2D Device Simulation of AlGaN/GaN HFET Current Collapse Caused by Deep Levels in GaN Buffer Layer

2011 ◽  
Author(s):  
Y. Ikawa ◽  
T. Hosokawa ◽  
Y. Kio ◽  
J. P. Ao ◽  
Y. Ohno
Keyword(s):  
Buffer Layer ◽  
Device Simulation ◽  
Deep Levels ◽  
Current Collapse ◽  
Gan Hfet ◽  
Gan Buffer Layer

Effect of multiple carbon-doped/undoped GaN buffer layer on current collapse in AlGaN/GaN HEMTs

2013 ◽  
Author(s):  
H.S. Kang ◽  
C.H. Won ◽  
D.S. Kim ◽  
S.M. Jeon ◽  
Y.J. Kim ◽  
...  
Keyword(s):  
Buffer Layer ◽  
Carbon Doped ◽  
Current Collapse ◽  
Gan Hemts ◽  
Gan Buffer Layer

scholarly journals Influence of pit defects on AlGaN surface and dislocation defects in GaN buffer layer on current collapse of AlGaN/GaN HEMTs

2008 ◽  
Vol 57 (11) ◽  
pp. 7238
Author(s):  
Xi Guang-Yi ◽  
Ren Fan ◽  
Hao Zhi-Biao ◽  
Wang Lai ◽  
Li Hong-Tao ◽  
...  
Keyword(s):  
Buffer Layer ◽  
Current Collapse ◽  
Gan Hemts ◽  
Dislocation Defects ◽  
Gan Buffer Layer

INFLUENCE OF POLARIZATION CHARGES AND ELECTRON TRAPPING IN THE BUFFER LAYER IN WURTZITE PHASE AlGaN/GaN HFETs

2006 ◽  
Vol 20 (22) ◽  
pp. 1397-1404 ◽  
Author(s):  
H. ARABSHAHI ◽  
M. H. GHASEMIAN
Keyword(s):  
Monte Carlo ◽  
Electron Transport ◽  
Buffer Layer ◽  
Interface Layer ◽  
Electron Trapping ◽  
Wurtzite Phase ◽  
Polarization Effects ◽  
Ensemble Monte Carlo ◽  
Current Collapse ◽  
Gan Hfet

Ensemble Monte Carlo simulations have been performed to model electron transport in wurtzite phase AlGaN/GaN heterojunction FETs. Planar Al 0.2 Ga 0.8 N/GaN HFET structures with a 78 nm Al 0.2 Ga 0.8 N pseudomorphically strained layer were simulated, where the spontaneous and piezoelectric polarization effects were taken into account. Trap centers located in the buffer layer has also been simulated to include the effect of trapping levels on current collapse in GaN HFETs. The polarization effects was shown to not only increase the current density, but also improve the electron transport in the interface layer by inducing a higher electron density to the positive polarized sheet and away from the buffer layer.

2D Device Simulation of AlGaN/GaN HFET Current Collapse Caused by Surface Negative Charge Injection

2010 ◽  
Vol E93-C (8) ◽  
pp. 1218-1224 ◽  
Author(s):  
Yusuke IKAWA ◽  
Yorihide YUASA ◽  
Cheng-Yu HU ◽  
Jin-Ping AO ◽  
Yasuo OHNO
Keyword(s):  
Negative Charge ◽  
Device Simulation ◽  
Charge Injection ◽  
Current Collapse ◽  
Gan Hfet

Impact of Multi-Layer Carbon-Doped/Undoped GaN Buffer on Suppression of Current Collapse in AlGaN/GaN HFETs

2014 ◽  
Vol 23 (03n04) ◽  
pp. 1450017 ◽  
Author(s):  
Hee-Sung Kang ◽  
Dong-Seok Kim ◽  
Chul-Ho Won ◽  
Young-Jo Kim ◽  
Young Jun Yoon ◽  
...  
Keyword(s):  
Buffer Layer ◽  
Field Effect Transistors ◽  
Total Carbon ◽  
Structural Quality ◽  
Deep Acceptor ◽  
Carbon Doped ◽  
Current Collapse ◽  
Possible Cause ◽  
Gan Buffer Layer ◽  
Buffer Structure

