GaN and III-N device research

Gallium Nitride (GaN) and related compounds commonly referred as III-N have significantly more flexible energy gap, higher breakdown electric field intensity, a large spontaneous polarization, high thermal and radiation resistance, but also the high mobility of electrons as compared to the classic semiconductors such as Si, GaAs and InP and related compounds. Therefore the electronic devices based on III-N semiconductors can withstand significantly higher operation voltages and temperatures (above 300 ºC) allowing for realization of devices for a higher output power and smaller physical volume. The III-N material may also exhibit the highest possible frequency along with the highest level of the breakdown voltage combined within the compared materials. Therefore there is an effort to develop III-N semiconductor devices, mainly Heterostructure Field Effect Transistors (HFETs) with/without insulated gate. Such transistors have the potential to gradually replace Si, Si/SiGe, GaAs and InP devices in microwave and power applications, switches, switching amplifiers, logic circuits and mixed-signal electronics. By term “advanced” we understand application of concepts which incorporate novel physical phenomena and unique technologies.

Consequently, in this manner we aspire to develop:

  • HEMTS with InN channel for ultrafast information transfer.

  • Advanced GaN-based transistor switches for energy conversion.

  • Technology of GaN-based fast mixed-signal circuits.

  • GaN-based UV sensors for space applications.


Chauhan, P., Hasenöhrl, S., Dobročka, E., Vančo Ľ., Stoklas, R., Kováč, J., Šiffalovič, P., and Kuzmík, J.: Effect of temperature and carrier gas on the properties of thick InxAl1-xN layer, Applied Surface Sci 470 (2019) 1-7.

Hasenöhrl, S., Chauhan, P., Dobročka, E., Stoklas, R., Vančo, Ľ., Veselý, M., Bouazzaoui, F., Chauvat, M.-P., Reterana, P., and Kuzmík, J.: Generation of hole gas in non-inverted InAl(Ga)N/GaN heterostructures, Applied Phys. Express 12 (2019) 014001.

Kučera, M., Adikimenakis, A., Dobročka, E., Kúdela, R., Ťapajna, M., Laurenčíková, A., Georgakilas, A., and Kuzmík, J.: Structural, electrical, and optical properties of annealed InN films grown on sapphire and silicon substrates, Thin Solid Films 672 (2019) 114-119.

Gucmann, F., Ťapajna, M., Pohorelec, O., Haščík, Š., Hušeková, K., and Kuzmík, J.: Creation of two-dinesional electron gas and role of surface donors in III-N metal-oxide-semiconductor high-electron mobility transistors, Phys. Status Solidi A 215 (2018) 1800090.

Stoklas, R., Gregušová, D., Hasenöhrl, S., Brytavskyi, I.V., Ťapajna, M., Fröhlich, , Haščík, Š., Gregor, M., and Kuzmík, J.: Characterization of interface states in AlGaN/GaN metal-oxide-semiconductor heterostructure field-effect transistors with HfO2 gate dielectric grown by atomic layer deposition, Applied Surface Sci 461 (2018) 255-259.

Dobročka, E., Hasenöhrl, S., Chauhan, P., and Kuzmík, J.: Non-conventional scans in high-resolution X-ray diffraction analysis of epitaxial systems, Applied Surface Sci 461 (2018) 23-32.

Hashizume, T., Nishiguchi, K., Kaneki, S., Kuzmik, J., and Yatabe, Z.: State of the art on gate insulation and surface passivation for GaN-based power HEMTs, Mater. Sci in Semicond. Process. 78 (2018) 85-95.

Chvála, A., Nagy, L., Marek, J., Priesol, J., Donoval, D., Blaho, M., Gregušová, D., Kuzmík, J., and Šatka, A.: Characterization of monolithic InAlN/GaN NAND logic cell supported by circuit and device simulations, IEEE Trans. Electron Devices 65 (2018) 2666-2669.

Blaho, M., Gregušová, D., Haščík, Š., Ťapajna, M., Fröhlich, K., Šatka, A., Kuzmík, J., : Annealing, temperature, and bias-induced threshold voltage instabilities in integrated E/D-mode InAlN/GaN MOS HEMTs. Applied Phys. Lett. 111 (2017) 033506. (APVV 15-0673). (CENTE).

Graff, A., Simon-Najasek, M., Altmann, F., Kuzmík, J., Gregušová, D., Haščík, Š., Jung, J., Baur, T., Grunenputt, J., and Blanck, H.: High resolution physical analysis of ohmic contact formation at GaN-HEMT devices, Microelectron. Reliab. 76-77 (2017) 338.

Kuzmík, J., Fleury, C., Adikimenakis, A., Gregušová, D., Ťapajna, M., Dobročka, E., Haščík, Š., Kučera, M., Kúdela, R., Androulidaki, M., Pogany, D., Georgakilas, A., : Current conduction mechanism and electrical break-down in InN grown on GaN. Applied Phys. Lett. 110 (2017) 232103. (APVV 15-0031). (CENTE II).

