Reduction of skin effect losses in double-level-T-gate structure
English
Mikulics, Martin[Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, D-52425 Jülich, Germany and Jülich-Aachen Research Alliance, JARA, Fundamentals of Future Information Technology, Germany]
Hardtdegen, Hilde[Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, D-52425 Jülich, Germany and Jülich-Aachen Research Alliance, JARA, Fundamentals of Future Information Technology, Germany]
Arango, Y. C.[Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, D-52425 Jülich, Germany and Jülich-Aachen Research Alliance, JARA, Fundamentals of Future Information Technology, Germany]
Adam, Roman[Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, D-52425 Jülich, Germany and Jülich-Aachen Research Alliance, JARA, Fundamentals of Future Information Technology, Germany]
Fox, Alfred[Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, D-52425 Jülich, Germany and Jülich-Aachen Research Alliance, JARA, Fundamentals of Future Information Technology, Germany]
Grützmacher, Detlev[Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, D-52425 Jülich, Germany and Jülich-Aachen Research Alliance, JARA, Fundamentals of Future Information Technology, Germany]
Gregušová, Dagmar[Institute of Electrical Engineering, Slovak Academy of Sciences, SK-84104 Bratislava, Slovak Republic]
Stanček, Stanislav[Department of Nuclear Physic and Technique, Slovak University of Technology, SK-81219 Bratislava, Slovak Republic]
Novák, Jozef[Institute of Electrical Engineering, Slovak Academy of Sciences, SK-84104 Bratislava, Slovak Republic]
Kordoš, Peter[Institute of Electrical Engineering, Slovak Academy of Sciences, SK-84104 Bratislava, Slovak Republic, and Department of Microelectronics, Slovak University of Technology, SK-81219 Bratislava, Slovak Republic]
Sofer, Zdenĕk[Department of Inorganic Chemistry, Institute of Chemical Technology, Technická 5, 166 28 Prague 6, Czech Republic]
Juul, Lars[University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Engineering Research Unit >]
Marso, Michel[University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Engineering Research Unit >]
[en] 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 Lg=200 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 um 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.