We present a new semi-insulating GaN buffer layer, which consists of multiple carbon-doped and undoped GaN layers, suitable for AlGaN / AlN / GaN heterojunction field effect transistors. The proposed buffer structure was designed to minimize the total carbon incorporation into the buffer layer because carbon atoms in GaN are a possible cause of deterioration in structural quality and device characteristics such as current collapse. With this new buffer structure, current collapse in GaN MISHFET is drastically reduced while maintaining high breakdown characteristics. We argue that electron transfer from the undoped GaN to the carbon-doped GaN layer leads to total depletion of the undoped GaN layer and effectively compensates the deep-acceptor states in the carbon-doped GaN layer. This mechanism results in high-insulating buffer characteristic and opens the avenue for current collapse suppression in AlGaN / AlN / GaN MISHFET.

The Influence of Growth Temperature on Oxygen Concentration in GaN Buffer Layer

2008 ◽  
Vol 1068 ◽  
Author(s):  
Ewa Dumiszewska ◽  
Wlodek Strupinski ◽  
Piotr Caban ◽  
Marek Wesolowski ◽  
Dariusz Lenkiewicz ◽  
...  
Keyword(s):  
High Temperature ◽  
Buffer Layer ◽  
Oxygen Concentration ◽  
Growth Temperature ◽  
Low Temperatures ◽  
Buffer Layers ◽  
Crystalline Quality ◽  
Temperature Growth ◽  
Gan Buffer Layer

ABSTRACTThe influence of growth temperature on oxygen incorporation into GaN epitaxial layers was studied. GaN layers deposited at low temperatures were characterized by much higher oxygen concentration than those deposited at high temperature typically used for epitaxial growth. GaN buffer layers (HT GaN) about 1 μm thick were deposited on GaN nucleation layers (NL) with various thicknesses. The influence of NL thickness on crystalline quality and oxygen concentration of HT GaN layers were studied using RBS and SIMS. With increasing thickness of NL the crystalline quality of GaN buffer layers deteriorates and the oxygen concentration increases. It was observed that oxygen atoms incorporated at low temperature in NL diffuse into GaN buffer layer during high temperature growth as a consequence GaN NL is the source for unintentional oxygen doping.

On/off-state noise characteristics in AlGaN/GaN HFET with AlN buffer layer

2022 ◽  
Vol 120 (1) ◽  
pp. 012102
Author(s):  
Ki-Sik Im ◽  
Uiho Choi ◽  
Minho Kim ◽  
Jinseok Choi ◽  
Hyun-Seop Kim ◽  
...  
Keyword(s):  
Buffer Layer ◽  
Noise Characteristics ◽  
Gan Hfet ◽  
Aln Buffer

Effect of N/Ga Flux Ratio in GaN Buffer Layer Growth by MBE on (0001) Sapphire on Defect Formation in the GaN Main Layer

1999 ◽  
Vol 572 ◽  
Author(s):  
S. Ruvimov ◽  
Z. Liliental-Weber ◽  
J. Washburn ◽  
Y. Kim ◽  
G. S. Sudhir ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Buffer Layer ◽  
Defect Formation ◽  
Flux Ratio ◽  
Growth Conditions ◽  
Buffer Layers ◽  
Simultaneous Increase ◽  
Growth Stages ◽  
Dislocation Generation ◽  
Gan Buffer Layer

ABSTRACTTransmission electron microscopy was employed to study the effect of N/Ga flux ratio in the growth of GaN buffer layers on the structure of GaN epitaxial layers grown by molecular-beamepitaxy (MBE) on sapphire. The dislocation density in GaN layers was found to increase from 1×1010 to 6×1010 cm−2 with increase of the nitrogen flux from 5 to 35 sccm during the growth of the GaN buffer layer with otherwise the same growth conditions. All GaN layers were found to contain inversion domain boundaries (IDBs) originated at the interface with sapphire and propagated up to the layer surface. Formation of IDBs was often associated with specific defects at the interface with the substrate. Dislocation generation and annihilation were shown to be mainly growth-related processes and, hence, can be controlled by the growth conditions, especially during the first growth stages. The decrease of electron Hall mobility and the simultaneous increase of the intensity of “green” luminescence with increasing dislocation density suggest that dislocation-related deep levels are created in the bandgap.

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