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

6 Sep 2004

Volume 85, Issue 10, pp. 1659-1861

Issue Cover Spotlight Figure

Appl. Phys. Lett. 85, 1793 (2004); http://dx.doi.org/10.1063/1.1790588 (3 pages)

Hyunsik Yoon, Kyoung Mi Lee, Dahl-Young Khang, Hong H. Lee, and Se-Jin Choi
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

n-type conductivity in ultrananocrystalline diamond films

Oliver A. Williams, Stephane Curat, Jennifer E. Gerbi, Dieter M. Gruen, and Richard B. Jackman

Appl. Phys. Lett. 85, 1680 (2004); http://dx.doi.org/10.1063/1.1785288 (3 pages) | Cited 66 times

Full Text: Read Online (HTML) | Download PDF


See Also: Publisher's Note

Show Abstract
Hall effect measurements have been carried out to determine the carrier density and mobilities in ultrananocrystalline diamond films grown with added nitrogen. The results show clear n-type conductivity with very low thermal activation energy. Mobility values of 1.5 cm2 V−1 s−1 are found for a sheet carrier concentration of 2×1017 cm−2. These measurements indicate that ultrananocrystalline films grown with high nitrogen levels in the growth gas mixture can have bulk carrier concentrations of up to 1021, which is very high for diamond films. The n-type nature of this material was also confirmed by Seebeck effect measurements.
Show PACS
72.20.My Galvanomagnetic and other magnetotransport effects
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
73.61.Cw Elemental semiconductors
73.50.Lw Thermoelectric effects
81.07.Bc Nanocrystalline materials
81.05.Cy Elemental semiconductors
71.55.Cn Elemental semiconductors
68.55.A- Nucleation and growth
72.20.Pa Thermoelectric and thermomagnetic effects
61.72.S- Impurities in crystals
61.72.up Other materials
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.

Transmission electron microscopy study of blisters in high-temperature annealed He and H co-implanted single-crystal silicon

S. Frabboni, G. C. Gazzadi, L. Felisari, R. Tonini, F. Corni, and G. Ottaviani

Appl. Phys. Lett. 85, 1683 (2004); http://dx.doi.org/10.1063/1.1790031 (3 pages) | Cited 4 times

Online Publication Date: 13 September 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Transmission electron microscopy has allowed us to draw the three-dimensional structure of blisters formed after high-temperature annealing of He-H co-implanted silicon by combining the unique capability of site-selective cross sectioning of the focused ion beam with conventional plan view images. It has been shown that blisters are formed by crystalline lamellae strongly bended, plastically deformed, and suspended over buried empty cavities. The volume of the protruding blister surface is almost equal to the buried empty volumes, thus suggesting a mechanism for blister formation based on H and He precipitation and migration of silicon atoms toward the surface.
Show PACS
68.47.Fg Semiconductor surfaces
68.37.Lp Transmission electron microscopy (TEM)
68.35.B- Structure of clean surfaces (and surface reconstruction)
61.72.Cc Kinetics of defect formation and annealing
64.75.-g Phase equilibria
61.72.uf Ge and Si
61.66.Bi Elemental solids

Influence of overlayer thickness on the density of Lomer dislocations in nanoscale Ni–Cu bilayer thin films

D. Mitlin, A. Misra, T. E. Mitchell, R. G. Hoagland, and J. P. Hirth

Appl. Phys. Lett. 85, 1686 (2004); http://dx.doi.org/10.1063/1.1779343 (3 pages) | Cited 5 times

Online Publication Date: 13 September 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on the evolution of the spacing and the character of misfit dislocations with increasing Ni overlayer thickness at an (001) Ni–Cu interface. At low Ni overlayer thicknesses (3 and 5 nm), most of the interface dislocations are 60° 1∕2〈110〉 glide dislocations, while Lomer edge dislocations constitute only about 5% of the total interface dislocation content. At a 13 nm Ni overlayer thickness, the fraction of Lomer dislocations increases to approximately 40% of the total content. This dramatic increase in the fraction of Lomer dislocations is likely related to a “rebound mechanism” which initiates at some critical thickness between 5 and 13 nm.
Show PACS
61.72.Hh Indirect evidence of dislocations and other defects (resistivity, slip, creep, strains, internal friction, EPR, NMR, etc.)
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.

