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26 Mar 2007

Volume 90, Issue 13, Articles (13xxxx)

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Appl. Phys. Lett. 90, 134101 (2007); http://dx.doi.org/10.1063/1.2679209 (3 pages)

S. Srinivasan, J. Hiller, B. Kabius, and O. Auciello
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Effect of nitrogen content in HfxTayN metal gate on work function and thermal stability of advanced metal-oxide-semiconductor devices

Ping-Hung Tsai, Kuei-Shu Chang-Liao, Tzu-Cheng Wang, Tien-Ko Wang, Chuen-Horng Tsai, and Chin-Lung Cheng

Appl. Phys. Lett. 90, 132101 (2007); http://dx.doi.org/10.1063/1.2716311 (3 pages) | Cited 2 times

Online Publication Date: 26 March 2007

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The effects of nitrogen composition in HfxTayN metal-gate electrodes and postmetal annealing (PMA) treatment on the electrical properties of metal-oxide-semiconductor (MOS) devices were investigated in this work. The work function of HfxTayN gate electrodes can be adjusted by incorporating various nitrogen contents. It is found that the HfxTayN metal gate with higher nitrogen content can achieve better electrical characteristics in terms of leakage current and reliability while with only a slight increase in equivalent-oxide-thickness value. The face that only slight variation on electrical characteristics of MOS device with HfxTayN gate electrodes is observed after various PMA temperatures designates the excellent thermal stability of HfxTayN gate electrodes. The present study indicates that HfxTayN is a promising metal-gate-electrode material for advanced MOS devices.
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85.30.Tv Field effect devices

Memory characteristics of Co nanocrystal memory device with HfO2 as blocking oxide

F. M. Yang, T. C. Chang, P. T. Liu, P. H. Yeh, Y. C. Yu, J. Y. Lin, S. M. Sze, and J. C. Lou

Appl. Phys. Lett. 90, 132102 (2007); http://dx.doi.org/10.1063/1.2716845 (3 pages) | Cited 31 times

Online Publication Date: 26 March 2007

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In this letter, the Co nanocrystals using SiO2 and HfO2 as the tunneling and the control dielectric with memory effect has been fabricated. A significant memory effect was observed through the electrical measurements. Under the low voltage operation of 5 V, the memory window was estimated to ∼ 1 V. The retention characteristics were tested to be robust. Also, the endurance of the memory device was not degraded up to 106 write/erase cycles. The processing of the structure is compatible with the current manufacturing technology of semiconductor industry.
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84.30.Sk Pulse and digital circuits
85.50.-n Dielectric, ferroelectric, and piezoelectric devices

Persistent photoconductivity in p-type ZnO(N) grown by molecular beam epitaxy

A. Y. Polyakov, N. B. Smirnov, A. V. Govorkov, A. I. Belogorokhov, E. A. Kozhukhova, A. V. Markov, A. Osinsky, J. W. Dong, and S. J. Pearton

Appl. Phys. Lett. 90, 132103 (2007); http://dx.doi.org/10.1063/1.2717089 (3 pages) | Cited 11 times

Online Publication Date: 26 March 2007

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Current transport mechanisms and persistent photoconductivity effects were studied in nitrogen-doped ZnO films grown by molecular beam epitaxy having p-type or n-type conductivity at 25 °C. In both types of samples the current flow is determined by the n-type channels surrounded by higher resistivity regions. The persistent photoconductivity wave form is reasonably described by the stretched-exponents-type expression, with only a slight temperature dependence of the characteristic decay time. The persistent photocurrent decay process is greatly accelerated by infrared illumination (threshold energy of the photons ∼ 1.4 eV). The results suggest that the Fermi level in the higher resistivity regions is pinned near Ev+1.9±0.1 eV and the height of the potential barrier for electrons in the n-type channels is around 1.4±0.1 eV.
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73.61.Ga II-VI semiconductors
72.40.+w Photoconduction and photovoltaic effects

Effects of the permanent dipoles of self-assembled monolayer-treated insulator surfaces on the field-effect mobility of a pentacene thin-film transistor

Yunseok Jang, Jeong Ho Cho, Do Hwan Kim, Yeong Don Park, Minkyu Hwang, and Kilwon Cho

Appl. Phys. Lett. 90, 132104 (2007); http://dx.doi.org/10.1063/1.2457776 (3 pages) | Cited 28 times

