Thomas Rodle - Academia.edu (original) (raw)

Papers by Thomas Rodle

Research paper thumbnail of Reliability status of GaN transistors and MMICs in Europe

2010 IEEE International Reliability Physics Symposium, 2010

ABSTRACT Recent DC- and RF-reliability results of European GaN HEMTs for high frequency power and... more ABSTRACT Recent DC- and RF-reliability results of European GaN HEMTs for high frequency power and MMIC applications between 2 and 18 GHz will be presented. The DC-stress test experiments have been performed at high current and high voltage settings in order to test the devices in the different regimes during large signal operation. GaN HEMTs and one stage MMICs have also been tested under RF-operation conditions and the correlation to DC-stress tests has been investigated.

Research paper thumbnail of Formation of deep traps at the 4H-SiC/SiO2 interface when utilizing sodium enhanced oxidation

Materials Science Forum, Aug 5, 2007

... semiconductor field effect transistors (MOSFETs) [1]. Sodium contained in the alumina materia... more ... semiconductor field effect transistors (MOSFETs) [1]. Sodium contained in the alumina material diffuses to the sample and enhances the oxidation rate, this in turn is suggested to be beneficial to interface quality [2]. When oxides are manufactured this way mobile charge in the ...

Research paper thumbnail of Formation of Deep Traps at the 4H-SiC/SiO<sub>2</sub> Interface when Utilizing Sodium Enhanced Oxidation

Materials Science Forum, 2007

Research paper thumbnail of High Field Effect Mobility in 6H-SiC MOSFET with Gate Oxides Grown in Alumina Environment

Materials Science Forum, 2005

... 25 (1996), p. 909 [4] S. Sridevan and BJ Baliga, Mater. Sci. Forum Vol. 264-268 (1998), p. 99... more ... 25 (1996), p. 909 [4] S. Sridevan and BJ Baliga, Mater. Sci. Forum Vol. 264-268 (1998), p. 997 [5] H.Ö Ólafsson, E.Ö. Sveinbjörnsson, TE Rudenko, IP Tyagulski, IN Osiyuk, and VS Lysenko, Appl. Phys. Lett. Vol. 79 (2001), p. 4034 ...

Research paper thumbnail of Field Effect Mobility in n-Channel Si Face 4H-SiC MOSFET with Gate Oxide Grown on Aluminium Ion-Implanted Material

Materials Science Forum, 2005

G. Gudjónsson1,a, H. Ö. Ólafsson1,b, F. Allerstam1,c, P.-Å. Nilsson1,d, E. Ö. Sveinbjörnsson1,e, ... more G. Gudjónsson1,a, H. Ö. Ólafsson1,b, F. Allerstam1,c, P.-Å. Nilsson1,d, E. Ö. Sveinbjörnsson1,e, T. Rödle2,f and R. Jos2,g ... 1Microwave Electronics Laboratory, Department of Microtechnology and Nanoscience, ... Chalmers University of Technology, Göteborg, ...

Research paper thumbnail of High Channel Mobility 4H-SiC MOSFETs

Materials Science Forum, 2006

Page 1. High channel mobility 4H-SiC MOSFETs E. Ö. Sveinbjörnsson 1,a , G. Gudjonsson 1,b , F. Al... more Page 1. High channel mobility 4H-SiC MOSFETs E. Ö. Sveinbjörnsson 1,a , G. Gudjonsson 1,b , F. Allerstam 1,c , H. Ö. Ólafsson 1,d , P-Å. Nilsson 1,e , H. Zirath 1,f , T. Rödle 2,g and R. Jos 2,h 1Microwave Electronics Laboratory ...

Research paper thumbnail of Long and Short Range Order in Ion Irradiated Ceramics Studied by IBA, EXAFS and Raman

Materials Science Forum, 1997

ABSTRACT

Research paper thumbnail of Sodium Enhanced Oxidation of Si-Face 4H-SiC: A Method to Remove Near Interface Traps

Materials Science Forum, 2007

... Catalysis A Vol. 184 (1999), p.127 [15] Z. Zheng, RE Tressler, KE Spear: Corrosion Science Vo... more ... Catalysis A Vol. 184 (1999), p.127 [15] Z. Zheng, RE Tressler, KE Spear: Corrosion Science Vol. 33 (1992), p. 545 [16] M. Riehl-Chuboda, S. Dupont, and P. Soukiassian: Surface Sci. Vol. 331-333 (1995), p. 625 [17] E. Opila: J. Am. Ceram. Soc. Vol. 78 (1995), p.1107 ...

