High-frequency enhancement-mode millimeterwave AlGaN/GaN HEMT with an fT/fmax over 100 GHz/200 GHz  

作　　者：Sheng Wu Minhan Mi Xiaohua Ma Ling Yang Bin Hou Yue Hao 武盛;宓珉瀚;马晓华;杨凌;侯斌;郝跃(Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices,School of Microelectronics,Xidian University,Xi'an 710071,China)

机构地区：[1]Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices,School of Microelectronics,Xidian University,Xi'an 710071,China

出　　处：《Chinese Physics B》2021年第8期444-448,共5页中国物理B（英文版）

基　　金：Project supported by the National Key Research and Development Program of China(Grant No.2020YFB1804902);the National Natural Science Foundation of China(Grant No.61904135);the China Postdoctoral Science Foundation(Grant Nos.2018M640957 and BX20200262);the Natural Science Foundation of Shaanxi Province,China(Grant No.2020JQ-316).

摘　　要：Ultra-thin barrier(UTB) 4-nm-Al Ga N/Ga N normally-off high electron mobility transistors(HEMTs) having a high current gain cut-off frequency( fT) are demonstrated by the stress-engineered compressive Si N trench technology.The compressive in-situ Si N guarantees the UTB-Al Ga N/Ga N heterostructure can operate a high electron density of1.27×1013 cm-2, a high uniform sheet resistance of 312.8 Ω/, but a negative threshold for the short-gate devices fabricated on it. With the lateral stress-engineering by full removing in-situ Si N in the 600-nm Si N trench, the short-gated(70 nm) devices obtain a threshold of 0.2 V, achieving the devices operating at enhancement-mode(E-mode). Meanwhile,the novel device also can operate a large current of 610 m A/mm and a high transconductance of 394 m S/mm for the Emode devices. Most of all, a high fT/fmax of 128 GHz/255 GHz is obtained, which is the highest value among the reported E-mode Al Ga N/Ga N HEMTs. Besides, being together with the 211 GHz/346 GHz of fT/fmax for the D-mode HEMTs fabricated on the same materials, this design of E/D-mode with the realization of fmax over 200 GHz in this work is the first one that can be used in Q-band mixed-signal application with further optimization. And the minimized processing difference between the E-and D-mode designs the addition of the Si N trench, will promise an enormous competitive advantage in the fabricating costs.

关 键 词：ultra-thin barrier(UTB) AlGaN/GaN in-situ SiN stress-engineering ENHANCEMENT-MODE mixed-signal applications 

分 类 号：TN386[电子电信—物理电子学]