Online Publication Date: 27 March 2007

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In order to investigate the effects of permanent dipoles on insulator surfaces on the electrical properties of organic thin-film transistors, the authors fabricated insulators with various self-assembled monolayers and similar surface energies. Surprisingly, they found that the field-effect mobility of pentacene thin-film transistors increases by a factor of approximately 20 for insulators with an electron-withdrawing group. This remarkable increase in the field-effect mobility is due to the increase in the hole density of the insulator surface that arises from the increased band bending of the insulator/semiconductor interface.
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85.30.Tv Field effect devices

Valence band offset of InN/AlN heterojunctions measured by x-ray photoelectron spectroscopy

P. D. C. King, T. D. Veal, P. H. Jefferson, C. F. McConville, T. Wang, P. J. Parbrook, Hai Lu, and W. J. Schaff

Appl. Phys. Lett. 90, 132105 (2007); http://dx.doi.org/10.1063/1.2716994 (3 pages) | Cited 34 times

Online Publication Date: 27 March 2007

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The valence band offset of wurtzite-InN/AlN (0001) heterojunctions is determined by x-ray photoelectron spectroscopy to be 1.52±0.17 eV. Together with the resulting conduction band offset of 4.0±0.2 eV, a type-I heterojunction forms between InN and AlN in the straddling arrangement.
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71.20.Nr Semiconductor compounds
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
79.60.Bm Clean metal, semiconductor, and insulator surfaces

Solution-processable pentacene microcrystal arrays for high performance organic field-effect transistors

Wi Hyoung Lee, Do Hwan Kim, Yunseok Jang, Jeong Ho Cho, Minkyu Hwang, Yeong Don Park, Yong Hoon Kim, Jeong In Han, and Kilwon Cho

Appl. Phys. Lett. 90, 132106 (2007); http://dx.doi.org/10.1063/1.2717087 (3 pages) | Cited 39 times

Online Publication Date: 27 March 2007

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The authors report the fabrication of one-dimensional crystal arrays of triisopropylsilylethynyl pentacene (TIPS PEN) via simple drop casting on a tilted substrate. By pinning a solution droplet on the tilted substrate, an array of ribbon-shaped crystals aligned in the tilted direction was formed on the substrate. X-ray diffraction analysis revealed that these crystals were oriented in the crystal growth direction. A thin film transistor based on such an array of TIPS PEN crystals was found to have a high field-effect mobility of 0.3 cm2/V s, which results from the directed organization of the π-conjugated molecules.
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73.61.Ph Polymers; organic compounds
73.50.Dn Low-field transport and mobility; piezoresistance
72.15.Nj Collective modes (e.g., in one-dimensional conductors)
68.55.-a Thin film structure and morphology
85.30.Tv Field effect devices

Schottky barrier modulation on silicon nanowires

J. Piscator and O. Engström

Appl. Phys. Lett. 90, 132107 (2007); http://dx.doi.org/10.1063/1.2717088 (3 pages) | Cited 6 times

Online Publication Date: 27 March 2007

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Oxide charge on the sidewalls of SiO2 embedded silicon wires with 20×20 nm2 cross section is shown to influence the Schottky barrier height for Pd2Si/Si junctions positioned on the end surfaces of the wires. Compared with results on planar silicon surfaces, the electron barrier height is 0.3 eV lower for wires investigated as fabricated. By increasing the oxide charge through irradiation by ultraviolet light, the electron barrier decreases by an additional 0.15 eV and the hole barrier correspondingly increases by about the same amount. The phenomenon is explained by assuming an oxide charge density in the range of 1012 cm−2.
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73.63.-b Electronic transport in nanoscale materials and structures
73.30.+y Surface double layers, Schottky barriers, and work functions
61.80.Ba Ultraviolet, visible, and infrared radiation effects (including laser radiation)
61.82.Fk Semiconductors

Vertically coupled quantum wires in a longitudinal magnetic field

Lev G. Mourokh, Anatoly Yu. Smirnov, and Saskia F. Fischer

Appl. Phys. Lett. 90, 132108 (2007); http://dx.doi.org/10.1063/1.2717147 (3 pages) | Cited 4 times

Online Publication Date: 27 March 2007

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The authors examine analytically the energy subband structure for two vertically stacked quantum wires separated by a tunneling barrier in the presence of a longitudinal magnetic field. For identical harmonic confining potentials, they show that the tunnel splitting between formed symmetric and antisymmetric subbands decreases exponentially with increasing magnetic field and, moreover, the tunnel coupling disappears at appropriate values of the magnetic field in agreement with experimental data. They propose to achieve a controllable coupling of quantum wires with the decoupling magnetic field and with nanomagnets providing coupling windows, which can be used for quantum computation purposes.
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73.63.Nm Quantum wires
73.21.Hb Quantum wires
73.40.Gk Tunneling