Research paper thumbnail of High-efficiency, high-breakdown AlGaN/GaN HEMTs with lifetimes beyond 20 years

2008 Device Research Conference, 2008

AlGaN/GaN HEMTs on various substrates have raised a lot of interest for the application in future... more AlGaN/GaN HEMTs on various substrates have raised a lot of interest for the application in future high-efficiency base station systems for next generation mobile communication, currently dominated by LDMOS technology. Using GaN technology in a transmitter, infrastructure equipment manufacturers will benefit from major improvements in system performance and flexibility. AlGaN/GaN HEMTs enable innovative circuit concepts and transceiver architecture (e.g. switch

Research paper thumbnail of Design and realization of GaN RF-devices and circuits from 1 to 30 GHz

International Journal of Microwave and Wireless Technologies, 2010

The design, realization, and characterization of highly efficient powerbars and monolithic microw... more The design, realization, and characterization of highly efficient powerbars and monolithic microwave integrated circuit (MMIC) high-power amplifiers (HPAs) with AlGaN/GaN high electronic mobility transistors (HEMTs) are presented for the frequency range between 1 and 30 GHz. Packaged powerbars for the frequency range between 1 and 6 GHz have been developed based on a process called GaN50 with a gate length of 0.5 mm. Based on a GaN25 process with a gate length of 0.25 mm, high-power MMIC amplifiers are presented starting from 6 GHz up to advanced X-band amplifiers and robust LNAs in microstrip transmission line technology.

Research paper thumbnail of Comparison between oxidation processes used to obtain the high inversion channel mobility in 4H-SiC MOSFETs

Semiconductor Science and Technology, 2007

Page 1. Comparison between oxidation processes used to obtain the high inversion channel mobility... more Page 1. Comparison between oxidation processes used to obtain the high inversion channel mobility in 4H-SiC MOSFETs This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2007 Semicond. Sci. Technol. 22 307 ...

Research paper thumbnail of Development of AlGaN/GaN HEMTs with efficiencies above 60% up to 100 V for next generation mobile communication 100 W power bars

physica status solidi (c), 2009

ABSTRACT We present a systematic study of epitaxial growth, processing technology, device perform... more ABSTRACT We present a systematic study of epitaxial growth, processing technology, device performance and reliability of our GaN HEMTs manufactured on 3-inch SiC substrates. Epitaxy and processing are optimized for both performance and reliability. The deposition of the AlGaN/GaN HEMT epitaxial structures is designed for both low background carrier concentration and a low trap density in order to simultaneously achieve a high buffer isolation and low DC to RF dispersion. Device fabrication is performed using standard processing techniques involving both electron-beam and stepper lithography. The developed HEMTs demonstrate excellent high-voltage stability, high power performance and large power added efficiencies. Devices exhibit two-terminal gate-drain breakdown voltages in excess of 160 V (current criterion 1 mA/mm) across the entire 3-inch wafer with parasitic gate and drain currents well below 1 mA/mm when biased up to 80 V drain bias under pinch-off conditions. Load-Pull measurements at 2 GHz on 800 μm gate periphery devices return both a well-behaved relationship between bias-voltage and output-power as well as power-added-efficiencies beyond 60% up to UDS = 100 V. For a drain bias of 100 V an output-power-density around 22 W/mm with 26 dB linear gain is obtained. On large periphery devices (32 mm gate width packaged in industry-standard ceramic packages) an output power beyond 100 W is achieved with a PAE above 50% and a linear gain around 15 dB. Reliability is tested on devices having a gate periphery of 8×60 μm at an operating bias of 50 V under both DC and RF conditions. About 10% drain-current change under DC-stress (50 mA/mm) is observed after more than 1000 h of operation with an extrapolated drain-current degradation below 20% after 200,000 h (more than 20 years) of operation. Under RF stress (2 GHz, 1 dB compression) the observed change in output power density is below 0.2 dB after more than 1000 h. (© 2009 WILEY-VCH Verlag GmbH &amp; Co. KGaA, Weinheim)

