PEER REVIEWED

2024

  1. A. Gustafsson, A. R. Persson, P. O. Å. Persson, V. Darakchieva, Z. Bi und L. Samuelson, Cathodoluminescence investigations of darkline defects in platelet-based InGaN nano-LED structures, Nanotechnology 35 (25), 255703 (2024). URL https://dx.doi.org/10.1088/1361-6528/ad33e9
  2. N. Armakavicius, S. Knight, P. Kühne, V. Stanishev, D. Q. Tran, S. Richter, A. Papamichail, M. Stokey, P. Sorensen, U. Kilic, M. Schubert, P. P. Paskov, V. Darakchieva; Electron effective mass in GaN revisited: New insights from terahertz and mid-infrared optical Hall effect. APL Mater. 12 (2): 021114 (2024). https://doi.org/10.1063/5.0176188
  3. S. Knight, S. Richter, A. Papamichail, M. Stokey, R. Korlacki, V. Stanishev, P. Kühne, M. Schubert und V. Darakchieva, Terahertz permittivity parameters of monoclinic single crystal lutetium oxyorthosilicate, Applied Physics Letters 124 (3), 032101 (2024). https://doi.org/10.1063/5.0177304
  4. D. Gogova, D. Q. Tran, V. Stanishev, V. Jokubavicius, L. Vines, M. Schubert, R. Yakimova, P. P. Paskov and V. Darakchieva, High crystalline quality homoepitaxial Si-doped β-Ga 2 O 3 (010) layers with re duced structural anisotropy grown by hot-wall MOCVD, Journal of Vacuum Science & Technology A 42 (2), 022708 (2024). URL https://doi.org/10.1116/6.0003424
  5. B. Sundarapandian, D. Q. Tran, L. Kirste, P. Straňák, A. Graff, M. Prescher, A. Nair, M. Raghuwanshi, V. Darakchieva, P. P. Paskov, O. Ambacher, Comparison of aluminum nitride thin films prepared by magnetron sputter epitaxy in nitrogen and ammonia atmosphere, Applied Physics Letters 124, 182101 (2024). URL https://doi.org/10.1063/5.0202161

2023

  1. V. Rindert, S. Richter, S. Knight, M. Schubert und V. Darakchieva, THz Spectroscopic Electron Paramagnetic Resonance of the Fe3+ Defect in GaN, in 2023 48th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz), 1–2 (2023). https://doi.org/10.1109/IRMMW-THz57677.2023.10299078
  2. A. M. Vidarsson, A. R. Persson, J.-T. Chen, D. Haasmann, J. U. Hassan, S. Dimitrijev, N. Rorsman, V. Darakchieva und E. Ö. Sveinbjörnsson, Observations of very fast electron traps at SiC/high-κ dielectric interfaces, APL Materials 11 (11), 111121 (2023). URL https://doi.org/10.1063/5.0160287
  3. S. Knight, S. Richter, A. Papamichail, P. Kühne, N. Armakavicius, S. Guo, A. R. Persson, V. Stanishev, V. Rindert, P. O. . Persson, P. P. Paskov, M. Schubert und V. Darakchieva, Room temperature two-dimensional electron gas scattering time, effective mass, and mobility parameters in AlxGa1−xN/GaN heterostructures (0.07 ≤ x ≤ 0.42), J. Appl. Phys. 134 (18), 185701 (2023). https://doi.org/10.1063/5.0163754
  4. D.-Y. Chen, K.-H. Wen, M. Thorsell, M. Lorenzini, H. Hjelmgren, J.-T. Chen und N. Rorsman, Impact of the Channel Thickness on Electron Confinement in MOCVD-Grown High Breakdown Buffer-Free Al-GaN/GaN Heterostructures, physica status solidi (a) 220 (16), 2200496 (2023). https://doi.org/10.1002/pssa.202200496