Subsurface enrichment of Co in Si (100) at initial stages of growth at room temperature: A study by high-resolution Rutherford backscattering

S. P. Dash, D. Goll, and H. D. Carstanjen

Appl. Phys. Lett. 90, 132109 (2007); http://dx.doi.org/10.1063/1.2717525 (3 pages) | Cited 13 times

Online Publication Date: 27 March 2007

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The Co distribution in the initial stages of growth of Co on Si (100) at room temperature has been probed in situ by high-resolution Rutherford backscattering spectrometry. Even at very low coverage (0.08 ML) extensive Co in-diffusion is found. The in-diffused Co forms a pronounced subsurface maximum which shifts into the Si bulk with increasing coverage and persists up to a coverage of 1.19 ML. The Co concentration at the surface saturates at the value of 0.5 for 1.19 ML of Co. Evidence of Si out-diffusion is seen for 2 and 2.93 ML which results in the formation of a CoSi phase.
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68.35.Fx Diffusion; interface formation
68.49.Sf Ion scattering from surfaces (charge transfer, sputtering, SIMS)

Electrical and Raman characterization of silicon and germanium-filled microstructured optical fibers

C. E. Finlayson, A. Amezcua-Correa, P. J. A. Sazio, N. F. Baril, and J. V. Badding

Appl. Phys. Lett. 90, 132110 (2007); http://dx.doi.org/10.1063/1.2713755 (3 pages) | Cited 17 times

Online Publication Date: 27 March 2007

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Extreme aspect ratio tubes and wires of polycrystalline silicon and germanium have been deposited within silica microstructured optical fibers using high-pressure precursors, demonstrating the potential of a platform technology for the development of in-fiber optoelectronics. Microstructural studies of the deposited material using Raman spectroscopy show effects due to strain between core and cladding and the presence of amorphous and polycrystalline phases for silicon. Germanium, in contrast, is more crystalline and less strained. This in-fiber device geometry is utilized for two- and three-terminal electrical characterization of the key parameters of resistivity and carrier type, mobility and concentration.
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42.81.-i Fiber optics
78.30.Hv Other nonmetallic inorganics
42.82.-m Integrated optics
72.20.Fr Low-field transport and mobility; piezoresistance

Temperature-dependent study of n-ZnO/p-GaN diodes

Kuang-Po Hsueh, Shou-Chien Huang, Ching-Tai Li, Yue-Ming Hsin, Jinn-Kong Sheu, Wei-Chih Lai, and Chun-Ju Tun

Appl. Phys. Lett. 90, 132111 (2007); http://dx.doi.org/10.1063/1.2716324 (3 pages) | Cited 6 times

Online Publication Date: 28 March 2007

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This work investigates the temperature dependence of the current-voltage (I-V) characteristics of n-ZnO/p-GaN junction diodes. The n-ZnO films were deposited on top of the p-GaN by dc sputtering with subsequent annealings at 500, 600, 700, and 800 °C for 60 s. The Hall measurement and the x-ray diffraction pattern are measured to study the n-ZnO films. The temperature sensitivity coefficients of the I-V characterizations are obtained by different substrate temperatures (25, 50, 100, and 150 °C) and the extracted values are 2.10, 1.93, 3.22, and 1.36 mV/°C in the forward bias and 8.7, 8.0, 4.6, and 2.3 mV/°C in the reverse bias, respectively. The fabricated n-ZnO/p-GaN diode with ZnO annealing temperatures at 800 °C demonstrates the lowest temperature dependence.
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85.30.Kk Junction diodes
85.40.Sz Deposition technology

Full-band study of current across silicon nanowire transistors

K. Nehari, N. Cavassilas, F. Michelini, M. Bescond, J. L. Autran, and M. Lannoo

Appl. Phys. Lett. 90, 132112 (2007); http://dx.doi.org/10.1063/1.2716351 (3 pages) | Cited 21 times

Online Publication Date: 28 March 2007

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The authors report an atomistic study of the ballistic current through silicon nanowire metal-oxide-semiconductor transistors. A self-consistent quantum ballistic transport model is used to calculate the current in gate-all-around nanowire transistors, taking into account the full-band structure of the quantum wire with a sp3 tight-binding approach. The authors demonstrate the occurence of an optimal wire cross section for which the on-state/off-state current ratio is maximum, a result which cannot be obtained in a standard bulk effective mass description.
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85.30.Tv Field effect devices