Research paper thumbnail of Development of rugged 2 GHz power bars delivering more than 100 W and 60% power added efficiency

physica status solidi (c), 2010

Research paper thumbnail of Influence of the misorientation of 4H-SiC substrates on the morphology and crack formation in hetero epitaxial MOCVD grown GaN epilayers

physica status solidi (c), 2005

ABSTRACT

Research paper thumbnail of GaN HEMT and MMIC development at Fraunhofer IAF: performance and reliability

physica status solidi (a), 2009

ABSTRACT We present a systematic study of epitaxial growth, processing technology, device perform... more ABSTRACT We present a systematic study of epitaxial growth, processing technology, device performance and reliability of our GaN HEMTs and MMICs manufactured on 3 inch SiC substrates. Epitaxy and processing are optimized for both performance and reliability. The deposition of the AlGaN/GaN HEMT epitaxial structures is designed for low background carrier concentration and a low trap density in order to simultaneously achieve a high buffer isolation and low DC to RF dispersion. Device fabrication is performed using standard processing techniques involving both electron-beam and stepper lithography. Gate lengths of 250 nm and 500 nm are employed for 10 GHz and 2 GHz applications, respectively. The developed HEMTs demonstrate excellent high-voltage stability, high power performance and large power added efficiencies. Devices exhibit two-terminal gate–drain breakdown voltages in excess of 160 V (current criterion 1 mA/mm) across the entire 3 inch wafer with parasitic gate and drain currents well below 1 mA/mm when biased up to 80 V drain bias under pinch-off conditions. Load-Pull measurements at 2 GHz on 800 μm gate width devices return a well-behaved relationship between bias-voltage and output-power as well as power-added-efficiencies beyond 60% up to UDS = 100 V. For a drain bias of 100 V an output-power-density around 22 W/mm with 26 dB linear gain is obtained. On large devices (32 mm gate width packaged in industry-standard ceramic packages) an output power beyond 100 W is achieved with a PAE above 50% and a linear gain around 15 dB. Dual-stage MMICs in microstrip transmission line technology yield a power added efficiency of 40% at 8.56 GHz for a power level of 11 W. A single-stage MMIC yields a PAE of 46% with 7 W of output power at VDS = 28 V. Reliability is tested on HEMT devices having a gate periphery of 8 × 60 μm at an operating bias of 50 V under both DC and RF conditions. About 10% drain-current change under DC-stress (50 mA/mm) is observed after more than 1000 h of operation with an extrapolated drain-current degradation below 20% after 200000 h (more than 20 years) of operation. Under RF stress (2 GHz, 1 dB compression) the observed change in output power density is below 0.2 dB after more than 1000 h. (© 2009 WILEY-VCH Verlag GmbH &amp; Co. KGaA, Weinheim)

Research paper thumbnail of Reliability and degradation mechanism of AlGaAs/InGaAs and InAlAs/InGaAs HEMTs

physica status solidi (a), 2003

ABSTRACT The long-term stability of AlGaAs/GaAs and InAlAs/InGaAs high electron mobility transist... more ABSTRACT The long-term stability of AlGaAs/GaAs and InAlAs/InGaAs high electron mobility transistors (HEMTs), tested under high drain voltage and/or high temperature operation is reported. HEMTs with high In content in the active channel, alternatively fabricated on InP substrates and on GaAs substrates covered by a metamorphic buffer (MHEMT), are compared. Despite the high dislocation density in the buffer layer MHEMTs and InP based HEMTs exhibit comparable reliability. AlGaAs/GaAs HEMTs are more reliable than their InAlAs/InGaAs counterparts, especially when operated at high drain voltage. Failure mechanisms are thermally activated gate sinking, Ohmic contact degradation and hot electron induced degradation.

