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

3 Oct 2011

Volume 99, Issue 14, Articles (14xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 99, 141901 (2011); http://dx.doi.org/10.1063/1.3644948 (3 pages)

G. Kozlowski, P. Zaumseil, M. A. Schubert, Y. Yamamoto, J. Bauer, J. Matejova, T. Schulli, B. Tillack, and T. Schroeder
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Insight into unusual impurity absorbability of GeO2 in GeO2/Ge stacks

Shingo Ogawa, Taichi Suda, Takashi Yamamoto, Katsuhiro Kutsuki, Iori Hideshima, Takuji Hosoi, Takayoshi Shimura, and Heiji Watanabe

Appl. Phys. Lett. 99, 142101 (2011); http://dx.doi.org/10.1063/1.3644393 (3 pages) | Cited 3 times

Online Publication Date: 3 October 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Adsorbed species and its diffusion behaviors in GeO2/Ge stacks, which are future alternative metal-oxide-semiconductor (MOS) materials, have been investigated using various physical analyses. We clarified that GeO2 rapidly absorbs moisture in air just after its exposure. After the absorbed moisture in GeO2 reaches a certain limit, the GeO2 starts to absorb some organic molecules, which is accompanied by a structural change in GeO2 to form a partial carbonate or hydroxide. We also found that the hydrogen distribution in GeO2 shows intrinsic characteristics, indicative of different diffusion behaviors at the surface and at the GeO2/Ge interface. Because the impurity absorbability of GeO2 has a great influence on the electrical properties in Ge-MOS devices, these results provide valuable information in realizing high quality GeO2/Ge stacks for the actual use of Ge-MOS technologies.
Show PACS
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
68.43.Jk Diffusion of adsorbates, kinetics of coarsening and aggregation
68.43.Mn Adsorption kinetics

Soft x-ray emission spectroscopy studies of the electronic structure of silicon supersaturated with sulfur

J. T. Sullivan, R. G. Wilks, M. T. Winkler, L. Weinhardt, D. Recht, A. J. Said, B. K. Newman, Y. Zhang, M. Blum, S. Krause, W. L. Yang, C. Heske, M. J. Aziz, M. Bär, and T. Buonassisi

Appl. Phys. Lett. 99, 142102 (2011); http://dx.doi.org/10.1063/1.3643050 (3 pages) | Cited 2 times

Online Publication Date: 3 October 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We apply soft x-ray emission spectroscopy (XES) to measure the electronic structure of crystalline silicon supersaturated with sulfur (up to 0.7 at. %), a candidate intermediate-band solar cell material. Si L2,3 emission features are observed above the conventional Si valence band maximum, with intensity scaling linearly with S concentration. The lineshape of the S-induced features change across the insulator-to-metal transition, indicating a significant modification of the local electronic structure concurrent with the change in macroscopic electronic behavior. The relationship between the Si L2,3 XES spectral features and the anomalously high sub-band gap infrared absorption is discussed.
Show PACS
78.70.En X-ray emission spectra and fluorescence
78.30.Am Elemental semiconductors and insulators
71.20.Mq Elemental semiconductors

Origin of the electrical instabilities in GaN/AlGaN double-barrier structure

S. Sakr, E. Warde, M. Tchernycheva, L. Rigutti, N. Isac, and F. H. Julien

Appl. Phys. Lett. 99, 142103 (2011); http://dx.doi.org/10.1063/1.3645011 (3 pages) | Cited 6 times

Online Publication Date: 3 October 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The effect of the temperature on the electrical characteristics in GaN-based resonant tunneling diodes is studied both theoretically and experimentally. At room temperature, the current-voltage measurements show reproducible negative differential resistances and a current hysteresis. However these features disappear when the temperature is decreased down to 100 K. In addition, the current exhibits transients over a few tenths of seconds which effect disappears at low temperatures. Based on these results, we conclude that the observed negative differential resistance at room temperature is not due to electron resonant tunneling but to trap charging and release.
Show PACS
85.30.Mn Junction breakdown and tunneling devices (including resonance tunneling devices)
85.30.Kk Junction diodes

Molecular orbital ordering in titania and the associated semiconducting behavior

Joseph Park, Kyung-Chul Ok, Byung Du Ahn, Je Hun Lee, Jae-Woo Park, Kwun-Bum Chung, and Jin-Seong Park

Appl. Phys. Lett. 99, 142104 (2011); http://dx.doi.org/10.1063/1.3646105 (3 pages) | Cited 5 times

Online Publication Date: 3 October 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
RF-sputtered TiOx layers were thermally treated and the associated thin-film transistor properties were studied. X-ray diffraction and x-ray absorption spectroscopy analyses indicate that as-grown amorphous TiOx films crystallize to anatase at temperatures above 450 °C in air. Thin-film transistors incorporating anatase active layers exhibit n-type behavior, with field effect mobility values near 0.11 cm2/Vs when annealed at 550 °C. Such a phenomenon is suggested to originate from the ordering of Ti 3d orbitals upon crystallization, and the mobility enhancement at higher annealing temperatures may be attributed to the reduced grain boundary scattering of carriers by virtue of enlarged average grain size.
Show PACS
68.55.ag Semiconductors
78.70.Dm X-ray absorption spectra
81.40.Ef Cold working, work hardening; annealing, post-deformation annealing, quenching, tempering recovery, and crystallization
61.72.Mm Grain and twin boundaries
81.15.Cd Deposition by sputtering
85.30.Tv Field effect devices

