Boris Meyler - Academia.edu (original) (raw)

Papers by Boris Meyler

Solid-State Electronics, 1993

A~tract-A power GaAs Schottky diode (SD) with a chemically deposited Ni barrier was designed, fab... more A~tract-A power GaAs Schottky diode (SD) with a chemically deposited Ni barrier was designed, fabricated and tested. The diode has a reverse breakdown voltage VBR of 140 V, forward voltage drop V F (at 50 A/cm 2) of 0.7 V at 23°C, 0.5 V at 150°C and 0.3 V at 250°C, and reverse leakage current densities JR (at-50V) of 0.1 #A/cm 2 at 23°C and 1 mA/cm 2 at 150°C. Calculated forward and reverse I-V characteristics using a simple self-consistent computer model are in good agreement with measured values. Calculated characteristics of a silicon SD with identical structure parameters, using the same model, show much poorer VaR , V F and JR values. The theoretical maximum value of VBR is physically limited by the largest allowed V F. For a V F of-~ 1.6 V, VaR.m ~ is ~200 V in Si and-~800 V in GaAs SDs. Our relatively simple technology allows manufacturing of large area GaAs Schottky diodes with average currents up to 100A.

Journal of Applied Physics, 1994

The development of a new type of variable semiconductor capacitor is reported. Its essence is a m... more The development of a new type of variable semiconductor capacitor is reported. Its essence is a monolithic (or hybrid) GaAs structure consisting of a reverse biased, high voltage, low reverse current Schottky diode connected in series (back-to-back) to a forward biased PiN diode. The PiN diode has an i layer with a net doping concentration (Nd-Na)i of less than 5×1011 cm−3 and a width of between 3 and 70 μm. The principle of operation is based mainly on control of the PiN diode diffusion capacitance by the reverse Schottky diode current. This current can be changed by structural design or by light. Experimental parameters of a light controlled capacitor include Cmax/Cmin ratios of 20 at ∼1 V and 4–5 at 35 V and a ΔC/ΔV slope of ∼2000 pF/V.

Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena, 2009

The authors developed a new Al2O3–SiO2 (A-O) stack for application as a high voltage complementar... more The authors developed a new Al2O3–SiO2 (A-O) stack for application as a high voltage complementary metal oxide semiconductor (CMOS) dielectric and/or top oxide in electrically erasable programmable read only memory floating gate and polysilicon-oxide-nitride-oxide-silicon embedded memories in advanced technology nodes. An amorphous atomic layer deposited alumina is doped with nitrogen and transformed into the crystalline phase by further rapid thermal process annealing. The 65Å effective oxide thickness (EOT) stack allows operating voltages twice exceeding the values for thermal SiO2 of the same EOT, has extremely low leakage currents, has negligible charge trapping, and is immune to degradation. Moreover, after alumina removal, the remaining strongly nitrided bottom oxide layer can be used as the gate dielectric of CMOS devices.

ECS Journal of Solid State Science and Technology, 2017

The influence of various radiations on the performance and carrier transport properties of AlGaN/... more The influence of various radiations on the performance and carrier transport properties of AlGaN/GaN HEMTs have been observed at length over the previous few decades. Gamma irradiation has been shown to have little influence on carrier density but has significant effects on device performance. The effects of gamma irradiation have proven non-monotonic in nature, dividing results into low and high doses with an inflection point near 300 Gy. Low doses of gamma irradiation have a tendency to improve device characteristics, while high doses lead to device degradation. The differences in low versus high doses are highlighted by electron beam induced current and dc characterizations. The variance in behavior originates from irradiation-induced trap generation and subsequent trap occupation from Compton scattering. AlGaN/GaN-based HEMTs have shown carrier transport enhancement for low doses.

IEEE Transactions on Nanotechnology, 2016

We describe the optical properties of nonvolatile memory cells based on metal-insulator-semicondu... more We describe the optical properties of nonvolatile memory cells based on metal-insulator-semiconductor structures with embedded Pt nanoparticles, fabricated by atomic layer deposition. We show the effect of illumination on the static as well as dynamic properties of two devices, which differ by their respective thicknesses of the tunneling layer. The device with the thicker tunneling layer exhibits a faster response under illumination and significantly better retention properties, while the device with the thinner tunneling layer is faster under dark conditions.

Physical Review B, 2000

An exponential dependence of the photoconductivity on the surface photovoltage at GaN layers is p... more An exponential dependence of the photoconductivity on the surface photovoltage at GaN layers is predicted theoretically and confirmed experimentally. The prediction is based on the assumption that the material is mainly an ordered polycrystal, consisting of columnar grains. Accordingly, transport is expected to be limited by potential barriers at the grain boundaries, arising from the charge trapped at grain-boundary defects. The observed exponential dependence provides evidence that strongly supports the model by establishing a direct link between the bulk conductivity and the surface potential barrier. The same model is shown to successfully explain several other defect-related findings as well.

