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

1 Mar 2004

Volume 84, Issue 9, pp. 1435-1613

Issue Cover Spotlight Figure

Appl. Phys. Lett. 84, 1558 (2004); http://dx.doi.org/10.1063/1.1651641 (3 pages)

DongWeon Lee, Adrian Wetzel, Roland Bennewitz, Ernst Meyer, Michel Despont, Peter Vettiger, and Christoph Gerber
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Properties of Ir-based Ohmic contacts to AlGaN/GaN high electron mobility transistors

R. C. Fitch, J. K. Gillespie, N. Moser, T. Jenkins, J. Sewell, D. Via, A. Crespo, A. M. Dabiran, P. P. Chow, A. Osinsky, J. R. La Roche, F. Ren, and S. J. Pearton

Appl. Phys. Lett. 84, 1495 (2004); http://dx.doi.org/10.1063/1.1651649 (3 pages) | Cited 12 times

Online Publication Date: 25 February 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Measurement of the electrical characteristics of 250 devices on the same 2 in. diameter wafer shows that Ti/Al/Ir/Au Ohmic contacts on AlGaN/GaN high electron mobility transistors (HEMTs) have lower average specific contact resistance after annealing at 850 °C for 30 s (4.6×10−5 Ω cm2) compared to more standard Ti/Al/Ni/Au contacts (2×10−4 Ω cm2). HEMTs with these Ir-based contacts also show average interdevice isolation currents approximately a factor of 2 lower, higher peak transconductance (134 mS/mm compared to 121 mS/mm), and higher device breakdown voltage (31 V compared to 23 V) than the devices with Ni-based contacts. This Ir-based contact metallurgy looks promising for applications requiring extended thermal stability of the HEMTs. © 2004 American Institute of Physics.
Show PACS
85.30.Tv Field effect devices
73.40.Cg Contact resistance, contact potential
61.72.Cc Kinetics of defect formation and annealing
81.05.Ea III-V semiconductors

Effect of nitric oxide annealing on the interface trap density near the conduction bandedge of 4H–SiC at the oxide/(11math0) 4H–SiC interface

S. Dhar, Y. W. Song, L. C. Feldman, T. Isaacs-Smith, C. C. Tin, J. R. Williams, G. Chung, T. Nishimura, D. Starodub, T. Gustafsson, and E. Garfunkel

Appl. Phys. Lett. 84, 1498 (2004); http://dx.doi.org/10.1063/1.1651325 (3 pages) | Cited 25 times

Online Publication Date: 25 February 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Nitric oxide postoxidation anneal results in a significant decrease of defect state density (Dit) near the conduction bandedge of n-4H–SiC at the oxide/(11math0) 4H–SiC interface. Comparison with measurements on the conventional (0001) Si-terminated face shows a similar interface state density following passivation. Medium energy ion scattering provides a quantitative measure of nitrogen incorporation at the SiO2/SiC interface. © 2004 American Institute of Physics.
Show PACS
73.20.Hb Impurity and defect levels; energy states of adsorbed species
61.72.Cc Kinetics of defect formation and annealing
81.65.Mq Oxidation
81.65.Rv Passivation
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
68.49.Sf Ion scattering from surfaces (charge transfer, sputtering, SIMS)

Electrical properties of Pt contacts on p-GaN activated in air

Yow-Jon Lin and Kuo-Chen Wu

Appl. Phys. Lett. 84, 1501 (2004); http://dx.doi.org/10.1063/1.1651658 (3 pages) | Cited 6 times

Online Publication Date: 25 February 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this study, the electrical properties of Pt contacts on p-type GaN (p-GaN) activated in air were investigated. From the observed photoluminescence result, it is suggested that the hydrogenated Ga vacancies (i.e., VGaH2) were formed during the activation process. However, VGaH2 in p-GaN near the surface was transformed into VGa after Pt deposition, because Pt strongly absorbed hydrogen. A large number of VGa at the Pt/p-GaN interface would lead to the pinning of the Fermi level at 0.3 eV above the valence-band edge, as well as the formation of the low barrier at the interface, and the formation of the nonalloyed ohmic contacts due to the occurrence of the tunneling transmission for holes at the interface. © 2004 American Institute of Physics.
Show PACS
81.05.Ea III-V semiconductors
73.40.Ns Metal-nonmetal contacts
78.55.Cr III-V semiconductors

Low resistance and transparent Ni–La solid solution/Au ohmic contacts to p-type GaN

June-O Song, Dong-Seok Leem, J. S. Kwak, S. N. Lee, O. H. Nam, Y. Park, and Tae-Yeon Seong

Appl. Phys. Lett. 84, 1504 (2004); http://dx.doi.org/10.1063/1.1652238 (3 pages) | Cited 9 times