Behavior of nitrogen atoms in SiC-SiO2 interfaces studied by electrically detected magnetic resonance

T. Umeda, K. Esaki, R. Kosugi, K. Fukuda, T. Ohshima, N. Morishita, and J. Isoya

Appl. Phys. Lett. 99, 142105 (2011); http://dx.doi.org/10.1063/1.3644156 (3 pages) | Cited 4 times

Online Publication Date: 4 October 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The microscopic behavior of nitrogen atoms in the SiO2-SiC interface regions of n-channel lateral 4 H-SiC metal-oxide-semiconductor field effect transistors (MOSFETs) was studied using low-temperature electrically detected magnetic resonance spectroscopy and other techniques. The results show that nitrogen atoms eliminated shallow interface states observable at 20 K and further diffused into the channel region of the MOSFETs as shallow donors. These two behaviors enable nitrogen atoms to change the channel conductivity of SiC MOSFETs.
Show PACS
73.20.At Surface states, band structure, electron density of states
85.30.Tv Field effect devices

Long hold times in a two-junction electron trap

A. Kemppinen, S. V. Lotkhov, O.-P. Saira, A. B. Zorin, J. P. Pekola, and A. J. Manninen

Appl. Phys. Lett. 99, 142106 (2011); http://dx.doi.org/10.1063/1.3647557 (3 pages) | Cited 3 times

Online Publication Date: 5 October 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The hold time τ of a single-electron trap is shown to increase significantly due to suppression of photon assisted tunneling events. Using two rf-tight radiation shields instead of a single one, we demonstrate increase of τ by a factor exceeding 103, up to about 10 h, for a trap with only two superconductor (S)—normal-metal (N) tunnel junctions and an on-chip resistor R ∼ 100 kΩ (R-SNS structure). In the normal state, the improved shielding made it possible to observe τ ∼ 100 s, which is in reasonable agreement with the quantum-leakage-limited level expected for the two-electron cotunneling process.
Show PACS
85.25.Cp Josephson devices
74.45.+c Proximity effects; Andreev reflection; SN and SNS junctions
74.55.+v Tunneling phenomena: single particle tunneling and STM
84.32.Ff Conductors, resistors (including thermistors, varistors, and photoresistors)

Effect of temperature on CO detection sensitivity of ZnO nanorod-gated AlGaN/GaN high electron mobility transistors

Chien-Fong Lo, B. H. Chu, S. J. Pearton, A. Dabiran, P. P. Chow, S. Doré, S. C. Hung, C. W. Chen, and F. Ren

Appl. Phys. Lett. 99, 142107 (2011); http://dx.doi.org/10.1063/1.3647561 (3 pages) | Cited 1 time

Online Publication Date: 5 October 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The carbon monoxide (CO) detection sensitivities of ZnO nanorod-gated AlGaN/GaN high electron mobility transistors were measured over a range of temperatures from 25–150 °C. Once the sensor was exposed to the CO-containing ambient, the drain current, I, of the high electron mobility transistors increased due to chemisorbed oxygen on the ZnO surface reacting with CO, forming CO2 and releasing electrons to the oxide surface. Although the sensor could detect CO as low as 100 ppm at room temperature, the detection sensitivity, ΔI/I, was only around 0.23%. By increasing the sensor temperature to 150 °C, the detection sensitivity was improved by a factor of over 30% to 7.5%.
Show PACS
07.07.Df Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing
82.80.-d Chemical analysis and related physical methods of analysis
85.30.Tv Field effect devices

Highly strained-SiGe-on-insulator p-channel metal-oxide-semiconductor field-effective transistors fabricated by applying Ge condensation technique to strained-Si-on-insulator substrates

Junkyo Suh, Ryosho Nakane, Noriyuki Taoka, Mitsuru Takenaka, and Shinichi Takagi

Appl. Phys. Lett. 99, 142108 (2011); http://dx.doi.org/10.1063/1.3647631 (3 pages) | Cited 3 times

Online Publication Date: 5 October 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
High hole mobility enhancement of strained SiGe-on-insulator (sSGOI) p-channel metal-oxide-semiconductor field-effect transistors (pMOSFETs) has been achieved by utilizing strained-SOI (sSOI) substrates in Ge condensation. The initial tensile strain in the sSOI substrates alleviates strain relaxation during Ge condensation process, because of smaller lattice mismatch to Ge than conventional unstrained SOI substrates. In addition, generation of hole carrier concentration and degradation of bottom interface are suppressed. Mitigation in strain relaxation is shown to effectively increase strain in SGOI layers and resulting hole mobility in the SGOI pMOSFETs in high Ge content region. The observed high mobility enhancement can be quantitatively explained by the combination of high Ge content and a large amount of compressive strain, through comparison of experimental data with theoretical calculations.
Show PACS
85.30.Tv Field effect devices

