Citation
Romero Rojo, Fátima and Jiménez Martín, Ana and González Posadas, Vicente and Martin Horcajo, Sara and Calle Gómez, Fernando and Muñoz Merino, Elias
(2012).
Impact of N2 plasma power discharge on AlGaN/GaN HEMT performance.
"IEEE Transactions on Electron Devices", v. 59
(n. 2);
pp. 374-379.
ISSN 0018-9383.
https://doi.org/10.1109/TED.2011.2176947.
Abstract
The effects of power and time conditions of in situ N2 plasma treatment, prior to silicon nitride (SiN) passivation, were investigated on an AlGaN/GaN high-electron mobility transistor (HEMT). These studies reveal that N2 plasma power is a critical parameter to control the SiN/AlGaN interface quality, which directly affects the 2-D electron gas density. Significant enhancement in the HEMT characteristics was observed by using a low power N2 plasma pretreatment. In contrast, a marked gradual reduction in the maximum drain-source current density (IDS max) and maximum transconductance (gm max), as well as in fT and fmax, was observed as the N2 plasma power increases (up to 40% decrease for 210 W). Different mechanisms were proposed to be dominant as a function of the discharge power range. A good correlation was observed between the device electrical characteristics and the surface assessment by atomic force microscopy and Kelvin force microscopy techniques.