%0 Journal Article
%A Mikulics, M.
%A Hardtdegen, Hilde
%A Arango, Yulieth
%A Adam, Roman
%A Fox, Alfred
%A Grützmacher, Detlev
%A Gregušová, D.
%A Stanček, S.
%A Novák, J.
%A Kordoš, P.
%A Sofer, Z.
%A Juul, L.
%A Marso, M.
%T Reduction of skin effect losses in double-level-T-gate structure
%J Applied physics letters
%V 105
%N 23
%@ 1077-3118
%C Melville, NY
%I American Inst. of Physics
%M FZJ-2015-02658
%P 232102
%D 2014
%X We developed a T-gate technology based on selective wet etching yielding 200 nm wide T-gate structures used for fabrication of High Electron Mobility Transistors (HEMT). Major advantages of our process are the use of only  standard photolithographic process and the ability to generate T-gate stacks. A HEMT fabricated on AlGaN/GaN/sapphire with gate length Lg¼200 nm and double-stacked T-gates exhibits 60 GHz cutoff frequency showing ten-fold improvement compared to 6 GHz for the same device with 2 lm gate length. HEMTs with a double-level-T-gate (DLTG) structure exhibit up to 35% improvement of fmax value compared to a single T-gate device. This indicates a significant reduction of skin effect losses in DLTG structure compared to its standard T-gate counterpart. These results agree with the theoretical predictions.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000346266000044
%R 10.1063/1.4903468
%U https://juser.fz-juelich.de/record/189501