Prediction of the chemical trends of oxygen vacancy levels in binary metal oxides

Wan-Jian Yin, Su-Huai Wei, Mowafak M. Al-Jassim, and Yanfa Yan

Appl. Phys. Lett. 99, 142109 (2011); http://dx.doi.org/10.1063/1.3647756 (3 pages) | Cited 2 times

Online Publication Date: 5 October 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We propose simple principles to predict qualitatively the chemical trends of oxygen vacancy levels in binary metal oxides by analyzing the atomic wavefunction characters of the conduction-band minimum (CBM). We show that if the CBM is a metal-oxygen antibonding state due to either s-s coupling, p-p coupling, or p-d coupling, then, in general, the oxygen vacancy level is deep. The stronger coupling leads to deeper levels. If the CBM is a non-bonding d state, then the oxygen vacancy level could be shallow. These principles are confirmed by the calculated trends of oxygen vacancy levels in representative binary metal oxides using hybrid density-functional method.
Show PACS
61.72.jd Vacancies
71.15.Mb Density functional theory, local density approximation, gradient and other corrections
71.55.Ht Other nonmetals

Flexible resistive random access memory using solution-processed TiOx with Al top electrode on Ag layer-inserted indium-zinc-tin-oxide-coated polyethersulfone substrate

Seungjae Jung, Jaemin Kong, Sunghoon Song, Kwanghee Lee, Takhee Lee, Hyunsang Hwang, and Sanghun Jeon

Appl. Phys. Lett. 99, 142110 (2011); http://dx.doi.org/10.1063/1.3621826 (3 pages) | Cited 2 times

Online Publication Date: 5 October 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We demonstrated a flexible resistive random access memory (FReRAM) device using a solution-processed TiOx active layer with an Al top electrode on an Ag layer-inserted indium-zinc-tin-oxide (IAI)-coated polyethersulfone substrate (Al/TiOx/IAI). Its feasibility of FReRAM application was evaluated through the comparison of electrical and mechanical characteristics with devices having different structure such as Ag/TiOx/Ag, Al/TiOx/indium-tin-oxide, and Al/TiOx/Al. As a result, our FReRAM device exhibited greater FReRAM performance such as stable memory characteristics under mechanically bent conditions and robustness to repetitive bending cycles. In addition, the device was thermally stable up to 85 °C, despite its flexible electrode and polymer substrate.
Show PACS
84.30.Sk Pulse and digital circuits

Oxygen-enhanced wet thermal oxidation of GaAs

J. F. Bauters, R. E. Fenlon, C. S. Seibert, W. Yuan, J. S. B. Plunkett, J. Li, and D. C. Hall

Appl. Phys. Lett. 99, 142111 (2011); http://dx.doi.org/10.1063/1.3647579 (3 pages) | Cited 1 time

Online Publication Date: 6 October 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
An oxygen-enhanced wet thermal oxidation process is used to grow smooth, uniform, insulating native oxides of GaAs. At 420 °C, a maximum linear growth rate of 4.8 nm/min is observed for oxidation in water vapor with 2000 ppm O2 added relative to the N2 carrier gas, with growth ceasing by 7000 ppm. Films as thick as 800 nm with surface roughness as low as 0.2 nm are demonstrated. In fabricated metal-oxide-semiconductor capacitors, a 412 nm thick native oxide film exhibits a factor of ∼2700 reduction in leakage current density at 1 V relative to a direct metal (Au:Ti) to GaAs contact.
Show PACS
81.65.Mq Oxidation
84.32.Tt Capacitors
85.30.Tv Field effect devices
68.35.bg Semiconductors
68.55.ag Semiconductors
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy

Experimental observation of an enhanced anisotropic magnetoresistance in non-local configuration

D. Rüffer, F. D. Czeschka, R. Gross, and S. T. B. Goennenwein

Appl. Phys. Lett. 99, 142112 (2011); http://dx.doi.org/10.1063/1.3640487 (3 pages)

Online Publication Date: 6 October 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We compare non-local magnetoresistance measurements in multi-terminal Ni nanostructures with corresponding local experiments. In both configurations, the measured voltages show the characteristic features of anisotropic magnetoresistance (AMR). However, the magnitude of the non-local AMR signal is up to one order of magnitude larger than its local counterpart. Moreover, the non-local AMR increases with increasing degree of non-locality, i.e., with the separation between the region of the main current flow and the voltage measurement region. All experimental observations can be consistently modeled in terms of current spreading in a non-isotropic conductor. Our results show that current spreading can significantly enhance the magnetoresistance signal in non-local experiments.
Show PACS
75.75.-c Magnetic properties of nanostructures
75.47.Np Metals and alloys
75.50.Cc Other ferromagnetic metals and alloys
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close