Search results for: A.M. Dabiran

Items from 1 to 15 out of 15 results

article

Recessed 70-nm Gate-Length AlGaN/GaN HEMTs Fabricated Using an $\hbox{Al}_{2}\hbox{O}_{3}/\hbox{SiN}_{x}$ Dielectric Layer

Donghyun Kim, V. Kumar, Jaesun Lee, Minjun Yan, more

IEEE Electron Device Letters > 2009 > 30 > 9 > 913 - 915

In this letter, a novel process for recessed-gate AlGaN/GaN high-electron-mobility transistors using an Al₂O₃/SiNx dielectric has been developed. The Al₂O₃/SiNx dielectric bilayer was used as a recess etch-mask for short-gate-footprint definition. Recessed-gate devices with a gate length of 70 nm have been fabricated on a molecular-beam-epitaxy-grown layer structure using this process. After the removal...

article

Injection and Avalanche Electroluminescence of $\hbox{Al}_{\hbox{0.1}} \hbox{Ga}_{\hbox{0.9}} \hbox{N/Al}_{\hbox{0.15}} \hbox{Ga}_{\hbox{0.85}} \hbox{N}$ Multiple Quantum Wells

Sheng-Kun Zhang, Wubao Wang, R.R. Alfano, A.M. Dabiran, more

IEEE Journal of Selected Topics in Quantum Electronics > 2008 > 14 > 4 > 1010 - 1013

Three periods of Al_0.1Ga_0.9N/Al_0.15Ga_0.85 N multiple quantum wells (MQWs) were used as the active region of a p-i-n diode fabricated on 6H-SiC substrate. Electroluminescence (EL) of these MQWs has been investigated in both injection and avalanche modes. Band-to-band luminescence of the Al_0.1Ga_0.9N wells was found to peak at 364 nm in the injection mode and in the range of 364-372 nm in the avalanche...

article

Optical and morphological properties of MBE grown wurtzite CdxZn1−xO thin films

J.W. Mares, F.R. Ruhge, A.V. Thompson, P.G. Kik, more

Optical Materials > 2007 > 30 > 2 > 346-350

Wurtzite Cd _x Zn _1−x O epilayers with cadmium concentrations ranging from x=0.02 to 0.30 were investigated using photoluminescence, transmission/reflection spectroscopy, and atomic force microscopy. The Cd _x Zn _1−x O photoluminescence peak was found to shift through the visible region from 421 (2.95eV) to 619nm (2.0eV) as the cadmium concentration was increased from...

article

ALD AI/sub 2/O/sub 3/ passivated MBE-grown AIGaN/GaN HEMTs on 6H-SiC

D.h. Kim, V. Kumar, G. Chen, A.M. Dabiran, more

Electronics Letters > 2007 > 43 > 2 > 129 - 130

article

Temperature dependence of pnp GaN/InGaN HBT performance

K.P. Lee, A.M. Dabiran, P.P. Chow, A. Osinsky, more

Solid State Electronics > 2004 > 48 > 1 > 37-41

The effects of partial ionization of Mg acceptors in the emitter and collector of pnp GaN/InGaN heterojunction bipolar transistors were investigated by simulations with a drift-diffusion model. The contact resistances are all significantly decreased at high temperatures where ionization efficiency is maximized. The cut-off frequency f _T , is predicted to be >45 GHz at 700 K at high V ...

article

Uniformity of dc and rf performance of MBE-grown AlGaN/GaN HEMTS on HVPE-grown buffers

J.K. Gillespie, R.C. Fitch, N. Moser, T. Jenkins, more

Solid State Electronics > 2003 > 47 > 10 > 1859-1862

AlGaN/GaN high electron mobility transistors (HEMTs) were grown by molecular beam epitaxy (MBE) on 2 in. diameter GaN buffer layers grown by hydride vapor epitaxy (HVPE) on sapphire substrates. HEMTs with 1 μm gate length displayed excellent dc and rf performance uniformity with up to 258 separate devices measured for each parameter. The drain-source saturation current was 561 mA with a standard deviation...

article

Simulations of InGaN-base heterojunction bipolar transistors

K.P. Lee, F. Ren, S.J. Pearton, A.M. Dabiran, more

Solid State Electronics > 2003 > 47 > 6 > 1009-1014

GaN/InGaN heterojunction bipolar transistors (HBTs) are very promising for high speed, high power density applications at elevated temperatures. In this paper we report on simulations of the dc performance of GaN/In ₀ _. ₂ Ga ₀ _. ₈ N HBTs as a function of the layer design and doping levels. The conductivity of p-InGaN is significantly lower than p-GaN, reducing the deleterious...

article

Effects of base structure on performance of GaN-based heterojunction bipolar transistors

K.P. Lee, F. Ren, S.J. Pearton, A.M. Dabiran, more

Solid State Electronics > 2003 > 47 > 6 > 1031-1036

Different base layer designs for npn GaN-based heterojunction bipolar transistors (HBTs) were simulated using a drift-diffusion transport model. The use of AlGaN/GaN superlattice bases did not produce working devices for any of the conditions investigated. InGaN/GaN base layers did produce acceptable dc current gains by enhancing electron transport. Grading of the InGaN layer composition produced...

