Open AccessHigh RF performance improvement using surface passivation technique of AlGaN/GaN HEMTs at K‐band application
Author(s) -
Lee B.H.,
Kim R.H.,
Lim B.O.,
Choi G.W.,
Kim H.J.,
Hong I.P.,
Lee J.H.
Publication year - 2013
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.2013.1211
Subject(s) - passivation , transconductance , materials science , high electron mobility transistor , optoelectronics , ohmic contact , transistor , gallium nitride , wide bandgap semiconductor , layer (electronics) , electrical engineering , nanotechnology , engineering , voltage
A surface passivation technique of high electron mobility transistor (HEMT) devices is reported. The passivated HEMT device has a much higher RF performance of F T and F max than a non‐passivated one. The AlGaN/GaN HEMT has a short gate length of 0.15 µm using an E‐beam lithography system and very low ohmic contact resistance of 1.3 × 10 −6 Ωcm −2 using a rapid thermal processing alloy system. In addition, to protect the active layer from the surface trap, an SiO 2 thin film passivation process is applied by the plasma‐enhanced chemical vapour deposition system. The fabricated AlGaN/GaN HEMT exhibits a maximum drain current of 900 mA/mm and a maximum transconductance of 320 mS/mm. In particular, this device produces excellent RF performance of small‐signal characteristics, such as a current gain cut‐off frequency ( f T ) of 55 GHz and maximum oscillation frequencies ( f max ) of 130 GHz.