Wyniki wyszukiwania - Biblioteka Nauki

1

High Quality Gate Insulator/GaN Interface for Enhancement-Mode Field Effect Transistor

100%

Taube A. , Kruszka R. , Borysiewicz M. , Gierałtowska S. , Kamińska E. , Piotrowska A.

Acta Physica Polonica A

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2011

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tom 120

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nr 6A

A-22-A-24

EN

The capacitance-voltage measurements were applied for characterization of the semiconductor/dielectric interface of GaN MOS capacitors with SiO_2 and HfO_2/SiO_2 gate stacks. From the Terman method low density of interface traps (D_{it} ≈ 10^{11} eV^{-1} cm^{-2}) at SiO_2/GaN interface was calculated for as-deposited samples. Samples with HfO_2/SiO_2 gate stacks have higher density of interface traps as well as higher density of mobile charge and effective charge in the dielectric layers. High quality of SiO_2/GaN interface shows applicability of SiO_2 as a gate dielectric in GaN MOSFET transistors.

2

Zinc Oxide Semiconductor for Photonics Structures Applications

84%

Struk P. , Pustelny T. , Pustelny B. , Gołaszewska K. , Kamińska E. , Piotrowska A. , Borysiewicz M. , Ekielski M.

Acta Physica Polonica A

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2010

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tom 118

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nr 6

1242-1245

EN

The paper presents investigations concerning the analysis of photonic structures with grating couplers. In the paper basic theoretically information on photonic structures with grating couplers is presented. The results of numerical investigations on photonic structures with grating couplers are discussed, too. Investigations show an essential influence of the geometrical parameters of grating couplers on the effectiveness of the input and output of optic power into and out of this photonic structure. In the paper the selected results of experimental realizations of photonic structures with grating couplers based on zinc oxide ZnO are presented.

3

Technology of Ultrathin NbN and NbTiN Films for Superconducting Photodetectors

67%

Guziewicz M. , Slysz W. , Borysiewicz M. , Kruszka R. , Sidor Z. , Juchniewicz M. , Golaszewska K. , Domagala J. , Rzodkiewicz W. , Ratajczak J. , Bar J. , Wegrzecki M. , Sobolewski R.

Acta Physica Polonica A

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2011

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tom 120

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nr 6A

A-76-A-79

EN

We report fabrication and characterization of ultrathin NbN and NbTiN films designed for superconducting photodetectors. Our NbN and NbTiN films were deposited on Al_2O_3 and Si single-crystal wafers by a high-temperature, reactive magnetron sputtering method and, subsequently, annealed at 1000°C. The best, 18 nm thick NbN films deposited on sapphire exhibited the critical temperature of 15.0 K and the critical current density as high as ≈ 8 × 10^6 A/cm^2 at 4.8 K.

4

Capability of Semiconducting NiO Films in Gamma Radiation Dosimetry

67%

Guziewicz M. , Jung W. , Grochowski J. , Borysiewicz M. , Golaszewska K. , Kruszka R. , Baranska A. , Piotrowska A. , Witkowski B. , Domagala J. , Gryzinski M. , Tyminska K. , Stonert A.

Acta Physica Polonica A

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2011

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tom 120

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nr 6A

A-69-A-72

EN

Electrical properties of RF magnetron sputtered p-NiO films were characterized after fabrication and after gamma irradiations using ^{137}Cs and ^{60}Co sources. Electrical parameters are obtained from the Hall measurements, impedance spectroscopy and C-V measurement of n-Si/p-NiO junction diodes. The results show that resistivity of the NiO film is gradually increased following after sequential irradiation processes because of the decrease in holes' concentration. Hole concentration of a NiO film decreases from the original value of 4.36 × 10^{16} cm^{-3} to 2.86 × 10^{16} cm^{-3} after ^{137}Cs γ irradiation with doses of 10 Gy. In the case of γ irradiation from ^{60}Co source, hole concentration of the film decreases from 6.3 × 10^{16}/cm^3 to 4.1 × 10^{16}/cm^3 and to 2.9 × 10^{16}/cm^3 after successive expositions with a dose of 20 Gy.

5

Planar Optical Waveguides for Application in Optoelectronic Gas Sensors

67%

Golaszewska K. , Kamińska E. , Pustelny T. , Struk P. , Piotrowski T. , Piotrowska A. , Ekielski M. , Kruszka R. , Wzorek M. , Borysiewicz M. , Pasternak I. , Gut K.

Acta Physica Polonica A

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2008

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tom 114

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nr 6A

A-223-A-230

EN

In the paper, the results of technological investigations on planar optical waveguides based on high band gap oxide semiconductors were presented. Investigations concerned the technologies of depositing very thin layers of: zinc oxide ZnO, titanium dioxide TiO_2 and tin dioxide SnO_2 on substrates of quartz glass plates. There were investigated both morphological structures of the produced layers and their optical properties. The paper also presents investigations on the technology of input-output light systems in the Bragg grating structures.

6

Ultrathin NbN Films for Superconducting Single-Photon Detectors

67%

Słysz W. , Guziewicz M. , Borysiewicz M. , Domagała J. , Pasternak I. , Hejduk K. , Rzodkiewicz W. , Ratajczak J. , Bar J. , Węgrzecki M. , Grabiec P. , Grodecki R. , Węgrzecka I. , Sobolewski R.

Acta Physica Polonica A

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2011

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tom 120

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nr 1

200-203

EN

We present our research on fabrication and structural and transport characterization of ultrathin superconducting NbN layers deposited on both single-crystal Al_2O_3 and Si wafers, and SiO_2 and Si_3N_4 buffer layers grown directly on Si wafers. The thicknesses of our films varied from 6 nm to 50 nm and they were grown using reactive RF magnetron sputtering on substrates maintained at the temperature 850°C. We have performed extensive morphology characterization of our films using the X-ray diffraction method and atomic force microscopy, and related the results to the type of the substrate used for the film deposition. Our transport measurements showed that even the thinnest, 6 nm thick NbN films had the superconducting critical temperature of 10-12 K, which was increased to 14 K for thicker films.