article

0.15 μm gate-length AlGaN/GaN HEMTs with varying gate recess length

A. Kuliev, V. Kumar, R. Schwindt, D. Selvanathan, more

Solid State Electronics > 2003 > 47 > 1 > 117-122

The effect of gate-recess length on DC and RF performance of AlGaN/GaN gate-recessed high electron mobility transistors (HEMTs) was studied. 0.15 μm gate-length AlGaN/GaN HEMTs with varying gate-recess length from 0.5 to 1.0 μm were fabricated. DC and microwave performance did not exhibit significant dependence on the gate-recess length. The devices showed a maximum drain current density as high as...

article

Surface passivation of AlGaN/GaN HEMTs using MBE-grown MgO or Sc ₂ O ₃

B. Luo, J.W. Johnson, B.P. Gila, A. Onstine, more

Solid State Electronics > 2002 > 46 > 4 > 467-476

Thin (100 Å) layers of MgO or Sc ₂ O ₃ grown by molecular beam epitaxy were investigated for surface passivation of AlGaN/GaN high electron mobility transistors. A variety of pre-treatments such as UV/O ₃ or in situ heating were employed prior to the dielectric deposition. Under optimized conditions, the MgO produced an increase in drain-source current, threshold voltage and...

article

Effect of gate length on DC performance of AlGaN/GaN HEMTs grown by MBE

J.W. Johnson, A.G. Baca, R.D. Briggs, R.J. Shul, more

Solid State Electronics > 2001 > 45 > 12 > 1979-1985

The DC performance of AlGaN/GaN high electron mobility transistors grown by plasma-assisted molecular beam epitaxy was investigated for gate lengths in the range 0.1-1.2 μm. On 0.25 μm gate length devices we obtained 40 V _D _S operation with >50 mA peak I _D . The peak drain current density was 0.44 A/mm for 100 μm gate width devices with 1.2 μm gate lengths. The extrinsic transconductance...

article

Step edge barriers versus step edge relaxation in GaAs:Sn molecular beam epitaxy

A.M. Dabiran, S.M. Seutter, S. Stoyanov, M.C. Bartelt, more

Surface Science > 1999 > 438 > 1-3 > 131-141

Sn strongly segregates to the surface during MBE growth. We have previously proposed a microscopic mechanism for this process in which Sn can incorporate into either a substitutional site or into a surface interstitial site. These two sites compete with each other resulting in two main effects: (1) strain causes an initial surface roughening that has a characteristic length of 1000nm and a corrugation...

article

Nucleation, growth and magnetic properties of epitaxial FeAl films on AlAs/GaAs

B.E. Ishaug, S.M. Seutter, A.M. Dabiran, P.I. Cohen, more

Surface Science > 1997 > 380 > 1 > 75-82

An investigation of the nucleation and growth as well as magnetic properties of epitaxial Fe_xAl_{1 − x} on AlAs/GaAs(100) is reported. In situ RHEED and UHV STM were used to characterize the surface and ex situ MOKE measurements were used to characterize the magnetic properties. We found that epitaxial films can be grown over a broad composition range, 0.5 < x < 0.8, provided the appropriate nucleation...

article

Surface reconstructions and growth mode transitions of AlAs(100)

A.M. Dabiran, P.I. Cohen

Journal of Crystal Growth > 1995 > 150 > 1-4 Proceedings Part 1 > 23-27

The surface reconstructions of AlAs(100) layers grown by molecular beam epitaxy (MBE) on GaAs(100) were mapped as a function of substrate temperature and arsenic flux. Three main reconstructions were observed - a c(4x4) at lower temperatures and higher arsenic fluxes, a (2x4) at middle temperatures, and a (3x2) at higher temperatures and lower arsenic fluxes. Growth of AlAs on AlAs(100) is layer-by-layer...

article

Surface reconstructions and growth mode transitions of AlAs(100)

A.M. Dabiran, P.I. Cohen

Journal of Crystal Growth > 1995 > 150 > Part 1 > 23-27

The surface reconstructions of AlAs(100) layers grown by molecular beam epitaxy (MBE) on GaAs(100) were mapped as a function of substrate temperature and arsenic flux. Three main reconstructions were observed - a c(4 x 4) at lower temperatures and higher arsenic fluxes, a (2 x 4) at middle temperatures, and a (3 x 2) at higher temperatures and lower arsenic fluxes. Growth of AlAs on AlAs(100) is layer-by-layer...

Filter options

Publication date

Set your own date range

INFONA - science communication portal

Search results for: A.M. Dabiran

Add recipient

Sending message cancelled

Are you sure you want to cancel sending this message?

Send message

Filter options

Publication date

Date range setting

Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.

Keywords

Data set

Journal

Reporting an error / abuse

Sending the report failed

Accessibility options