Photoluminescence and built-in electric field in ZnO/Mg0.1Zn0.9O quantum wells

B. P. Zhang, B. L. Liu, J. Z. Yu, Q. M. Wang, C. Y. Liu, Y. C. Liu, and Y. Segawa

Appl. Phys. Lett. 90, 132113 (2007); http://dx.doi.org/10.1063/1.2716367 (3 pages) | Cited 20 times

Online Publication Date: 28 March 2007

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Photoluminescence study of ZnO/Mg0.1Zn0.9O quantum wells with graded well width (Lw) was carried out at 4.2 K. The emission evolution from quantum confinement regime to quantum-confined Stark regime was observed clearly. For large Lw, the emission splits into two peaks which are attributed to the emissions of ZnO band edge and separately localized carriers, respectively. The internal electric field in the well layer was estimated to be ∼ 0.3 MV/cm, being similar to previous reports. The results are useful in designing ZnO QW based optoelectronic devices.
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78.67.De Quantum wells
78.55.Et II-VI semiconductors
73.63.Hs Quantum wells

Regrowth-related defect formation and evolution in 1 MeV amorphized (001) Ge

D. P. Hickey, Z. L. Bryan, K. S. Jones, R. G. Elliman, and E. E. Haller

Appl. Phys. Lett. 90, 132114 (2007); http://dx.doi.org/10.1063/1.2717538 (3 pages) | Cited 6 times

Online Publication Date: 28 March 2007

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Ge implanted with 1 MeV Si+ at a dose of 1×1015 cm−2 creates a buried amorphous layer that, upon regrowth, exhibits several forms of defects–end-of-range (EOR), regrowth-related, and clamshell defects. Unlike Si, no planar {311} defects are observed. The minimal EOR defects are small dotlike defects and are very unstable, dissolving between 450 and 550 °C. This is in contrast to Si, where the EOR defects are very stable. The amorphous layer results in both regrowth-related defects and clamshell defects, which were more stable than the EOR damage.
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61.43.Dq Amorphous semiconductors, metals, and alloys
64.75.-g Phase equilibria
61.80.Jh Ion radiation effects
61.82.Fk Semiconductors

Engineering carrier transport across organic heterojunctions by interface doping

S. W. Tsang, Z. H. Lu, and Y. Tao

Appl. Phys. Lett. 90, 132115 (2007); http://dx.doi.org/10.1063/1.2718273 (3 pages) | Cited 17 times

Online Publication Date: 28 March 2007

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Two common hole transporting materials, 4,4′,4″-tris(N-3-methylphenyl-N-phenyl-amino) triphenylamine (MTDATA) and N,N′-diphenyl-N,N′-bis(1-naphthyl) (1,1′-biphenyl)-4,4′diamine (NPB), and a p-type dopant tetrafluorotetracyanoquinodimethane (F4-TCNQ) were used to build various hole-only heterojunction devices. Both experimental results and theoretical modeling show that the current flow in such devices is limited by the heterojunction potential barrier or band offset at the MTDATA/NPB interface. It was found that the device current flow can be modulated to increase or decrease dramatically by introducing a 2 nm p-doped NPB:F4-TCNQ or MTDATA:F4-TCNQ interlayer, respectively. The observed phenomena were discussed using quasi-Fermi energy level realignment at the doped/undoped organic-organic interface.
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85.30.De Semiconductor-device characterization, design, and modeling
85.40.Ry Impurity doping, diffusion and ion implantation technology

Optical investigations of InN nanodots capped by GaN at different temperatures

C. S. Ku, W. C. Chou, and M. C. Lee

Appl. Phys. Lett. 90, 132116 (2007); http://dx.doi.org/10.1063/1.2716347 (3 pages)

Online Publication Date: 29 March 2007

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InN nanodots capped with GaN for temperatures from 600 to 730 °C were investigated. While the dot emission intensity at 0.77 eV decreased with increasing capping temperature, two extra visible emission bands appeared around 2.37 eV (green band) and 2.96 eV (violet band). Furthermore, x ray diffraction shows that the 71.7° and 70.2° peaks were tentatively attributed to InGaN alloy with In fractions of 14.8% and 34.2%, respectively. Moreover, the near-field measurements helped reveal the regions of different emissions. The violet-band mapping showed a spatial distribution in contrast to nanodot distribution but the green band showed a uniform distribution that apparently reflects the capping induced InGaN alloy.
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78.67.Bf Nanocrystals, nanoparticles, and nanoclusters
78.55.Cr III-V semiconductors
61.46.Hk Nanocrystals