CLEO:2011 - Laser Applications to Photonic Applications, 2011

ABSTRACT A single crystal diamond nanobeam with a triangular cross-section and 1D-Bragg reflector... more ABSTRACT A single crystal diamond nanobeam with a triangular cross-section and 1D-Bragg reflectors is reported. Modeling shows Q≈2.5×106, Vm=1.06×(λ/n)3. A low-Q cavity version was fabricated by Focused-Ion-Beam, exhibiting a clear mode confinement spectrum.

ECS Transactions, 2009

We describe a new, all high-k, nonvolatile MIS memory capacitor with an equivalent oxide thicknes... more We describe a new, all high-k, nonvolatile MIS memory capacitor with an equivalent oxide thickness of 7.3 nm that makes use of two gold nanocrystal charge storage layers. The device exhibits a large memory hysteresis of about 0.75 V and 15 V, respectively at a sweeping gate voltages of 1V and +11V to -8V with a maximum storage charge density of ~2.75e13 cm^-2. The leakage current density is 3.6e-5 A/cm^2 at -10 V and the breakdown voltage is in the range of 12.3V - 13.3V. A large memory hysteresis window of ~10 V was also observed after more than 10 hours of consecutive write / erase operations with a +-7 V swing.

Conference on Lasers and Electro-Optics 2010, 2010

... Following the Finite-Difference-Time-Domain (FDTD) analysis the expected quality factor is Q≈... more ... Following the Finite-Difference-Time-Domain (FDTD) analysis the expected quality factor is Q≈770 at the ... to the calculated one, which may suggest high material quality in terms of optical losses. ... In this talk we will give a detailed analysis of cavity mode wavelength and quality ...

physica status solidi (c), 2003

ABSTRACT High quality AlN thin films were grown by Low Pressure Organometallic Vapor Phase Epitax... more ABSTRACT High quality AlN thin films were grown by Low Pressure Organometallic Vapor Phase Epitaxy(LP-OMVPE) on sapphire and Si substrates. oxygen contamination in the Al layers can be reduced drastically by fine tuning of the growth parameters, by avoiding O-containing substrates, and by using a cap GaN layer. AlN films grown on Si, exhibiting oxygen concentration levels of [O] ≤ 1019 cm−3, display an X-Ray Diffraction Full Width Half Maximum (FWHM) of 190 arcsec and an extremely sharp near band-edge cathodoluminescence emission at 5.925 eV with FWHM of 30 meV and 5.975 eV (unresolved). (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

physica status solidi (a), 1999

The effect of grain boundaries on electrical properties of thin GaN layers is studied by photocon... more The effect of grain boundaries on electrical properties of thin GaN layers is studied by photoconductivity and its functional dependence on surface photovoltage, and by resistance changes produced by ion implantation damage. These two independent experiments provide strong evidence that the conductivity in GaN can be described by the Grain Boundary Controlled Transport model. According to this model, charged interface states at the grain boundaries form potential barriers for inter-grain conduction.

New Journal of Physics, 2011

Diamond photonics provides an attractive architecture to explore room temperature cavity quantum ... more Diamond photonics provides an attractive architecture to explore room temperature cavity quantum electrodynamics and to realize scalable multi-qubit computing. Here we review the present state of diamond photonic technology. The design, fabrication and characterization of a novel triangular cross section nanobeam cavity produced in a single crystal diamond is demonstrated. The present cavity design, based on a triangular cross section allows vertical confinement and better signal collection efficiency than that of slab-based nanocavities, and eliminates the need for a pre-existing membrane. The nanobeam is fabricated by Focused-Ion-Beam (FIB) patterning. The cavity is characterized by a confocal photoluminescence. The modes display quality factors of Q ~220 and are deviated in wavelength by only ~1.7nm from the NVcolor center zero phonon line (ZPL). The measured results are found in good agreement with 3D Finite-Difference-Time-Domain (FDTD) calculations. A more advanced cavity design with Q=22,000 is modeled, showing the potential for high-Q implementations using the triangular cavity design. The prospects of this concept and its application to spin nondemolition measurement and quantum computing are discussed.