Research paper thumbnail of Qualification of 50V GaN on SiC technology for RF power amplifiers

Microelectronics Reliability, 2013

ABSTRACT This paper describes the qualification of the 50 V,0.5 mu m GaN on SiC process that has ... more ABSTRACT This paper describes the qualification of the 50 V,0.5 mu m GaN on SiC process that has been released at the III-V fab of UMS in Ulm in cooperation with IAF and NXP Semiconductors. The qualification at NXP is split into two parts: Part 1: investigation of die related wear-out failure mechanisms using a power device with 7.2 mm gate width and Part 2: final process release using the first product of NXP, a 50W wide band amplifier. The aim of the first part is to determine the acceleration factors for the major electric failure mechanism. These will be then used to define the qualification program of the wide band amplifier which will also include all package related tests. In this paper we will show how the tests are defined using the mission profile of the product. In addition, we will show the results. They are compared to results published in literature and are shown to be very promising.

Research paper thumbnail of Investigation of Leakage Current of AlGaN/GaN HEMTs Under Pinch-Off Condition by Electroluminescence Microscopy

Journal of Electronic Materials, 2010

... PLETSCHEN,1 WOLFGANG BRONNER,1 RU¨ DIGER QUAY,1 PATRICK WALTEREIT,1 MICHAEL MIKULLA,1 OLIVER ... more ... PLETSCHEN,1 WOLFGANG BRONNER,1 RU¨ DIGER QUAY,1 PATRICK WALTEREIT,1 MICHAEL MIKULLA,1 OLIVER AMBACHER,1 FRANCK BOURGEOIS,2 ... 1. A small band of enhanced EL intensity (ELI) and a bright spot were observed along the drain side of one of the ...

Research paper thumbnail of Design and Fabrication of 4H-SiC RF MOSFETs

IEEE Transactions on Electron Devices, 2000

ABSTRACT

Research paper thumbnail of Physics-Based Modeling of GaN HEMTs

IEEE Transactions on Electron Devices, 2000

A thorough approach to the investigation of GaNbased high-electron mobility transistors by device... more A thorough approach to the investigation of GaNbased high-electron mobility transistors by device simulation is demonstrated. Due to structure and material peculiarities, new comprehensive hydrodynamic models for the electron mobility are developed and calibrated. Relying on this setup, three different independent device technologies are simulated and compared. We further study the pronounced decrease in the transconductance g m at higher gate bias. We show that the electric field distribution and the resulting carrier velocity quasi-saturation are the main source for the transconductance collapse.

Research paper thumbnail of Reliability status of GaN transistors and MMICs in Europe

2010 IEEE International Reliability Physics Symposium, 2010

ABSTRACT Recent DC- and RF-reliability results of European GaN HEMTs for high frequency power and... more ABSTRACT Recent DC- and RF-reliability results of European GaN HEMTs for high frequency power and MMIC applications between 2 and 18 GHz will be presented. The DC-stress test experiments have been performed at high current and high voltage settings in order to test the devices in the different regimes during large signal operation. GaN HEMTs and one stage MMICs have also been tested under RF-operation conditions and the correlation to DC-stress tests has been investigated.

Research paper thumbnail of Formation of deep traps at the 4H-SiC/SiO2 interface when utilizing sodium enhanced oxidation

Materials Science Forum, Aug 5, 2007

... semiconductor field effect transistors (MOSFETs) [1]. Sodium contained in the alumina materia... more ... semiconductor field effect transistors (MOSFETs) [1]. Sodium contained in the alumina material diffuses to the sample and enhances the oxidation rate, this in turn is suggested to be beneficial to interface quality [2]. When oxides are manufactured this way mobile charge in the ...

Research paper thumbnail of Formation of Deep Traps at the 4H-SiC/SiO<sub>2</sub> Interface when Utilizing Sodium Enhanced Oxidation

Materials Science Forum, 2007

Research paper thumbnail of High Field Effect Mobility in 6H-SiC MOSFET with Gate Oxides Grown in Alumina Environment

Materials Science Forum, 2005

... 25 (1996), p. 909 [4] S. Sridevan and BJ Baliga, Mater. Sci. Forum Vol. 264-268 (1998), p. 99... more ... 25 (1996), p. 909 [4] S. Sridevan and BJ Baliga, Mater. Sci. Forum Vol. 264-268 (1998), p. 997 [5] H.Ö Ólafsson, E.Ö. Sveinbjörnsson, TE Rudenko, IP Tyagulski, IN Osiyuk, and VS Lysenko, Appl. Phys. Lett. Vol. 79 (2001), p. 4034 ...