Hydrogen equilibration in polycrystalline silicon

K. von Maydell and N. H. Nickel

Appl. Phys. Lett. 90, 132117 (2007); http://dx.doi.org/10.1063/1.2716348 (3 pages)

Online Publication Date: 29 March 2007

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Hydrogen equilibration in polycrystalline silicon was investigated as a function of annealing time and temperature using electron spin resonance and hydrogen effusion measurements. During a vacuum anneal at least 1.5×1021 cm−3 H atoms are mobile in the lattice, however, only about 3.7×1018 cm−3 H atoms passivate Si dangling bonds. The results show that the annealing treatment can cause the vast majority of H atoms to accumulate in H stabilized platelets. Since defect passivation preferentially occurs at grain boundaries and platelet nucleation and growth are confined to the interior of single-crystal grains, H equilibration is governed by two spatially separated processes. Moreover, the data demonstrate that the hydrogen density-of-states distribution is dynamic and changes in response to experimental parameters.
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81.05.Cy Elemental semiconductors
81.65.Rv Passivation
61.72.S- Impurities in crystals
61.72.Cc Kinetics of defect formation and annealing
71.55.Cn Elemental semiconductors
76.30.-v Electron paramagnetic resonance and relaxation

Deposition of In2S3 on Cu(In,Ga)(S,Se)2 thin film solar cell absorbers by spray ion layer gas reaction: Evidence of strong interfacial diffusion

M. Bär, N. Allsop, I. Lauermann, and Ch.-H. Fischer

Appl. Phys. Lett. 90, 132118 (2007); http://dx.doi.org/10.1063/1.2717534 (3 pages) | Cited 8 times

Online Publication Date: 29 March 2007

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Recently, Cd-free Cu(In,Ga)(S,Se)2-based “CIGSSe” thin film solar cells with a nominal In2S3 buffer layer deposited by the spray ion layer gas reaction technique resulted in photovoltaic performances comparable to that of CdS buffered references. In the past it was argued that diffusion processes across the In2S3/CIGSSe interface play a significant role for the device quality. Investigating the interface formation by using x-ray photoelectron spectroscopy, the authors were able to confirm a strong interfacial diffusion involving Cu and Na from the CIGSSe.
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81.15.Rs Spray coating techniques
68.55.A- Nucleation and growth
84.60.Jt Photoelectric conversion
66.30.Ny Chemical interdiffusion; diffusion barriers
79.60.Jv Interfaces; heterostructures; nanostructures
73.61.Le Other inorganic semiconductors

Current-induced magnetoresistance oscillations in two-dimensional electron systems

X. L. Lei

Appl. Phys. Lett. 90, 132119 (2007); http://dx.doi.org/10.1063/1.2717572 (3 pages) | Cited 26 times

Online Publication Date: 29 March 2007

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Electric current-induced magnetoresistance oscillations recently discovered in two-dimensional electron systems are analyzed using a microscopic scheme for nonlinear magnetotransport direct controlled by the current. The magnetoresistance oscillations are shown to result from drift-motion assisted electron scatterings between Landau levels. The theoretical predictions not only reproduce all the main features observed in the experiments but also disclose other details of the phenomenon.
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73.63.-b Electronic transport in nanoscale materials and structures
72.20.My Galvanomagnetic and other magnetotransport effects

Amorphous Si/Au wafer bonding

P. H. Chen, C. L. Lin, and C. Y. Liu

Appl. Phys. Lett. 90, 132120 (2007); http://dx.doi.org/10.1063/1.2719025 (3 pages) | Cited 9 times

Online Publication Date: 30 March 2007

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The authors report a rapid reaction between Au and amorphous Si (a-Si), which occurred at a much faster rate compared to the case of crystal Si/Au reaction. With an amorphous Si coating layer on crystal Si (c-Si) wafer, air voids and craters were prevented from forming at the Si/Au bonding interface, but were usually found at the crystal Si/Au bonding interface. The uniform liquid eutectic Au–Si alloy quickly formed at the Au/amorphous Si bonding interface is the key for the prevention of air voids and craters. This amorphous Si/Au bonding process enables the feasibility of eutectic Au/Si bonding for wafer bonding applications.
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85.40.-e Microelectronics: LSI, VLSI, ULSI; integrated circuit fabrication technology
85.30.-z Semiconductor devices

