Open AccessComparative Studies of AlGaAs/InGaAs Enhancement/Depletion-Mode High Electron Mobility Transistors with Virtual Channel Layers by Hybrid Gate Recesses Approaches -=SUP=-*-=/SUP=-
Author(s) -
JungHui Tsai,
Pao-Sheng Lin,
YuChi Chen,
Syuan-Hao Liou,
Jing-Shiuan Niu
Publication year - 2019
Publication title -
fizika i tehnika poluprovodnikov
Language(s) - English
Resource type - Journals
eISSN - 1726-7315
pISSN - 0015-3222
DOI - 10.21883/ftp.2019.03.47299.8848
Subject(s) - transistor , materials science , optoelectronics , virtual channel , electron mobility , channel (broadcasting) , and gate , threshold voltage , voltage , electrical engineering , engineering
Unlike the conventional GaAs- and InP-based enhancement/depletion-mode ( E / D -mode) transistors, the improved gate characteristics of the AlGaAs/InGaAs E -mode high electron mobility transistors (HEMTs) by way of hybrid gate recesses to remove the n -AlAs/ i -GaAs/ n -AlGaAs virtual channel layers upon 2DEG channels are demonstrated. As compared to the D -mode device (sample A), the gate reverse currents are effectively reduced by 45 and 102 times for the E -mode devices with additional gate recess time of 24 s (sample B) and 30 s (sample C) to remove part of the virtual channel layers, respectively. Under gate forward bias, the hybrid gate recesses also enable the gate turn-on voltages to increase. Furthermore, the threshold voltages of –1.25, 0.09, and 0.22 V are observed in the samples A, B, and C, respectively. The maximum transconductances of 187.3, 209.2, and 243.4 mS/mm and saturation current density of 482.8, 410.6, and 347.4 mA/mm are obtained in the samples A, B, and C, respectively.