Dammann, M., Pletschen, W., Waltereit, P., Bronner, W., Quay, R., Müller, S., ...
Excellent reliability performance of AlGaN/GaN HEMTs on SiC substrates for next generation mobile communication systems has been demonstrated using DC and RF stress tests on 8 x 60 µm wide and 0.5...
GaN HEMT and MMIC development at Fraunhofer IAF: Performance and reliability (2009)
Waltereit, P., Bronner, W., Quay, R., Dammann, M., Kiefer, R., Müller, S., ...
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...
Waltereit, P., Müller, S., Bellmann, K., Buchheim, C., Goldhahn, R., Köhler, K., ...
We systematically investigate Al(0.22)Ga(0.78)N/GaN high electron mobility transistors with GaN cap layer thicknesses of 0, 1, and 3 nm. All samples have electron mobilities around 1700 cm2/Vs and...
Waltereit, P., Bronner, W., Quay, R., Dammann, M., Müller, S., Musser, M., ...
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...
Gallium nitride MMICs for future reconnaissance and imaging applications (2009)
Quay, R., Mikulla, M., Waltereit, P., Van Raay, F., Dammann, M., Kühn, J., ...
For next generation active electronically scanned array (AESA) radars, Gallium Nitride (GaN) monolithic microwave integrated circuit (MMIC) power amplifiers, combined with advanced circuit and module...
Growth and electrical properties of AlxGa1-xN/GaN heterostructures with different Al-content (2009)
Köhler, K., Müller, S., Waltereit, P., Kirste, L., Menner, H., Bronner, W., ...
High electron mobility transistor material and device properties based on AlxGa1-xN/GaN heterostructures with an Al-content ranging from 12 to 35% are presented. The Al-content of the low pressure...
L-to-Ka-band AlGaN/GaN HEMT power amplifiers with high efficiency (2009)
Quay, R., Van Raay, F., Kühn, J., Kiefer, R., Waltereit, P., Musser, M., ...
This paper describes highly-efficient GaN/AlGaN HEMT and MMIC power amplifiers for RF-frequencies between 0.5 GHz and 30 GHz fabricated on three-inch s.i. SiC substrates. Three GaN HEMT technologies...
Plasma assisted molecular beam epitaxy of AlGaN/GaN high electron mobility transistors (2008)
Aidam, R., Kirste, L., Kunzer, M., Müller, S., Waltereit, P.
We report on the plasma-assisted molecular beam epitaxy (PAMBE) of AlGaN/GaN high electron mobility transistors (HEMTS). Growth was performed on MOCVD grown GaN Templates and 4H-SiC(0001) wafers with...
High-efficiency GaN HEMTs on 3-inch semi-insulating SiC substrates (2008)
Waltereit, P., Bronner, W., Quay, R., Dammann, M., Müller, S., Kiefer, R., ...
We report on device performance and reliability of our 3" GaN high electron mobility transistor (HEMT) technology. AlGaN/GaN HEMT structures are grown on semi-insulating SiC substrates by...
Efficient AlGaN/GaN HEMT power amplifiers (2008)
Quay, R., Van Raay, F., Kühn, J., Kiefer, R., Waltereit, P., Zorcic, M., ...
This paper describes efficient GaN/AlGaN HEMTs and MMICs for L/S-band (1-4 GHz) and X-band frequencies (8-12 GHz) on three-inch s.i. SiC substrates. Dual-stage MMICs in microstrip transmission-line...
Dammann, M., Pletschen, W., Waltereit, P., Bronner, W., Quay, R., Müller, S., ...
Excellent reliability performance of AlGaN/GaN HEMTs on SiC substrates for next generation mobile communication systems has been demonstrated using DC and RF stress tests on 8x60 µm wide and 0.5 µm...
Waltereit, P., Bronner, W., Quay, R., Dammann, M., Müller, S., Kiefer, R., ...
We report on device performance and reliability of our 3" GaN HEMT technology. AlGaN/GaN HEMT structures are grown on semi-insulating SiC substrates by MOCVD with sheet resistance uniformities better...
Role of inclined threading dislocations in stress relaxation in mismatched layers (2005)
Cantu, P, Wu, F, Waltereit, P, Keller, S, Romanov, A E, DenBaars, S P, ...
(0001)-oriented epitaxial wurtzite III-nitride layers grown on mismatched substrates have no resolved shear stress on the natural basal and prismatic slip planes; however, strained Ill-nitride layers...