Thickness-dependent energy level alignment of rubrene adsorbed on Au(111)

Li Wang, Shi Chen, Lei Liu, Dongchen Qi, Xingyu Gao, and Andrew T. S. Wee

Appl. Phys. Lett. 90, 132121 (2007); http://dx.doi.org/10.1063/1.2719033 (3 pages) | Cited 9 times

Online Publication Date: 30 March 2007

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Energy level alignment of rubrene adsorbed on Au(111) was studied by photoemission spectroscopy. After rubrene adsorption, the work function is reduced from 5.24 eV for clean Au to 4.31 eV, suggesting the invalidity of vacuum level alignment and the presence of a strong interfacial dipole. The frontier molecular orbital energies of rubrene are modified by electrode surface polarization in the submonolayer regime. As a consequence, the hole injection barrier is thickness dependent and varies from about 0.4 eV for a monolayer of rubrene to 0.9 eV for a thick layer.
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73.30.+y Surface double layers, Schottky barriers, and work functions
68.43.Mn Adsorption kinetics
79.60.Bm Clean metal, semiconductor, and insulator surfaces

Graphene-based resonant-tunneling structures

J. Milton Pereira, Jr., P. Vasilopoulos, and F. M. Peeters

Appl. Phys. Lett. 90, 132122 (2007); http://dx.doi.org/10.1063/1.2717092 (3 pages) | Cited 77 times

Online Publication Date: 30 March 2007

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Resonant electronic transmission through graphene-based double barriers (wells) is studied as a function of the incident wave vector, the widths and heights (depths) of the barriers (wells), and the separation between them. Resonant features in the transmission result from resonant electron states in the wells or hole states in the barriers and strongly influence the ballistic conductance of the structures.
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73.21.Fg Quantum wells
73.23.Ad Ballistic transport

Band diagrams of spin tunneling junctions La0.6Sr0.4MnO3/Nb:SrTiO3 and SrRuO3/Nb:SrTiO3 determined by in situ photoemission spectroscopy

M. Minohara, I. Ohkubo, H. Kumigashira, and M. Oshima

Appl. Phys. Lett. 90, 132123 (2007); http://dx.doi.org/10.1063/1.2717517 (3 pages) | Cited 18 times

Online Publication Date: 30 March 2007

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The authors report on the band diagram for epitaxial Schottky junctions of ferromagnetic metallic oxides [half-metallic ferromagnet La0.6Sr0.4MnO3 (LSMO) and itinerant ferromagnet SrRuO3 (SRO)] on Nb-doped SrTiO3 (Nb:STO) semiconductor substrates using in situ photoemission spectroscopy. The ideal Schottky barrier is formed in SRO/Nb:STO junctions with Schottky barrier height (SBH) of 1.2±0.1 eV, while the measured SBH of LSMO/Nb:STO (1.2±0.1 eV) is much larger than the prediction from the Schottky-Mott rule (0.7±0.1 eV). These results suggest that a certain interface dipole is formed at the LSMO/Nb:STO interface.
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73.20.At Surface states, band structure, electron density of states
73.30.+y Surface double layers, Schottky barriers, and work functions
75.70.Cn Magnetic properties of interfaces (multilayers, superlattices, heterostructures)
79.60.Jv Interfaces; heterostructures; nanostructures
75.10.Lp Band and itinerant models
75.50.Dd Nonmetallic ferromagnetic materials

Surface-induced large side-gating phenomenon in GaAs quantum wire transistors and its removal by surface passivation using Si interface control layer

Rui Jia, Seiya Kasai, Qing Wang, Shi Bing Long, Jie Bin Niu, Zhi Gang Li, and Ming Liu

Appl. Phys. Lett. 90, 132124 (2007); http://dx.doi.org/10.1063/1.2718275 (3 pages)

Online Publication Date: 30 March 2007

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Side-gating behaviors of GaAs-based quantum wire transistors (QWRTr’s) were investigated. Using AlGaAs/GaAs high electron mobility transistor wafer, the QWRTr was fabricated with a nanosized side gate beside the nanowire. Anomalous large side-gating effect was found for the QWRTr. Experiments showed that the large side-gating effect was owing to the strong surface Fermi level pinning around the nanowire, which is caused by a thin layer of deep traps located at the surface. Then, Si interface control layer passivation technology was performed to remove the large side gating.
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85.30.Tv Field effect devices
85.30.De Semiconductor-device characterization, design, and modeling
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