Ťapajna, M., Stoklas, R., Gregušová, D., Gucmann, F., Hušeková, K., Haščík, Š., Fröhlich, K., Tóth, L., Pecz, B., Brunner, F., Kuzmík, J., : Investigation of ‘surface donors’ in Al2O3/AlGaN/GaN metal-oxide-semiconductor heterostructures: Correlation of electrical, structural, and chemical properties. Applied Surface Sci 426 (2017) 656-661. (CENTE II). (APVV 15-0031). (VEGA 2/0138/14).

Ťapajna, M., Válik, L., Gucmann, F., Gregušová, D., Fröhlich, K., Haščík, Š., Dobročka, E., Tóth, L., Pecz, B.,Kuzmík, J., : Low-temperature atomic layer deposition-grown Al2O3 gate dielectric for GaN/AlGaN/GaN MOS HEMTs: Impact of deposition conditions on interface state density. J. Vacuum Sci Technol. B 35 (2017) 01A107. (SAFEMOST). (VEGA 2/0138/14). (CENTE).

Gregušová, D., Blaho, M., Haščík, Š., Šichman, P., Laurenčíková, A., Seifertová, A., Dérer, J., Brunner, F., Würfl, H., Kuzmík, J., : Polarization-engineered n+GaN/InGaN/AlGaN/GaN normally-off MOS HEMTs. Physica Status Solidi a 214 (2017) 1700407. (HiPoSwitch). (APVV 15-0031). (SAFEMOST). (VEGA 2/0109/17).

Ťapajna, M., Hilt, O., Bahat-Triedel, E., Würfl, H., Kuzmík, J., : Gate reliability investigation in normally-off p-type-gan cap/AlGaN/GaN HEMTs under forward bias stress. IEEE Electron Device Lett. 37 (2016) 385 – 388.

Matys, M., Stoklas, R., Kuzmík, J., Adamowicz, J., Yatabe, Z., Hashizume, T., : Characterization of capture cross sections of interface states in dielectric/III-nitride heterojunction structures. J. Applied Phys. 119 (2016) 205304.

Blaho, M., Gregušová, D., Haščík, Š., Seifertová, A., Ťapajna, M., Šoltýs, J., Šatka, A., Nagy, L., Chvála, A., Marek, J., Carlin, J., Grandjean, N., Konstantinidis, G., Kuzmík, J., : Technology of integrated self-aligned E/D-mode n++GaN/InAlN/AlN/GaN MOS HEMTs for mixed-signal electronics. Semicond. Sci Technol. 31 (2016) 065011. (CENTE). (APVV 0367-11). (VEGA 2/0138/14).

Kuzmík, J., Haščík, Š., Kučera, M., Kúdela, R., Dobročka, E., Adikimenakis, A., Mičušík, M., Gregor, M., Plecenik, A., Georgakilas, A., : Elimination of surface band bending on N-polar InN with thin GaN capping,. Applied Phys. Lett. 107 (2015) 191605. (APVV 0367-11). (VEGA 2/0138/14). (CENTE).

Ťapajna, M., Hilt, O., Bahat-Triedel, E., Würfl, H., Kuzmík, J., : Investigation of gate-diode degradation in normally-off p-GaN/AlGaN/GaN high-electron-mobility transistors. Applied Phys. Lett. 107 (2015) 193506.(HiPoSwitch). (VEGA 2/0138/14). (CENTE).

Blaho, M., Gregušová, D., Haščík, Š., Jurkovič, M., Ťapajna, M., Fröhlich, K., Dérer, J., Carlin, J., Grandjean, N., Kuzmík, J., : Self-aligned normally-off metal-oxide-semiconductor n+++GaN/InAlN/GaN high-electron mobility transistors. Phys. Status Solidi A 112 (2015) 1086-1090. (MORGaN). (APVV 0367-11). (VEGA 2/0138/14). (CENTE).

Gregušová, D., Jurkovič, M., Haščík, Š., Blaho, M., Seifertová, A., Fedor, J., Ťapajna, M., Fröhlich, K., Vogrinčič, P., Liday, J., Derluyn, J., Germain, M., Kuzmík, J., : Adjustment of threshold voltage in AlN/AlGaN/GaN high-electron mobility transistors by plasma oxidation and Al2O3 atomic layer deposition overgrowth. Applied Phys. Lett. 104 (2014) 013506. (HiPoSwitch). (APVV 0367-11). (VEGA 2/0105/13).

Kuzmík, J., Jurkovič, M., Gregušová, D., Ťapajna, M., Brunner, F., Cho, E., Meneghesso, G., Würfl, H., :Degradation of AlGaN/GaN high-electron mobility transistors in the current-controlled off-state breakdown. J. Applied Phys. 115 (2014) 164504. (HiPoSwitch). (CENTE II). (APVV 0104-10).

Ťapajna, M., Jurkovič, M., Válik, L., Haščík, Š., Gregušová, D., Brunner, F., Cho, E., Hashizume, T., Kuzmík, J., : Impact of GaN cap on charges in Al2O3/(GaN/)AlGaN/GaN metal-oxide-semiconductor heterostructures analyzed by means of capacitance measurements and simulations. J. Applied Phys. 116 (2014) 104501.(HiPoSwitch). (CENTE). (APVV 0367-11). (VEGA 2/0138/14).