Buried stressors in nitride semiconductors: Influence on electronic properties (2005)
Romanov, A E, Waltereit, P, Speck, J S
An analysis is presented on the effect of the strain field originating from a subsurface stressor (point source of dilatation or a dilatating ellipsoidal inclusion) on the electronic properties of...
Power performance of AlGaN-GaNHEMTs grown on SiC by plasma-assisted MBE (2004)
Rajan, Siddharth, Waltereit, P, Poblenz, C, Heikman, S J, Green, D S, Speck, J S, ...
We report AlGaN-GaN high electron mobility transistors (HEMTs) grown by molecular beam epitaxy (MBE) on SiC substrates with excellent microwave power and efficiency performance. The GaN buffers in...
Miller, E J, Schaadt, D M, Yu, E T, Sun, X L, Brillson, L J, Waltereit, P, ...
Dislocation-related conduction paths in n-type GaN grown by molecular-beam epitaxy and a mechanism for local suppression of current flow along these paths are analyzed using conductive atomic force...
Simpkins, B S, Yu, E T, Waltereit, P, Speck, J S
Scanning Kelvin probe microscopy (SKPM) and conductive atomic force microscopy (C-AFM) have been used to image surfaces of GaN grown by molecular beam epitaxy. Detailed analysis of the same area...
Brandt, O, Sun, Y J, Schonherr, H P, Ploog, K H, Waltereit, P, Lim, S H, ...
We present a simple strategy that minimizes the impact of surface segregation of In during the growth of (In,Ga) N/GaN multiple quantum wells by plasma-assisted molecular-beam epitaxy and...
Si doping effect on strain reduction in compressively strained Al0.49Ga0.51N thin films (2003)
Cantu, P, Wu, F, Waltereit, P, Keller, S, Romanov, A E, Mishra, U K, ...
Evaluation of the structural properties of 200-nm-thick Si-doped Al0.49Ga0.51N films, grown on nominally relaxed 1-mum-thick Al0.62Ga0.38N buffer layers on sapphire, revealed that increased Si doping...
Keller, S, Waltereit, P, Cantu, P, Mishra, U K, Speck, J S, DenBaars, S P
280 nm thick Al0.2Ga0.8N/Al0.7Ga0.3N superlattice structures with various well and barrier layer thickness and different silicon doping were grown on 1.2 mum thick Al0.63Ga0.37N-on-sapphire films by...
Miller, E J, Schaadt, D M, Yu, E T, Waltereit, P, Poblenz, C, Speck, J S
An electrochemical surface treatment has been developed that decreases the reverse-bias leakage current in Schottky diodes fabricated on GaN grown by molecular-beam epitaxy (MBE). This treatment...
Sun, Y J, Brandt, O, Cronenberg, S, Dhar, S, Grahn, H T, Ploog, K H, ...
M-plane In0.1Ga0.9N(1 (1) over bar 00) multiple quantum wells were grown on gamma-LiAlO2(100) by plasma-assisted molecular-beam epitaxy. The high brightness of the photoluminescence of these multiple...
Jahn, U., Dahr, S., Waltereit, P., Kostial, H., Watson, I.M. *, Fujiwara, K
The electronic properties of (In,Ga)N/GaN quantum wells depend significantly on the exposure dose of low-energy electron-beam irradiation (LEEBI), which is used, e.g. for cathodoluminescence (CL)....
Jahn, U., Dahr, S., Waltereit, P., Kostial, H., Watson, I.M., Fujiwara, K.
The electronic properties of (In,Ga)N/GaN quantum wells depend significantly on the exposure dose of low-energy electron-beam irradiation (LEEBI), which is used, e.g. for cathodoluminescence (CL)....
Jahn, U., Dahr, S., Waltereit, P., Kostial, H., Watson, I.M., Fujiwara, K.
The electronic properties of (In,Ga)N/GaN quantum wells depend significantly on the exposure dose of low-energy electron-beam irradiation (LEEBI), which is used, e.g. for cathodoluminescence (CL)....
Giehler, M., Ramsteiner, M., Waltereit, P., Brandt, O., Ploog, K.H., Obloh, H.
We study the influence of heteroepitaxy as well as intrinsic anharmonicity of the E2(high) and A1(LO) lattice vibrations in wurtzite GaN layers. The intrinsic phononSphonon scattering of bulk GaN...