Online Publication Date: 25 February 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on the formation of reliable Ni–La solid solution (8 nm)/Au (8 nm) ohmic contacts to p-type GaN (Na = 5×1017 cm−3). The as-deposited contact reveals nonlinear current–voltage (I–V) characteristics. However, the contacts show considerably improved I–V behavior when annealed at temperatures of 350–550 °C for 1 min in air ambient. For example, the specific contact resistance as low as 7.2×10−5 Ω cm2 is obtained from the samples annealed at 550 °C, whose transmittance is measured to be 82.5% at a wavelength of 470 nm. Based on Auger electron spectroscopy and x-ray photoemission spectroscopy results, possible ohmic formation mechanisms for the annealed contacts are described and discussed. © 2004 American Institute of Physics.
Show PACS
73.40.Cg Contact resistance, contact potential
73.40.Ns Metal-nonmetal contacts
61.72.Cc Kinetics of defect formation and annealing
79.20.Fv Electron impact: Auger emission

Electron scattering in AlGaN/GaN structures

S. Syed, M. J. Manfra, Y. J. Wang, R. J. Molnar, and H. L. Stormer

Appl. Phys. Lett. 84, 1507 (2004); http://dx.doi.org/10.1063/1.1655704 (3 pages) | Cited 18 times

Online Publication Date: 25 February 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present data on mobility lifetime τt, quantum lifetime τq, and cyclotron resonance lifetime τCR, of a sequence of high-mobility two-dimensional electron gases in the AlGaN/GaN system, covering a density range of 1 to 4.5×1012 cm−2. We observe a large discrepancy between τq and τCR(τq ∼ τCR/6), and explain it as the result of density fluctuations of only a few percent. Therefore, only τCR—and not τq—is a reliable measure of the time between electron-scattering events in these specimens. The ratio τt/τCR increases with increasing density in this series of samples, but scattering over this density range remains predominantly in the large-angle scattering regime. © 2004 American Institute of Physics.
Show PACS
72.20.Fr Low-field transport and mobility; piezoresistance
72.20.My Galvanomagnetic and other magnetotransport effects
68.35.Ct Interface structure and roughness
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
73.20.At Surface states, band structure, electron density of states

Self-assembled InAsSb quantum dots on (001) InP substrates

Yueming Qiu and David Uhl

Appl. Phys. Lett. 84, 1510 (2004); http://dx.doi.org/10.1063/1.1655690 (3 pages) | Cited 20 times

Online Publication Date: 25 February 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Self-assembled InAsSb quantum dots (QD) on (001) InP substrates have been grown using metalorganic vapor phase epitaxy. The dot density and size are found to be strongly dependent on the presence of arsine. Direct deposition of InSb on InP and GaSb substrates formed large islands of InSb with low density of less than 5×109/cm2, however, InAsSb QDs of density as high as 4×1010/cm2 could be self-assembled by alternating group III and group V precursors, and high density almost pure InSb QDs were achieved on In0.53Ga0.47As/InP. The formation of high density InAsSb QDs is a result of a local nonequilibrium process and a reduction in mobility of In adatoms on the growth surface due to the presence of arsenic atoms, and in the case of high density almost pure InSb QDs on InGaAs/InP, the InAs interface layer is believed to be responsible. Photoluminescence shows that InSb QDs emit light at room temperature in the range of 1.7–2.2 μm. © 2004 American Institute of Physics.
Show PACS
68.65.Hb Quantum dots (patterned in quantum wells)
78.55.Cr III-V semiconductors
78.66.Fd III-V semiconductors
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
78.67.Hc Quantum dots

Highly-efficient blue electroluminescence based on two emitter isomers

Ying Kan, Liduo Wang, Lian Duan, Yuanchuan Hu, Guoshi Wu, and Yong Qiu

Appl. Phys. Lett. 84, 1513 (2004); http://dx.doi.org/10.1063/1.1651653 (3 pages) | Cited 39 times

Online Publication Date: 25 February 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Highly-efficient blue organic light-emitting devices with a nondoped device structure have been fabricated with two anthracene derivatives, 2,3,6,7-tetramethyl-9,10-(1-dinaphthyl)-anthracene (α-TMADN) and 2,3,6,7-tetramethyl-9,10-(2-dinaphthyl)-anthracene (β-TMADN). The homemade α-TMADN, β-TMADN, or their blend were used as the light-emitting materials, and 4,7-diphenyl-1,10-phenanthroline was used as the hole blocking and electron transporting material, N,N′-biphenyl-N,N′-bis-(1-naphenyl)-[1,1′-biphenyl]-4,4′-diamine was used as the hole transporting material. The brightness of the device with β-TMADN as the light-emitting material is up to 10 000 cd/m2 at 12 V with the maximum efficiency of 4.5 cd/A, which is better than that of the device with α-TMADN as the light-emitting material. The brightness of the same structure device with the blend of α-TMADN and β-TMADN as the light-emitting material, in which the ratio of α-TMADN to β-TMADN is 9:1, is more than 12 000 cd/m2 at 15 V with the maximum efficiency of 5.2 cd/A. © 2004 American Institute of Physics.
Show PACS
85.60.Jb Light-emitting devices
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close