References of "Kordoš, P"
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See detailRF small-signal and power characterization of AlGaN/GaN HEMTs
Fox, A.; Marso, Michel UL; Javorka, P. et al

in , Proc. 4th Intern. Conf. Advanced Semicon. Dev. & Microsystems (2002)

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See detailGeneration of 460 GHz radiation by photomixing in low-temperature-grown MBE GaAs
Mikulics, M.; Siebel, F.; Fox, A. et al

in Proc. 4th Intern. Conf. Advanced Semicon. Dev. & Microsystems (2002)

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See detailInvestigation of AlGaN/GaN HEMTs on Si substrate using backgating
Marso, Michel UL; Wolter, M.; Javorka, P. et al

in Physica Status Solidi C. Current Topics in Solid State Physics (2002), (1), 65-68

The influence of a substrate voltage on the dc characteristics of an AlGaN/GaN HEMT on silicon (111) substrate is investigated. This effect, known as backgating, is used to study traps that are located ... [more ▼]

The influence of a substrate voltage on the dc characteristics of an AlGaN/GaN HEMT on silicon (111) substrate is investigated. This effect, known as backgating, is used to study traps that are located between substrate and 2DEG channel. The transient of the drain current after applying a negative substrate voltage is evaluated for measurements with and without illumination. Several trap contributions are resolved by measurements at different photon energies. A photocurrent is observed up to 600 nm wavelength. Up to this wavelength the backgating effect can be compensated and the drain current restored by a short light pulse. The experiments are performed on completed HEMTs, allowing investigation of the influence of device fabrication technology. [less ▲]

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See detailGrowth and characterisation of AlGaN/GaN-HEMTs on silicon substrates,
Kalisch, H.; Dikme, Y.; Gerstenbrandt, G. et al

in Physica Status Solidi A. Applications and Materials Science (2002), 194(2), 464-467

In order to analyse and to compare the properties of AlGaN/GaN HEMT on silicon and on sapphire substrates, studies on both layers and device types have been performed. Besides the substantially lower ... [more ▼]

In order to analyse and to compare the properties of AlGaN/GaN HEMT on silicon and on sapphire substrates, studies on both layers and device types have been performed. Besides the substantially lower substrate costs compared to SiC, the use of silicon as substrate provides the advantage of a higher thermal conductivity compared to sapphire allowing a more efficient heat removal from the device and thus higher RF power densities. On silicon, up to 900 nm of GaN as well as HEMT structures have been deposited and characterised regarding their structural, optical and electrical properties. HEMT devices with various gate lengths were processed and measured onwafer under continuous and pulsed operation conditions. The properties of the layers and devices on silicon substrates are developing to become comparable to those based on sapphire and silicon carbide. [less ▲]

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See detailAlGaN/GaN HEMTs on Silicon Substrates with f¬T of 32/20 GHz and fmax of 27/22 GHz for 0.5/0.7 µm gate length,
Javorka, P.; Alam, A.; Fox, A. et al

in Electronics Letters (2002), 38(2002), 288-289

AlGaN/GaN HEMTs on silicon substrates have been realised and their static and small signal characteristics investigated. The AlGaN/GaN (x=0.23) material structures were grown on (111) p-Si by LP-MOVPE ... [more ▼]

AlGaN/GaN HEMTs on silicon substrates have been realised and their static and small signal characteristics investigated. The AlGaN/GaN (x=0.23) material structures were grown on (111) p-Si by LP-MOVPE. Devices exhibit a saturation current density of 0.53 to 0.68 A/mm and a peak extrinsic transconductance of 110 mS/mm. A unity gain frequency of 20 and 32 GHz and a maximum frequency of oscillation of 22 and 27 GHz are obtained for devices with a gate length of 0.7 and 0.5 mm, respectively. These values are the highest reported so far on AlGaN=GaN=Si HEMTs and are comparable to those known for devices using sapphire and SiC substrates. [less ▲]

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See detailAlGaN/GaN HEMTs on (111) Silicon Substrates
Javorka, P.; Alam, A.; Wolter, M. et al

in IEEE Electron Device Letters (2002), 23(2002), 4-6

AlGaN/GaN HEMTs on silicon substrates have been fabricated and their static and small-signal RF characteristics investigated. The AlGaN/GaN material structures were grown on (111) p-Si by LP-MOVPE ... [more ▼]

AlGaN/GaN HEMTs on silicon substrates have been fabricated and their static and small-signal RF characteristics investigated. The AlGaN/GaN material structures were grown on (111) p-Si by LP-MOVPE. Devices exhibit a saturation current of 0.91 A/mm, a good pinchoff and a peak extrinsic transconductance of 122 mS/mm. A unity current gain frequency of 12.5 GHz and fmax/fT=0.83 were obtained. The highest saturation current reported so far, static output characteristics of up to 20 V and breakdown voltage at pinchoff higher than 40 V demonstrate that the devices are capable of handling 16 W/mm static heat dissipation. [less ▲]

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See detailPhotoionization spectroscopy of traps in doped and undoped AlGaN/GaN HEMTs
Wolter, M.; Javorka, P.; Marso, Michel UL et al

in Physica Status Solidi C. Current Topics in Solid State Physics (2002), (1), 82-85

Deep-level defects and surface states are supposed to be responsible for the limitation of AlGaN/GaN high electron mobility transistor (HEMT) performance. In order to investigate the influence of these ... [more ▼]