Materials Science and Engineering: A, 2001

In this work, a novel method for GaN layer optimization — statistical multi-parameter design of e... more In this work, a novel method for GaN layer optimization — statistical multi-parameter design of experiments (DOE) — is presented. According to the statistical model obtained, increasing the buffer layer V/III ratio is beneficial for minimizing the full width at half maximum (FWHM) of the X-ray diffraction rocking curve for the (002) reflection. Statistical models were also obtained for background

Journal of Electronic Materials, 2003

Journal of Electronic Materials, 2006

Spatially, spectrally, and depth-resolved cathodoluminescence (CL) measurements were performed fo... more Spatially, spectrally, and depth-resolved cathodoluminescence (CL) measurements were performed for high-quality thin AlN films grown on Si(111). CL spectra exhibited a sharp peak at 5.960 eV, corresponding to the near-band-edge excitonic emission of AlN. Depth-resolved CL analysis showed that deep level oxygen and carbon impurities are localized primarily at the AlN/Si interface and AlN outer surface. Monochromatic CL imaging of the near-band-edge emission exhibits a spotty pattern, which corresponds to high concentrations of threading dislocations and thermally induced microcracks in the thin layers. We have examined relief of the thermal stress in close proximity to single microcracks and intersecting microcracks. Local CL spectra acquired with a focused e-beam show blue-shifts as large as ;82 meV in the AlN nearband edge excitonic peaks, reflecting defect-induced reductions in the biaxial thermal stress, which has a maximum value of ;47 kbar.

Journal of The Electrochemical Society, 2010

... The weak Ga signal is due to ion implantation during the FIB process. ... the sign of the sto... more ... The weak Ga signal is due to ion implantation during the FIB process. ... the sign of the storage charges injected from the Si substrate under positive (electrons) and negative (holes) bias ... improve the device so that it will be usable in multilevel charge storage high density memories ...

Journal of Crystal Growth, 2002

GaN was grown by metal organic chemical vapor deposition (MOCVD) on plain Si-on-insulator (SOI) s... more GaN was grown by metal organic chemical vapor deposition (MOCVD) on plain Si-on-insulator (SOI) substrates, and on SOI which was pre-patterned for lateral confined epitaxy (LCE), with square mesas, separated by dip trenches. It was found that GaN films grown on plain SOI exhibit reduced crack density. Moreover, using LCE on SOI substrates dramatically increases the crack-free area of the

$Research paper thumbnail of Dependence of the refractive index of AlxGa1−xN on temperature and composition at elevated temperatures$

Journal of Applied Physics, 2001

ABSTRACT The refractive index of hexagonal AlxGa1−xN at room temperature and its temperature depe... more ABSTRACT The refractive index of hexagonal AlxGa1−xN at room temperature and its temperature dependence at elevated temperatures have been determined with high accuracy by spectroscopic ellipsometry. Measurements have been conducted on samples with aluminum molar fractions ranging from 0% to 65% and at temperatures between 290 and 580 K. The refractive index in the transparent spectral region has been determined as a function of photon energy, using the Kramers–Kronig relations with suitable approximations, and applying a multilayer model. An analytical expression for the composition and temperature dependent refractive index in the transparent region, above room temperature, has been obtained. The refractive index has been found to increase with increasing temperature. The shift of the refractive index is strongest for GaN and decreases for AlGaN with increasing aluminum molar fraction. The impact on the properties of GaN based waveguides is illustrated by a slab waveguide calculation. © 2001 American Institute of Physics.

Journal of Applied Physics, 2013

Thin dielectric layers are a prominent route to control the band alignments and effective work fu... more Thin dielectric layers are a prominent route to control the band alignments and effective work function of metal oxide semiconductor (MOS) devices. In this work, the electrostatic effects of thin Ta 2 O 5 layers on the band alignments of MOS devices are examined. A detailed analysis of the physical properties of a thick ($6 nm) Ta 2 O 5 layer is reported. No significant dipoles at Ta 2 O 5-Al 2 O 3 and Ta 2 O 5-SiO 2 interfaces are found, as well as any significant charges inside Ta 2 O 5 layers. When positioned at the interface, Ta 2 O 5 is shown to prevent the formation of band offsets between Al 2 O 3-SiO 2 , resulting in a shift of 1 6 0.2 eV versus samples without interfacial Ta 2 O 5. The relatively large magnitude of this shift in the current experimental configuration compared to previous works may indicate the participation of interface charges in the band offset. The possible use for these effects in devices is discussed. V

Diamond and Related Materials, 2011

The realization of photonic crystals (PC) in diamond is of major importance for the entire field ... more The realization of photonic crystals (PC) in diamond is of major importance for the entire field of spintronics based on fluorescent centers in diamond. The processing steps for the case of diamond differ from those commonly used, due to the extreme chemical and mechanical properties of this material. The present work summarizes the state of the art in the realization of PC's in diamond. It is based on the creation of a free standing diamond membrane into which the desired nano-sized patterns are milled by the use of Focused-Ion-Beam (FIB). The optimal fabrication-oriented structure parameters are predicted by simulations. The milling strategies, the method of formation the diamond membrane, recipes for dielectric material-manipulation in FIB and optical characterization constraints are discussed in conjunction with their implication on PC cavity design. The thus produced structures are characterized via confocal photoluminescence.