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

17 Nov 2008

Volume 93, Issue 20, Articles (20xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 93, 201101 (2008); http://dx.doi.org/10.1063/1.3025818 (3 pages)

W. Dai and C. M. Soukoulis
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Reorientation of (MnTi″−VO••)× defect dipoles in acceptor-modified BaTiO3 single crystals: An electron paramagnetic resonance study

Lixue Zhang, Emre Erdem, Xiaobing Ren, and Rüdiger-A. Eichel

Appl. Phys. Lett. 93, 202901 (2008); http://dx.doi.org/10.1063/1.3006327 (3 pages) | Cited 24 times

Online Publication Date: 18 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The effect of external electric fields on the orientation of (MnTi″−VO••)× defect dipoles in ferroelectric BaTiO3 single crystals and its interplay with the domain structure were investigated by means of electron paramagnetic resonance (EPR) spectroscopy and optical microscopy. The results show that in specimens aged in the ferroelectric state for a defined time, so-termed ferroelectrically aged, the (MnTi″−VO••)× defect dipoles orient along the direction of spontaneous polarization and follow the domain switching upon poling with correspondingly high electric fields. A comparison of the EPR signal in poled aged single-domain samples to that in naturally aged multidomain samples indicates a similar reorientation process of the defect dipole, which means that dipole reorientation rather requires long time, thermal energy, and high electric fields, i.e., more energy.
Show PACS
77.80.Dj Domain structure; hysteresis
76.30.Mi Color centers and other defects
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
61.72.jd Vacancies
77.80.Fm Switching phenomena
77.22.Ej Polarization and depolarization

Half-cycle atomic layer deposition reaction studies of Al2O3 on In0.2Ga0.8As (100) surfaces

M. Milojevic, F. S. Aguirre-Tostado, C. L. Hinkle, H. C. Kim, E. M. Vogel, J. Kim, and R. M. Wallace

Appl. Phys. Lett. 93, 202902 (2008); http://dx.doi.org/10.1063/1.3033404 (3 pages) | Cited 56 times

Online Publication Date: 19 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The reduction in III–V interfacial oxides by atomic layer deposition of Al2O3 on InGaAs is studied by interrupting the deposition following individual trimethyl aluminum (TMA) and water steps (half cycles) and interrogation of the resultant surface reactions using in situ monochromatic x-ray photoelectron spectroscopy (XPS). TMA is found to reduce the interfacial oxides during the initial exposure. Concentrations of Ga oxide on the surface processed at 300 °C are reduced to a concentration on the order of a monolayer, while AsOx species are below the level of detection of XPS.
Show PACS
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces
79.60.Bm Clean metal, semiconductor, and insulator surfaces
68.55.aj Insulators
82.30.-b Specific chemical reactions; reaction mechanisms

Achieving a low interfacial density of states in atomic layer deposited Al2O3 on In0.53Ga0.47As

H. C. Chiu, L. T. Tung, Y. H. Chang, Y. J. Lee, C. C. Chang, J. Kwo, and M. Hong

Appl. Phys. Lett. 93, 202903 (2008); http://dx.doi.org/10.1063/1.3027476 (3 pages) | Cited 23 times

Online Publication Date: 19 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Atomic-layer-deposited Al2O3 on In0.53Ga0.47As with short air exposure between the oxide and semiconductor deposition has enabled the demonstration of nearly ideal frequency-dependent and quasistatic capacitance-voltage (C-V) characteristics. The excellent quasistatic C-V characteristics indicate a high efficiency of 63% for the Fermi-level movement near the midgap. A low mean interfacial density of states (mathit) ∼ 2.5×1011 cm−2 eV−1 was determined under 1 MHz using a charge pumping method, which was also employed to probe the depth profile of bulk traps (Nbt) and the energy dependence of Dit at 50 kHz: a low Nbt ∼ 7×1018 cm−3 and a Dit of (2–4)×1011 cm−2 eV−1 in the lower half of the band gap and a higher Dit of ∼ 1012 cm−2 eV−1 in the upper half of the band gap. The employment of charge pumping method has given a more accurate determination of Dit, which is usually overestimated using other commonly methods such as the Terman, conductance, and high-low frequencies due to the influence of weak inversion at room temperature.
Show PACS
73.20.At Surface states, band structure, electron density of states
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)

Interface control and leakage current conduction mechanism in HfO2 film prepared by pulsed laser deposition

Hao Wang, Y. Wang, J. Zhang, C. Ye, H. B. Wang, J. Feng, B. Y. Wang, Q. Li, and Y. Jiang

Appl. Phys. Lett. 93, 202904 (2008); http://dx.doi.org/10.1063/1.3033526 (3 pages) | Cited 20 times

Online Publication Date: 20 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The N2 atmosphere postannealing is introduced to improve the interfacial quality and the dielectric properties of HfO2 films prepared by pulsed laser deposition. The disappearance of interface layer between HfO2 film and Si substrate and the decrease of leakage current densities after annealing are further confirmed by high-resolution cross-sectional transmission electron microscopy investigation and electrical measurement. Electric conduction analysis results show that the dominant leakage current conduction mechanisms of the annealed HfO2 film are the Schottky emission at low electric field, the trap-assisted tunneling, and space-charge-limited current at high electric field for the gate and substrate injections, respectively.
Show PACS
77.55.-g Dielectric thin films
81.15.Fg Pulsed laser ablation deposition
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
68.37.-d Microscopy of surfaces, interfaces, and thin films

Pseudoferroelectricity: A possible scenario for doped ZnO

Alexander K. Tagantsev

Appl. Phys. Lett. 93, 202905 (2008); http://dx.doi.org/10.1063/1.3036537 (3 pages) | Cited 5 times

Online Publication Date: 21 November 2008

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A phenomenological Landau-theory model, where a crystal on cooling from a state with polar symmetry exhibits a maximum of dielectric permittivity and polarization-field hysteresis loops, is offered. The model is equivalent to that of a true ferroelectric in a weak external dc bias. Permittivity maximum occurs as a result of crossing the Widom line. In the model, the role of the external bias plays an intrinsic internal bias originating from a weak polarity of the high temperature state of the material. The results obtained show that the ferroelectriclike phenomena reported for doped ZnO are compatible with a Landau-theory description.
Show PACS
77.80.Dj Domain structure; hysteresis
77.22.Ch Permittivity (dielectric function)
77.84.Bw Elements, oxides, nitrides, borides, carbides, chalcogenides, etc.
61.72.uj III-V and II-VI semiconductors
71.70.Di Landau levels
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close