Deep-level defects and surface states are supposed to be responsible for the limitation of AlGaN/GaN high electron mobility transistor (HEMT) performance. In order to investigate the influence of these traps, photoionization spectroscopy was used to study doped and undoped HEMTs grown on sapphire in different metalorganic vapour-phase epitaxy reactors. This measurement technique is based on the optical reversion of the current collapse and it allows one to determine photoionization cross-sections of the participating traps. For doped and undoped HEMTs nearly the same two defect levels with excitation energies of 3.2 eV and 2.9 eV were determined. By varying the source–gate voltage it was found that the photoionization cross-section is reduced for positive gate bias, i.e. the virtual gate on the gate–drain access region is partially neutralized due to the removal of trapped electrons from surface states. [less ▲]

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See detailLow-temperature-grown MBE GaAs for terahertz photomixers
Mikulics, M.; Marso, Michel UL; Fox, A. et al

in EDMO (2001)

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See detailOptimization of AlGaN/GaN HEMT performance
Javorka, P.; Wolter, M.; Alam, A. et al

in Proc. EDMO (2001)

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See detailInvestigation of self-heating effects in AlGaN/GaN HEMTs
Kuzmík, J.; Javorka, P.; Alam, A. et al

in Proc. EDMO (2001)

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See detailVertical Double-Gate MOSFET Based on Epitaxial Growth
Moers, J.; Trellenkamp, St; Vescan, L. et al

in Proceedings of the 31st European Solid State Devices Research Conference, Nürnberg, Germany (2001)

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See detailVaractor Diodes based on an AlGaN/GaN HEMT layer structure
Marso, Michel UL; Wolter, M.; Bernát, J. et al

in EProc. EDMO (2001)

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See detailAlGaN/GaN HEMT Optimization Using the RoundHEMT Technology
Marso, Michel UL; Javorka, P.; Alam, A. et al

in Physica Status Solidi A. Applied Research (2001), 188

The electrical characterization of epitaxially grown HEMT layer systems for device fabrication is commonly performed by Hall measurements. However, the ultimate characterization of a HEMT layer system is ... [more ▼]

The electrical characterization of epitaxially grown HEMT layer systems for device fabrication is commonly performed by Hall measurements. However, the ultimate characterization of a HEMT layer system is the transistor device itself. The RoundHEMT concept meets the need for a device technology with few fabrication steps that allows a fast feedback to epitaxy while providing an evaluation of important electrical and also processing data. Even though nearly identical Hall data on structures with different thickness and doping concentration of the AlGaN layers suggest similar device properties, the RoundHEMTs resolve remarkable differences in device performance. The best layer structure was used to fabricate HEMTs with IDS = 700 mA/mm, fT = 35 GHz, and fmax = 70 GHz for LG = 0.2 mm. [less ▲]

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See detailAlGaN/GaN Round-HEMTs on (111) silicon substrates
Javorka, P.; Alam, A.; Nastase, N. et al

in Electronics Letters (2001), 37(2001), 1364-1366

AlGaN/GaN Round-HEMTs on silicon substrates have been realised and their static characteristics investigated. The AlGaN/GaN (x = 0.23) material structures were grown on (111) p-Si by LP-MOVPE. Devices ... [more ▼]

AlGaN/GaN Round-HEMTs on silicon substrates have been realised and their static characteristics investigated. The AlGaN/GaN (x = 0.23) material structures were grown on (111) p-Si by LP-MOVPE. Devices with 0.3 mm gate length exhibit a saturation current of 0.82 A/mm, a good pinch-off and a peak extrinsic transconductance of 110 mS/mm. Highest saturation current reported so far and static output characteristics up to 20 V demonstrate that the devices are capable of handling 16 W/mm of static heat dissipation without any degradation of their performance. [less ▲]

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See detailAlGaN/GaN Varactor Diode for Integration in HEMT Circuits
Marso, Michel UL; Wolter, M.; Javorka, P. et al

in Electronics Letters (2001), 37(2001), 1476-1478

Fabrication and characterisation of metal-semiconductor-metal (MSM) diodes above an AlGaN/GaN HEMT layer system for varactor applications are reported. Device fabrication uses standard HEMT processing ... [more ▼]

Fabrication and characterisation of metal-semiconductor-metal (MSM) diodes above an AlGaN/GaN HEMT layer system for varactor applications are reported. Device fabrication uses standard HEMT processing steps, allowing integration in HEMT circuits without the need of sophisticated growth or etching techniques. Capacitancevoltage measurements exhibit CMAX/CMIN ratios up to 100, tunable by the electrode geometry. These results exceed best values for published heterostructure varactor diodes. Fabrication of AlGaN/GaN HEMTs on the same layer system with identical technology prove the potential for monolithic integration. [less ▲]

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See detailInvestigations on the influence of traps in AlGaN/GaN HEMTs
Wolter, M.; Javorka, P.; Marso, Michel UL et al

in EDMO (2001)

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See detailMaterial and Device Issues of GaN-based HEMTs
Kordoš, P.; Alam, A.; Betko, J. et al

in Proceedings of the 8th International Symposium on High Performance Electron Devices for Microwave and Optoelectronic Applications (EDMO), (2000)

Detailed reference viewed: 59 (0 UL)
See detailA Novel InAlAs/InGaAs Layer Structure for Monolithically Integrated Photoreceiver,
Hodel, U.; Orzati, A.; Marso, Michel UL et al

in Proc. 2000 Int. Conf. Indium Phosphide and Related Materials (2000)

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See detailFormation of laterally displaced porous silicon filters using different fabrication methods
Marso, Michel UL; Wolter, M.; Arens-Fischer, R. et al

in Proceedings of the 3rd International EuroConference on Advanced Semiconductor Devices and Microsystems (2000)

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See detailVertical Silicon MOSFETs based on Selective Epitaxial Growth
Moers, J.; Tönnesmann, A.; Klaes, D. et al

in Proc. 3rd International EuroConference on Advanced Semiconductor Devices and Microsystems (2000)

Detailed reference viewed: 58 (0 UL)