Surface barrier height for different Al compositions and barrier layer thicknesses in AlGaN/GaN heterostructure field effect transistors

2013 ◽  
Author(s):  
Nitin Goyal ◽  
Benjamin Iniguez ◽  
Tor A. Fjeldly
Keyword(s):  
Barrier Height ◽  
Barrier Layer ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Surface Barrier ◽  
Heterostructure Field Effect Transistors ◽  
Gan Heterostructure

AlGaN/GaN Heterostructure Field-Effect Transistors with Back-Doping Design for High-Power Applications: High Current Density with High Transconductance Characteristics

2002 ◽  
Vol 743 ◽  
Author(s):  
Narihiko Maeda ◽  
Kotaro Tsubaki ◽  
Tadashi Saitoh ◽  
Takehiko Tawara ◽  
Naoki Kobayashi
Keyword(s):  
Barrier Layer ◽  
Field Effect ◽  
Field Effect Transistors ◽  
High Current Density ◽  
High Current ◽  
Algan Barrier ◽  
Heterostructure Field Effect Transistors ◽  
Algan Barrier Layer ◽  
Gan Heterostructure ◽  
High Transconductance

ABSTRACTElectron transport properties and DC device characteristics have been examined in the AlGaN/GaN heterostructure field-effect transistors (HFETs) with back-doping design that makes it possible to obtain high two-dimensional electron gas (2DEG) densities even for the devices with thin AlGaN barrier layers. In the back-doping design, an asymmetric double-heterostructure is employed, and donor atoms are doped not only in the surface-side AlGaN layer but also in the underlying AlGaN layer. In this structure, electrons are efficiently supplied also from the back-doped AlGaN barrier layer to the GaN channel and merged into a single 2DEG layer, with the help of the negative polarization charges at the heterointerface between the GaN channel and the underlying AlGaN barrier layer. By using back-doping design, very high 2DEG densities around 3×1013 cm−2 has been achieved in the Al0.3Ga0.7N/GaN HFET whose barrier layer (Al0.3Ga0.7N) is designed to be as thin as 120 Å. An HFET with the gate-length of 1.5 μm has exhibited a high current density of 1.2 A/mm and a high transconductance of 200 mS/mm, which is ascribed to high 2DEG densities and thin barrier layers in these devices. HFETs with the back-doping design are thus promising for high-power applications.

Back-Doping Design in AlGaN/GaN Heterostructure Field-Effect Transistors for High-Power Applications

2001 ◽  
Vol 693 ◽  
Author(s):  
Narihiko Maeda ◽  
Kotaro Tsubaki ◽  
Tadashi Saitoh ◽  
Naoki Kobayashi
Keyword(s):  
Barrier Layer ◽  
High Power ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Algan Layer ◽  
Barrier Layers ◽  
Algan Barrier ◽  
Heterostructure Field Effect Transistors ◽  
Algan Barrier Layer ◽  
Gan Heterostructure

AbstractA novel doping design has been proposed that yields high two-dimensional electron gas (2DEG) densities in the AlGaN/GaN heterostructure field-effect transistors (HFETs) even when the AlGaN barrier layers are designed to be very thin. In the novel doping design, an asymmetric double-heterostructure is employed, and donor atoms are doped not only in the surface-side AlGaN layer but also in the underlying AlGaN layer. In this structure, electrons are efficiently supplied also from the back-doped AlGaN barrier layer to the GaN channel, with the help of the negative polarization charges at the heterointerface between the GaN channel and the underlying AlGaN barrier layer. High 2DEG densities can thus be obtained. Moreover, relatively high 2DEG mobilities can be obtained for high 2DEG densities, because back-doped donor atoms are sufficiently remote from the position of the 2DEG so that the 2DEG is less subjected to the ionized impurity scattering due to the relevant donor atoms. By using this back-doping design, a very high 2DEG density of 2.8x1013 cm-2 (2DEG mobility is 850 cm2/Vs) has been obtained at 300 K in the Al0.3Ga0.7N/GaN HFET whose barrier layer (Al0.3Ga0.7N) is as thin as 120 Å. Thus, the back-doping design is effective to obtain high 2DEG densities in the HFETs with thin barrier layers, and promising for high-power applications.

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