  5. T. Thingujam, M. Uren, N. Rorsman, M. Smith, A. Barnes, M. Brondi und M. Kuball, Origin of Transconductance roll-off in mmWave Al-GaN/GaN HEMTs, 2023 International Conference on Compound Semiconductor Manufacturing Technology, CS MANTECH 2023 – Orlando, FL, United States, CS MANTECH 2023 ; Conference date: 15-05-2023 Through 18-05-2023 (2023). https://csmantech.org/
  6. M. A. Mebarki, R. F.-D. D. Castillo, E. Sundin, D. Meledin, M. Thorsell, N. Rorsman, V. Belitsky und V. Desmaris, Comparison of the low noise performance of GaN HEMTs and MIS-HEMTs at cryogenic temperatures, in 2023 18th European Microwave Integrated Circuits Conference (EuMIC), 29–32 (2023). https://doi.org/10.23919/EuMIC58042.2023.10288670
  7. A. Divinyi, N. Rorsman, N. Billstr¨ om und M. Thorsell, Transition Time of GaN HEMT Switches and its Dependence on Device Geometry, in 2023 18th European Microwave Integrated Circuits Conference (EuMIC), 46–49 (2023). https://doi.org/10.23919/EuMIC58042.2023.10289035
  8. A. R. Persson, Anders Gustafsson, Zaoxia Bi, Lars Samuelsson, Vanya Darakchieva and P. O. A. Persson, Correlating cathodoluminescence and transmission electron microscopy for InGaN platelet nano-LEDs, Appl. Phys. Lett. 123, 022103 (2023). https://doi.org/10.1063/5.0150863
  9. V. Stanishev, N. Armakavicius, D. Gogova, M. Nawaz, N. Rorsman, P.P. Paskov and V. Darakchieva, Low Al-content n-type AlGaN layers with a high-electron-mobility grown by hot-wall metalorganic chemical vapor deposition, Vacuum 217, 112481 (2023). https://doi.org/10.1016/j.vacuum.2023.112481
  10. P. Gribisch, R. Delgado Carrascon, V. Darakchieva and E. Lind, Capacitance and mobility evaluation for normally-off fully-vertical GaN FinFETs, IEEE Trans. Electron. Dev. 70, 4101 (2023). https://doi.org/10.1109/TED.2023.3287820
  11. D.Q. Tran, T. Paskova, V. Darakchieva and P.P. Paskov, On the thermal conductivity anisotropy in GaN, AIP Adv.. 13, 095009 (2023). https://doi.org/10.1063/5.0167866
  12. Ding Yan Chen, Axel R. Persson, Vanya Darakchieva, P. O. A. Persson, Jr. Tai Chen and Niklas Rorsman, Structural investigation of ultra-low-resistance Ohmic contacts for AlGaN/GaN HEMTs based on Ti/Al/Ti-metallization, Semicond. Sci. Technol. 38, 105006 (2023). https://doi.org/10.1088/1361-6641/acf396
  13. H. Zhang, T. Chen, A. Papamichail, I. Persson, P. P. Paskov and V. Darakchieva, High-quality N-polar GaN optimization by multi-step temperature growth process, Journal of Crystal Growth 603, 127002 (2023). https://doi.org/10.1016/j.jcrysgro.2022.127002
  14. Papamichail, A. R. Persson, S. Richter, P. Kühne, V. Stanishev, P. O. Å. Persson, R. Ferrand-Drake Del Castillo, M. Thorsell, H. Hjelmgren, P. P. Paskov, N. Rorsman and V. Darakchieva, Tuning composition in graded AlGaN channel HEMTs toward improved linearity for low-noise radio-frequency amplifiers, Appl. Phys. Lett. 122 (15), 153501 (2023). https://doi.org/10.1063/5.0141517
  15. D. Q. Tran, F. Tasnádi, A. Žukauskaite, J. Birch, V. Darakchieva and P. P. Paskov, Thermal conductivity of ScxAl1-xN and YxAl1-xN alloys, Appl. Phys. Lett. 122 (18), 182107 (2023). https://doi.org/10.1063/5.0145847