Near-infrared electroluminescence at room temperature from neodymium-doped gallium nitride thin films

Joo Han Kim and Paul H. Holloway

Appl. Phys. Lett. 85, 1689 (2004); http://dx.doi.org/10.1063/1.1781745 (3 pages) | Cited 13 times

Online Publication Date: 13 September 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Strong near-infrared (NIR) electroluminescence (EL) at room temperature from neodymium (Nd)-doped gallium nitride (GaN) thin films is reported. The Nd-doped GaN films were grown by radio-frequency planar magnetron cosputtering of separate GaN and metallic Nd targets in a pure nitrogen ambient. X-ray diffraction data did not identify the presence of any secondary phases and revealed that the Nd-doped GaN films had a highly textured wurtzite crystal structure with the c-axis normal to the surface of the film. The EL devices were fabricated with a thin-film multilayered structure of Al∕Nd-doped GaN∕Al2O3–TiO2∕indium-tin oxide and tested at room temperate. Three distinct NIR EL emission peaks were observed from the devices at 905, 1082, and 1364 nm, arising from the radiative relaxation of the 4F3∕2 excited-state energy level to the 4I9∕2, 4I11∕2, and 4I13∕2 levels of the Nd3+ ion, respectively. The threshold voltage for all the three emission peaks was ∼150 V. The external power efficiency of the fabricated EL devices was ∼1×10−5 measured at 40 V above the threshold voltage.
Show PACS
85.60.Jb Light-emitting devices
81.05.Ea III-V semiconductors
78.66.Fd III-V semiconductors
78.60.Fi Electroluminescence
68.55.-a Thin film structure and morphology
81.15.Cd Deposition by sputtering
81.40.Ef Cold working, work hardening; annealing, post-deformation annealing, quenching, tempering recovery, and crystallization
68.65.Ac Multilayers
73.21.Ac Multilayers
78.67.Pt Multilayers; superlattices; photonic structures; metamaterials

Mechanisms of nitrogen incorporation in GaAsN alloys

M. Reason, H. A. McKay, W. Ye, S. Hanson, R. S. Goldman, and V. Rotberg

Appl. Phys. Lett. 85, 1692 (2004); http://dx.doi.org/10.1063/1.1789237 (3 pages) | Cited 23 times

Online Publication Date: 13 September 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have investigated nitrogen incorporation mechanisms in dilute nitride GaAsN alloys grown by plasma-assisted molecular-beam epitaxy. A comparison of nuclear reaction analysis and Rutherford backscattering spectrometry in channeling and nonchanneling conditions reveals significant composition-dependent incorporation of N into nonsubstitutional sites, presumably as either N–N or N–As split interstitials. Furthermore, we identify the (2×1) reconstruction as the surface structure which leads to the highest substitutional N incorporation, likely due to the high number of group V sites per unit area available for N–As surface exchange.
Show PACS
81.05.Ea III-V semiconductors
68.47.Fg Semiconductor surfaces
61.85.+p Channeling phenomena (blocking, energy loss, etc.)
68.55.-a Thin film structure and morphology
68.35.B- Structure of clean surfaces (and surface reconstruction)
61.72.J- Point defects and defect clusters
61.72.S- Impurities in crystals
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
52.77.Dq Plasma-based ion implantation and deposition

Nanoindentation of polycrystalline silicon-carbide thin films studied by acoustic emission

X.-G. Ma, K. Komvopoulos, and D. B. Bogy

Appl. Phys. Lett. 85, 1695 (2004); http://dx.doi.org/10.1063/1.1784880 (3 pages) | Cited 1 time

Online Publication Date: 13 September 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Nanoindentation experiments and in situ monitoring of acoustic emission (AE) were used to investigate the evolution of deformation in polycrystalline silicon-carbide thin films. An acoustic sensor attached to the holder of the indenter tip was used to continuously record the AE signal during nanoindentation. The amplitudes of the AE wave forms were used to analyze the response of the indented films in the time domain. In addition, a hybrid time-frequency analysis of the AE events was performed in order to determine the dominant frequencies of the deformation events encountered during nanoindentation. The effects of the film thickness and microstructure and the indenter tip radius on the film deformation behavior are interpreted in terms of the AE response and associated deformation mechanisms. The findings of this study demonstrate that in situ AE monitoring provides potentially useful information about microstructure changes associated with nanoscale deformation processes, such as grain boundary cracking, in thin films subjected to normal contact loading.
Show PACS
68.60.Bs Mechanical and acoustical properties
81.40.Lm Deformation, plasticity, and creep
62.20.F- Deformation and plasticity
81.40.Np Fatigue, corrosion fatigue, embrittlement, cracking, fracture, and failure
62.20.M- Structural failure of materials
61.72.Mm Grain and twin boundaries
62.20.Qp Friction, tribology, and hardness
81.70.Cv Nondestructive testing: ultrasonic testing, photoacoustic testing

