygen, the compound YBa2Cu4O8 was found to decompose into a mixture of YBa2Cu3O6+x and CuO. The equilibrium oxygen potential corresponding to this decomposition has been measured from 870 to 1150 K using a solid‐state cell incorporating yttria‐stabilized zirconia as the solid electrolyte and pure oxygen at a pressure of 1.01×105 Pa as the reference electrode: Pt, O′2‖YBa2Cu4O8+YBa2Cu3O6+x+CuO∥(Y2O3) ZrO2∥O2(1.01×105 Pa), Pt. The low oxygen potential boundary for the stability of YBa2Cu4O8 can be represented by ΔμO2=−238 900+207.7 T(±800) J mol−1. At the standard pressure of oxygen (1.01×105 Pa) the decomposition occurs at 1150 K.
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82.60.Hc Chemical equilibria and equilibrium constants
64.70.K- Solid-solid transitions
74.25.Bt Thermodynamic properties

Tests of a superconducting rf quadrupole device

J. R. Delayen and K. W. Shepard

Appl. Phys. Lett. 57, 514 (1990); http://dx.doi.org/10.1063/1.103636 (3 pages) | Cited 4 times

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High surface electric fields have been obtained in the first tests of a superconducting rf quadrupole device. The rf quadrupole fields were generated between niobium vanes 6.5 cm in length, with an edge radius of 2 mm, and with a beam aperture of 6 mm diameter. In tests at 4.2 K, the 64 MHz device operated cw at peak surface electric fields of 128 MV/m. Virtually no electron loading was observed at fields below 100 MV/m. It was possible to operate at surface fields of 210 MV/m in pulses of 1 ms duration using a 2.5 kW rf source. For the vane geometry tested, more than 10 square centimeters of surface support a field greater than 90% of the peak field. The present result indicates that electric fields greater than 100 MV/m can be obtained over an appreciable area, sufficient for some accelerator applications. It also shows that superconducting rf technology may provide an extended range of options for rf quadrupole design.
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07.50.-e Electrical and electronic instruments and components
85.25.Qc Superconducting surface acoustic wave devices and other superconducting devices
74.25.N- Response to electromagnetic fields
29.20.Ej Linear accelerators

Anisotropic transport and cation disorder in superconducting Tl2Ca2Ba2Cu3Ox single crystals

C. P. Tigges, E. L. Venturini, J. F. Kwak, B. Morosin, R. J. Baughman, and D. S. Ginley

Appl. Phys. Lett. 57, 517 (1990); http://dx.doi.org/10.1063/1.104243 (3 pages) | Cited 4 times

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We have measured for the first time the temperature‐dependent anisotropic resistivity of several Tl2Ca2Ba2Cu3Ox single crystals. The resistivity ratio between the c axis and the a‐b plane orientations in the best crystals is approximately 60 at room temperature. Resistivity data indicate substantial differences in both Tc and the transition width of nominal Tl2Ca2Ba2Cu3Ox plates grown from two different melt compositions. A Tl‐O and CuO‐rich flux yielded approximately stoichiometric plates with sharp transitions beginning near 113 K, while a Tl‐O‐rich flux produced plates containing more Tl and less Ba with broad transitions starting near 103 K. These data demonstrate the extreme sensitivity of the superconductivity to cation site disorder in the Tl‐Ca‐Ba‐Cu‐O system.
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74.70.-b Superconducting materials other than cuprates
81.40.Rs Electrical and magnetic properties related to treatment conditions
74.25.Sv Critical currents
74.62.Bf Effects of material synthesis, crystal structure, and chemical composition

YBa2Cu3O7−δ superconducting films with low microwave surface resistance over large areas

N. Newman, K. Char, S. M. Garrison, R. W. Barton, R. C. Taber, C. B. Eom, T. H. Geballe, and B. Wilkens

Appl. Phys. Lett. 57, 520 (1990); http://dx.doi.org/10.1063/1.104244 (3 pages) | Cited 42 times

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We demonstrate that in situ off‐axis sputtering from a composite target can reproducibly fabricate very high quality YBa2Cu3O7−δ films over large areas of deposition. A significant reduction in the microwave surface resistance, Rs, compared to many previously reported values is found. Rs values at 10 GHz were found to be as low as 20 μΩ at 4.2 K and 450 μΩ at 77 K. A systematic variation of several properties including the transition temperature, critical current density at high magnetic fields, and the c‐axis lattice parameter across the 3.8 cm×3.8 cm (14.5 cm2) deposition area was found.
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74.25.N- Response to electromagnetic fields
74.78.-w Superconducting films and low-dimensional structures
74.70.-b Superconducting materials other than cuprates

Large critical current densities in YBa2Cu3O7−x thin films made at high deposition rates

X. D. Wu, R. E. Muenchausen, S. Foltyn, R. C. Estler, R. C. Dye, A. R. Garcia, N. S. Nogar, P. England, R. Ramesh, D. M. Hwang, T. S. Ravi, C. C. Chang, T. Venkatesan, X. X. Xi, Q. Li, et al.

Appl. Phys. Lett. 57, 523 (1990); http://dx.doi.org/10.1063/1.104245 (3 pages) | Cited 33 times

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Critical current densities (Jc) in YBa2Cu3O7−x films made at deposition rates from 0.1 to 14.5 nm/s (∼50 μm/h) were measured using a direct transport method. As the deposition rate was increased by two orders of magnitude, the films exhibited no marked degradation in current carrying capability with Jc of ∼4×106 A/cm2 at 77 K and zero field. Jc for all the films showed similar behavior under a magnetic field up to 8 T, although extra structural defects were found in the films deposited at the higher rates. The results from this experiment indicate the feasibility for coating wires, tapes, and other macroscopic shapes with high Tc superconductors using proper vapor deposition techniques.
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74.25.Sv Critical currents
74.62.Bf Effects of material synthesis, crystal structure, and chemical composition
74.78.-w Superconducting films and low-dimensional structures
68.55.-a Thin film structure and morphology
FREE

Erratum: Electrical properties of hydrogenated diamond [Appl. Phys. Lett. 56, 1454 (1990)]

Sacharia Albin and Linwood Watkins

Appl. Phys. Lett. 57, 526 (1990); http://dx.doi.org/10.1063/1.103637 (1 page)

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Abstract Unavailable
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72.80.Sk Insulators
72.80.Ng Disordered solids
73.61.Cw Elemental semiconductors
73.61.Jc Amorphous semiconductors; glasses
73.61.Le Other inorganic semiconductors
73.61.Ng Insulators
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