Research paper thumbnail of Field Effect Mobility in n-Channel Si Face 4H-SiC MOSFET with Gate Oxide Grown on Aluminium Ion-Implanted Material

Materials Science Forum, 2005

G. Gudjónsson1,a, H. Ö. Ólafsson1,b, F. Allerstam1,c, P.-Å. Nilsson1,d, E. Ö. Sveinbjörnsson1,e, ... more G. Gudjónsson1,a, H. Ö. Ólafsson1,b, F. Allerstam1,c, P.-Å. Nilsson1,d, E. Ö. Sveinbjörnsson1,e, T. Rödle2,f and R. Jos2,g ... 1Microwave Electronics Laboratory, Department of Microtechnology and Nanoscience, ... Chalmers University of Technology, Göteborg, ...

Research paper thumbnail of High Channel Mobility 4H-SiC MOSFETs

Materials Science Forum, 2006

Page 1. High channel mobility 4H-SiC MOSFETs E. Ö. Sveinbjörnsson 1,a , G. Gudjonsson 1,b , F. Al... more Page 1. High channel mobility 4H-SiC MOSFETs E. Ö. Sveinbjörnsson 1,a , G. Gudjonsson 1,b , F. Allerstam 1,c , H. Ö. Ólafsson 1,d , P-Å. Nilsson 1,e , H. Zirath 1,f , T. Rödle 2,g and R. Jos 2,h 1Microwave Electronics Laboratory ...

Research paper thumbnail of Long and Short Range Order in Ion Irradiated Ceramics Studied by IBA, EXAFS and Raman

Materials Science Forum, 1997

ABSTRACT

Research paper thumbnail of Sodium Enhanced Oxidation of Si-Face 4H-SiC: A Method to Remove Near Interface Traps

Materials Science Forum, 2007

... Catalysis A Vol. 184 (1999), p.127 [15] Z. Zheng, RE Tressler, KE Spear: Corrosion Science Vo... more ... Catalysis A Vol. 184 (1999), p.127 [15] Z. Zheng, RE Tressler, KE Spear: Corrosion Science Vol. 33 (1992), p. 545 [16] M. Riehl-Chuboda, S. Dupont, and P. Soukiassian: Surface Sci. Vol. 331-333 (1995), p. 625 [17] E. Opila: J. Am. Ceram. Soc. Vol. 78 (1995), p.1107 ...

Research paper thumbnail of High-efficiency, high-breakdown AlGaN/GaN HEMTs with lifetimes beyond 20 years

2008 Device Research Conference, 2008

AlGaN/GaN HEMTs on various substrates have raised a lot of interest for the application in future... more AlGaN/GaN HEMTs on various substrates have raised a lot of interest for the application in future high-efficiency base station systems for next generation mobile communication, currently dominated by LDMOS technology. Using GaN technology in a transmitter, infrastructure equipment manufacturers will benefit from major improvements in system performance and flexibility. AlGaN/GaN HEMTs enable innovative circuit concepts and transceiver architecture (e.g. switch

Research paper thumbnail of Design and realization of GaN RF-devices and circuits from 1 to 30 GHz

International Journal of Microwave and Wireless Technologies, 2010

The design, realization, and characterization of highly efficient powerbars and monolithic microw... more The design, realization, and characterization of highly efficient powerbars and monolithic microwave integrated circuit (MMIC) high-power amplifiers (HPAs) with AlGaN/GaN high electronic mobility transistors (HEMTs) are presented for the frequency range between 1 and 30 GHz. Packaged powerbars for the frequency range between 1 and 6 GHz have been developed based on a process called GaN50 with a gate length of 0.5 mm. Based on a GaN25 process with a gate length of 0.25 mm, high-power MMIC amplifiers are presented starting from 6 GHz up to advanced X-band amplifiers and robust LNAs in microstrip transmission line technology.

Research paper thumbnail of Comparison between oxidation processes used to obtain the high inversion channel mobility in 4H-SiC MOSFETs

Semiconductor Science and Technology, 2007

Page 1. Comparison between oxidation processes used to obtain the high inversion channel mobility... more Page 1. Comparison between oxidation processes used to obtain the high inversion channel mobility in 4H-SiC MOSFETs This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2007 Semicond. Sci. Technol. 22 307 ...