Cobalt valence in epitaxial Ti0.93Co0.07O2 anatase

M. L. Cui, J. Zhu, X. Y. Zhong, Y. G. Zhao, and X. F. Duan

Appl. Phys. Lett. 85, 1698 (2004); http://dx.doi.org/10.1063/1.1784885 (3 pages) | Cited 16 times

Online Publication Date: 13 September 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Anatase Ti0.93Co0.07O2 films, synthesized by pulsed-laser deposition, have been investigated in the transmission electron microscope using selected area electron diffraction, energy dispersive x-ray analysis, and electron-energy-loss spectroscopy (EELS), and by x-ray diffraction measurements. It is found that Co ions are soluble in anatase, and that the unit-cell c-axis parameter is shortened, in some areas to even less than that in pure TiO2 anatase films. This observation was ascribed to substitution of the smaller Co3+ ions into the TiO2 anatase lattice. The EELS data confirm that Co is in either a +2 or +3 formal oxidation state in ferromagnetic Ti0.93Co0.07O2 films.
Show PACS
81.15.Fg Pulsed laser ablation deposition
75.50.Pp Magnetic semiconductors
75.50.Dd Nonmetallic ferromagnetic materials
68.37.Lp Transmission electron microscopy (TEM)
79.20.Uv Electron energy loss spectroscopy
75.30.Mb Valence fluctuation, Kondo lattice, and heavy-fermion phenomena
68.55.A- Nucleation and growth

Spectroscopic ellipsometry characterization of HfxSiyOz films using the Cody–Lorentz parameterized model

J. Price, P. Y. Hung, T. Rhoad, B. Foran, and A. C. Diebold

Appl. Phys. Lett. 85, 1701 (2004); http://dx.doi.org/10.1063/1.1784889 (3 pages) | Cited 25 times

Online Publication Date: 13 September 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A parameterized, Kramers–Kronig consistent, Cody–Lorentz optical model is used to simulate the dielectric response of thin HfxSiyOz films. Optical constants are determined in the range 0.75–8.35 eV. The Cody–Lorentz model has three specific differences when compared to the previously employed Tauc–Lorentz model: (1) weak exponential absorption below the band gap, (2) a modified joint density-of-states, and (3) a restriction on the ε1(∞) parameter. These three differences allow the Cody–Lorentz model to have an improved fit to experimental data. As a result of a more accurate optical model for HfxSiyOz, we were able to identify an interfacial layer with thickness in close agreement with transmission electron microscopy measurements. Use of the Tauc–Lorentz model when fitting the same experimental data could not identify an interfacial layer. Results are also discussed in which the Cody–Lorentz model shows sensitivity to varying degrees of silicate composition.
Show PACS
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
78.66.Nk Insulators
77.55.-g Dielectric thin films

Self-assembling in AlxGa1−xNyAs1−y alloys

V. A. Elyukhin, V. M. Sánchez-R., and O. V. Elyukhina

Appl. Phys. Lett. 85, 1704 (2004); http://dx.doi.org/10.1063/1.1789574 (3 pages) | Cited 10 times

Online Publication Date: 13 September 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The self-assembling of the isoelectronic cation impurities in lightly anion-doped AlxGa1−xNyAs1−y alloys with the zinc blende structure is predicted. The tetrahedral surroundings of Ga (Al) impurity atoms should be formed around As (N) impurity atoms in AlN-enriched (GaAs-enriched) alloys. The cation impurity concentrations for the complete Ga (Al) surroundings of all As (N) atoms are estimated at the higher growth and lower annealing temperatures. The advantage of the Al–N and Ga–As bonding over the Al–As and Ga–N bonding is an origin of the self-assembling in lightly isoelectronically-doped AlxGa1−xNyAs1−y alloys.
Show PACS
81.05.Ea III-V semiconductors
61.72.S- Impurities in crystals
61.72.Cc Kinetics of defect formation and annealing
81.40.Lm Deformation, plasticity, and creep
62.20.F- Deformation and plasticity
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close