  16. P. Gribisch, R. D. Carrascon, V. Darakchieva and E. Lind, Tuning of Quasi-Vertical GaN FinFETs Fabricated on SiC Substrates, IEEE T. Electron Dev. 70 (5), 2408 (2023). https://doi.org/10.1109/TED.2023.3263154
  17. H. Zhang, I. Persson, J.-T. Chen, A. Papamichail, D. Q. Tran, P. O. Å. Persson, P. P. Paskov and V. Darakchieva, Polarity Control by Inversion Domain Suppression in N-Polar III-Nitride Heterostructures, Cryst. Groth Des. 23 (2), 1049 (2023). https://doi.org/10.1021/acs.cgd.2c01199
  18. M. A. Mebarki, R. F.-D. D. Castillo, D. Meledin, E. Sundin, M. Thorsell, N. Rorsman, V. Belitsky und V. Desmaris, Noise Characterization and Modeling of GaN-HEMTs at Cryogenic Temperatures, IEEE T. Microw. Theory 71 (5), 1923 (2023). https://doi.org/10.1109/TMTT.2022.3226480

2022

  1. Kakanakova-Georgieva, A. Papamichail, V. Stanishev and V. Darakchieva, Incorporation of Magnesium into GaN Regulated by Intentionally Large Amounts of Hydrogen during Growth by MOCVD, Phys. Stat. Sol. (b) 259 (10), 2200137 (2022). https://doi.org/10.1002/pssb.202200137
  2. R. Delgado Carrascon, S. Richter, M. Nawaz, P. P. Paskov and V. Darakchieva, Hot-Wall MOCVD for High-Quality Homoepitaxy of GaN: Understanding Nucleation and Design of Growth Strategies, Crystal Growth & Design 22 (12), 7021 (2022). https://doi.org/10.1021/acs.cgd.2c00683
  3. M. Stokey, T. Gramer, R. Korlacki, S. Knight, S. Richter, R. Jinno, Y. Cho, H. G. Xing, D. Jena, M. Hilfiker, V. Darakchieva and M. Schubert, Infrared-active phonon modes and static dielectric constants in α-(AlxGa1-x)2O3 (0.18 ≤ x ≤ 0.54) alloys, Appl. Phys. Lett. 120 (11), 112202 (2022). https://doi.org/10.1063/5.0085958
  4. R. Persson, A. Papamichail, V. Darakchieva und P. O. Å. Persson, Mg segregation at inclined facets of pyramidal inversion domains in GaN:Mg, Sci. Rep. 12 (1), 17987 (2022). https://doi.org/10.1038/s41598-022-22622-1
  5. Papamichail, A. Kakanakova-Georgieva, E. Ö. Sveinbjörnsson, A. R. Persson, B. Hult, N. Rorsman, V. Stanishev, S. P. Le, P. O. Å. Persson, M. Nawaz, J. T. Chen, P. P. Paskov und V. Darakchieva, Mg-doping and free-hole properties of hot-wall MOCVD GaN, J. Appl. Phys. 131 (18), 185704 (2022). https://doi.org/10.1063/5.0089406
  6. D.-Y. Chen, K.-H. Wen, M. Thorsell, M. Lorenzini, H. Hjelmgren, J.-T. Chen und N. Rorsman, Impact of the Channel Thickness on Electron Confinement in MOCVD-Grown High Breakdown Buffer-Free AlGaN/GaN Heterostructures, Phys. Stat. Sol. (a) 2200496 (2022). https://doi.org/10.1002/pssa.202200496
  7. Kühne P., Armakavicius N., Papamichail A., Tran D., Stanishev V., Schubert M., Paskov P., and Darakchieva V., Enhancement of 2DEG effective mass in AlN/Al0.78Ga0.22N high electron mobility transistor structure determined by THz optical Hall effect, Appl. Phys. Lett. 120, 253102 (2022); https://doi.org/10.1063/5.0087033
  8. Gogova D., Ghezellou M., Tran D., Richter S., Papamichail A., ul-Hassan J., Persson A., Persson P., Kordina O., Monemar B., Hilfiker M., Schubert M., Paskov P., Darakchieva V., Epitaxial growth of β-Ga2O3 by hot-wall MOCVD, AIP Advances 12 055022 (2022); https://doi.org/10.1063/5.0087571
