Open AccessHigh‐frequency AlGaN/GaN HFETs with f T / f max of 149/263 GHz for D‐band PA applications
Author(s) -
Lv Yuanjie,
Song Xubo,
Guo Hongyu,
Fang Yulong,
Feng Zhihong
Publication year - 2016
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
ISSN - 1350-911X
DOI - 10.1049/el.2016.1241
Subject(s) - materials science , transconductance , ohmic contact , optoelectronics , transistor , amplifier , gallium nitride , oscillation (cell signaling) , high electron mobility transistor , cutoff frequency , wide bandgap semiconductor , heterojunction , substrate (aquarium) , electrical engineering , voltage , nanotechnology , layer (electronics) , oceanography , cmos , biology , geology , genetics , engineering
Scaled AlGaN/GaN heterostructure field‐effect transistors (HFETs) with high unity current gain cut‐off frequency ( f T ) and maximum oscillation frequency (f max ) were fabricated and characterised on SiC substrate. In the device, scaled source‐to‐drain distance ( L sd ) of 600 nm was realised by employing non‐alloyed regrown n + ‐GaN ohmic contacts. A 60 nm T‐shaped AlGaN/GaN HFETs showed excellent DC and RF performance after gate recess. A record extrinsic transconductance ( g m ) of 764 mS/mm was obtained in the AlGaN/GaN HFETs. Moreover, the maximum f T and f max of the fabricated device reach to 149 and 263 GHz at the same bias, exhibiting a record‐high value of f T * f max . This indicates that the AlGaN/GaN HFETs still have the potential for D‐band (110–170 GHz) power‐amplifier application with further optimisation.