High transconductance heterostructure field‐effect transistors based on AlGaN/GaN

1996 ◽  
Vol 69 (6) ◽  
pp. 794-796 ◽  
Author(s):  
Q. Chen ◽  
M. Asif  Khan ◽  
J. W. Yang ◽  
C. J. Sun ◽  
M. S. Shur ◽  
...  
Keyword(s):  
Field Effect ◽  
Field Effect Transistors ◽  
Heterostructure Field Effect Transistors ◽  
High Transconductance

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.

Dc and Microwave Characteristics of High Transconductance AlGaN/GaN Heterostructure Field Effect Transistors on Sic Substrates

1997 ◽  
Vol 482 ◽  
Author(s):  
Q. Chen ◽  
J. W. Yang ◽  
M. A. Khan ◽  
A. T. Ping ◽  
I. Adesida
Keyword(s):  
Field Effect ◽  
Field Effect Transistors ◽  
Cutoff Frequency ◽  
Channel Current ◽  
Heterostructure Field Effect Transistors ◽  
High Power Operation ◽  
Drain Bias ◽  
Gan Heterostructure ◽  
High Transconductance ◽  
P Type

AbstractHigh quality AJGaN/GaN heterostructures have been successfully deposited on both nand p-type SiC substrates. Heterostructure field effect transistors fabricated using these layers exhibited high channel current density (1.71 A/mm), well behaved pinch-off characteristics, and excellent extrinsic transconductance (Gm = 229 mS/mm). There is negligible channel current degradation up to a source to drain bias of 20 V as opposed to devices grown on sapphire substrates. The 0.25 μm gate-length devices fabricated on the heterostructures grown on p-type SiC has allowed us to extract a cutoff frequency of 53 GHz. The cutoff frequency showed little deterioration with increasing drain bias voltage. These results demonstrate for the first time the high frequency and high power operation potential of the heterostructure field effect transistors based on AlGaN grown on SiC.

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