Influence of Fin-Like Configuration Parameters on the Linearity of AlGaN/GaN HEMTs
Pengfei Wang, Xiaohua Ma, Minhan Mi, Meng Zhang, Jiejie Zhu, Yuwei Zhou, Sheng Wu, Jielong Liu, Ling Yang, Bin Hou, Yue Hao
Abstract
In this letter, we explore the impact of configuration parameters for Fin-like high-electron-mobility transistors (HEMTs) formed by partially etching barrier under the gate on improving transconductance (Gm) and cutoff frequency ( f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</sub> ) linearity. It is found that the Gm profile for Fin-like HEMTs can be optimized by choosing appropriate device parameters, including the etching depth ( H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R</sub> ) and width ( W <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R</sub> ) of recess region, as well as the duty ratio ( α) of the planar elements in a periodic unit along the gate width. In general, not only does W <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R</sub> affect the gate voltage swing (GVS) but also H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R</sub> and α have an important role in Gm profile flatness. In addition, the fabricated Fin-like HEMTs shows a GVS of the transconductance plateau larger than 5.6 V and a constant f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</sub> /f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> of 45 GHz/65 GHz over a wide gate voltage range. Furthermore, the proposed architecture also features an exceptional linearity performance at 8 GHz with an output third-order intercept point (OIP3) of 38.5 dBm, whereas that of the planar HEMT is 31 dBm. The device demonstrated in this article has great potential to be a new paradigm for future wireless communication systems where high linearity is essential.