Research paper thumbnail of Development of AlGaN/GaN HEMTs with efficiencies above 60% up to 100 V for next generation mobile communication 100 W power bars

physica status solidi (c), 2009

ABSTRACT We present a systematic study of epitaxial growth, processing technology, device perform... more ABSTRACT We present a systematic study of epitaxial growth, processing technology, device performance and reliability of our GaN HEMTs manufactured on 3-inch SiC substrates. Epitaxy and processing are optimized for both performance and reliability. The deposition of the AlGaN/GaN HEMT epitaxial structures is designed for both low background carrier concentration and a low trap density in order to simultaneously achieve a high buffer isolation and low DC to RF dispersion. Device fabrication is performed using standard processing techniques involving both electron-beam and stepper lithography. The developed HEMTs demonstrate excellent high-voltage stability, high power performance and large power added efficiencies. Devices exhibit two-terminal gate-drain breakdown voltages in excess of 160 V (current criterion 1 mA/mm) across the entire 3-inch wafer with parasitic gate and drain currents well below 1 mA/mm when biased up to 80 V drain bias under pinch-off conditions. Load-Pull measurements at 2 GHz on 800 μm gate periphery devices return both a well-behaved relationship between bias-voltage and output-power as well as power-added-efficiencies beyond 60% up to UDS = 100 V. For a drain bias of 100 V an output-power-density around 22 W/mm with 26 dB linear gain is obtained. On large periphery devices (32 mm gate width packaged in industry-standard ceramic packages) an output power beyond 100 W is achieved with a PAE above 50% and a linear gain around 15 dB. Reliability is tested on devices having a gate periphery of 8×60 μm at an operating bias of 50 V under both DC and RF conditions. About 10% drain-current change under DC-stress (50 mA/mm) is observed after more than 1000 h of operation with an extrapolated drain-current degradation below 20% after 200,000 h (more than 20 years) of operation. Under RF stress (2 GHz, 1 dB compression) the observed change in output power density is below 0.2 dB after more than 1000 h. (© 2009 WILEY-VCH Verlag GmbH &amp; Co. KGaA, Weinheim)

Research paper thumbnail of Development of rugged 2 GHz power bars delivering more than 100 W and 60% power added efficiency

physica status solidi (c), 2010

Research paper thumbnail of Influence of the misorientation of 4H-SiC substrates on the morphology and crack formation in hetero epitaxial MOCVD grown GaN epilayers

physica status solidi (c), 2005

ABSTRACT

Research paper thumbnail of GaN HEMT and MMIC development at Fraunhofer IAF: performance and reliability

physica status solidi (a), 2009

ABSTRACT We present a systematic study of epitaxial growth, processing technology, device perform... more ABSTRACT We present a systematic study of epitaxial growth, processing technology, device performance and reliability of our GaN HEMTs and MMICs manufactured on 3 inch SiC substrates. Epitaxy and processing are optimized for both performance and reliability. The deposition of the AlGaN/GaN HEMT epitaxial structures is designed for low background carrier concentration and a low trap density in order to simultaneously achieve a high buffer isolation and low DC to RF dispersion. Device fabrication is performed using standard processing techniques involving both electron-beam and stepper lithography. Gate lengths of 250 nm and 500 nm are employed for 10 GHz and 2 GHz applications, respectively. The developed HEMTs demonstrate excellent high-voltage stability, high power performance and large power added efficiencies. Devices exhibit two-terminal gate–drain breakdown voltages in excess of 160 V (current criterion 1 mA/mm) across the entire 3 inch wafer with parasitic gate and drain currents well below 1 mA/mm when biased up to 80 V drain bias under pinch-off conditions. Load-Pull measurements at 2 GHz on 800 μm gate width devices return a well-behaved relationship between bias-voltage and output-power as well as power-added-efficiencies beyond 60% up to UDS = 100 V. For a drain bias of 100 V an output-power-density around 22 W/mm with 26 dB linear gain is obtained. On large devices (32 mm gate width packaged in industry-standard ceramic packages) an output power beyond 100 W is achieved with a PAE above 50% and a linear gain around 15 dB. Dual-stage MMICs in microstrip transmission line technology yield a power added efficiency of 40% at 8.56 GHz for a power level of 11 W. A single-stage MMIC yields a PAE of 46% with 7 W of output power at VDS = 28 V. Reliability is tested on HEMT devices having a gate periphery of 8 × 60 μm at an operating bias of 50 V under both DC and RF conditions. About 10% drain-current change under DC-stress (50 mA/mm) is observed after more than 1000 h of operation with an extrapolated drain-current degradation below 20% after 200000 h (more than 20 years) of operation. Under RF stress (2 GHz, 1 dB compression) the observed change in output power density is below 0.2 dB after more than 1000 h. (© 2009 WILEY-VCH Verlag GmbH &amp; Co. KGaA, Weinheim)

Research paper thumbnail of Reliability and degradation mechanism of AlGaAs/InGaAs and InAlAs/InGaAs HEMTs

physica status solidi (a), 2003

ABSTRACT The long-term stability of AlGaAs/GaAs and InAlAs/InGaAs high electron mobility transist... more ABSTRACT The long-term stability of AlGaAs/GaAs and InAlAs/InGaAs high electron mobility transistors (HEMTs), tested under high drain voltage and/or high temperature operation is reported. HEMTs with high In content in the active channel, alternatively fabricated on InP substrates and on GaAs substrates covered by a metamorphic buffer (MHEMT), are compared. Despite the high dislocation density in the buffer layer MHEMTs and InP based HEMTs exhibit comparable reliability. AlGaAs/GaAs HEMTs are more reliable than their InAlAs/InGaAs counterparts, especially when operated at high drain voltage. Failure mechanisms are thermally activated gate sinking, Ohmic contact degradation and hot electron induced degradation.

Research paper thumbnail of Qualification of 50V GaN on SiC technology for RF power amplifiers

Microelectronics Reliability, 2013

ABSTRACT This paper describes the qualification of the 50 V,0.5 mu m GaN on SiC process that has ... more ABSTRACT This paper describes the qualification of the 50 V,0.5 mu m GaN on SiC process that has been released at the III-V fab of UMS in Ulm in cooperation with IAF and NXP Semiconductors. The qualification at NXP is split into two parts: Part 1: investigation of die related wear-out failure mechanisms using a power device with 7.2 mm gate width and Part 2: final process release using the first product of NXP, a 50W wide band amplifier. The aim of the first part is to determine the acceleration factors for the major electric failure mechanism. These will be then used to define the qualification program of the wide band amplifier which will also include all package related tests. In this paper we will show how the tests are defined using the mission profile of the product. In addition, we will show the results. They are compared to results published in literature and are shown to be very promising.

Research paper thumbnail of Investigation of Leakage Current of AlGaN/GaN HEMTs Under Pinch-Off Condition by Electroluminescence Microscopy

Journal of Electronic Materials, 2010

... PLETSCHEN,1 WOLFGANG BRONNER,1 RU¨ DIGER QUAY,1 PATRICK WALTEREIT,1 MICHAEL MIKULLA,1 OLIVER ... more ... PLETSCHEN,1 WOLFGANG BRONNER,1 RU¨ DIGER QUAY,1 PATRICK WALTEREIT,1 MICHAEL MIKULLA,1 OLIVER AMBACHER,1 FRANCK BOURGEOIS,2 ... 1. A small band of enhanced EL intensity (ELI) and a bright spot were observed along the drain side of one of the ...

Research paper thumbnail of Design and Fabrication of 4H-SiC RF MOSFETs

IEEE Transactions on Electron Devices, 2000

ABSTRACT

Research paper thumbnail of Physics-Based Modeling of GaN HEMTs

IEEE Transactions on Electron Devices, 2000

A thorough approach to the investigation of GaNbased high-electron mobility transistors by device... more A thorough approach to the investigation of GaNbased high-electron mobility transistors by device simulation is demonstrated. Due to structure and material peculiarities, new comprehensive hydrodynamic models for the electron mobility are developed and calibrated. Relying on this setup, three different independent device technologies are simulated and compared. We further study the pronounced decrease in the transconductance g m at higher gate bias. We show that the electric field distribution and the resulting carrier velocity quasi-saturation are the main source for the transconductance collapse.