  9. Schubert M., Knight S., Richter S., Kühne P., Stanishev V., Ruder A., Stokey M., Korlacki R., Irmscher K., Neugebauer P., Darakchieva V., Terahertz electron paramagnetic resonance generalized spectroscopic ellipsometry: The magnetic response of the nitrogen defect in 4H-SiC, Appl. Phys. Lett. 120, 102101 (2022); https://doi.org/10.1063/5.0082353
  10. Korlacki R., Knudtson J., Stokey M., Hilfiker M., Darakchieva V., and Schubert M., Linear strain and stress potential parameters for the three fundamental band to band transitions in ?-Ga2O3, Appl. Phys. Lett. 120, 042103 (2022); https://doi.org/10.1063/5.0078157
  11. R. Korlacki, M. Hilfiker, J. Knudtson, M. Stokey, U. Kilic, A. Mauze, Y. Zhang, J. Speck, V. Darakchieva und M. Schubert, Strain and Composition Dependencies of the Near-Band-Gap Optical Transitions in Monoclinic (AlxGa1-x)2O3 Alloys with Coherent Biaxial In-Plane Strain on Ga2O3 (010), Phys. Rev. Appl. 18, 064019 (2022). https://doi.org/10.1103/PhysRevApplied.18.064019
  12. Kimel, A. Zvezdin, S. Sharma, S. Shallcross, N. de Sousa, A. García Martín, G. Salvan, J. Hamrle, O. Stejskal, J. McCord, S. Tacchi, G. Carlotti, P. Gambardella, G. Salis, M. Münzenberg, M. Schultze, V. Temnov, I. V. Bychkov, L. N. Kotov, N. Maccaferri, D. Ignatyeva, V. Belotelov, C. Donnelly, A. H. Rodriguez, I. Matsuda, T. Ruchon, M. Fanciulli, M. Sacchi, C. R. Du, H. Wang, N. P. Armitage, M. Schubert, V. Darakchieva, B. Liu, Z. Huang, B. Ding, A. Berger und P. Vavassori, The 2022 magneto-optics roadmap, J. Phys. D: Appl. Phys. 55 (46), 463003 (2022). https://dx.doi.org/10.1088/1361-6463/ac8da0
  13. Hult, M. Thorsell, J.-T. Chen und N. Rorsman, AlGaN/GaN/AlN ‘Buffer-Free’ High Voltage MISHEMTs with Si-rich and Stoichiometric SiNx First Passivation, in 2022 Compound Semiconductor Week (CSW), 1–2 (2022).
  14. R. F.-D. D. Castillo und N. Rorsman, Considerations in the development of a gate process module for ultra-scaled GaN HEMTs, in 2022 Compound Semiconductor Week (CSW), 1–2 (2022).
  15. Papamichail, A. R. Persson, S. Ricther, P. Kühne, P. O. Persson, M. Thorsell, H. Hjelmgren, N. Rorsman und V. Darakchieva, Compositionally graded channel HEMTs towards improved linearity for low-noise RF amplifiers, in 2022 Compound Semiconductor Week (CSW), 1–2 (2022).
  16. M. A. Mebarki, R. F.-D. D. Castillo, A. Pavolotskiy, D. Meledin, E. Sundin, M. Thorsell, N. Rorsman, V. Belitsky und V. Desmaris, GaN HEMT with superconducting Nb gates for low noise cryogenic applications, in 2022 Compound Semiconductor Week (CSW), 1–2 (2022).
  17. M. A. Mebarki, R. Ferrand-Drake Del Castillo, A. Pavolotsky, D. Meledin, E. Sundin, M. Thorsell, N. Rorsman, V. Belitsky und V. Desmaris, GaN High-Electron-Mobility Transistors with Superconducting Nb Gates for Low-Noise Cryogenic Applications, Phys. Stat. Sol. (a) 2200468 (2022). https://doi.org/10.1002/pssa.202200468
  18. Hult, M. Thorsell, J.-T. Chen und N. Rorsman, High Voltage and Low Leakage GaN-on-SiC MISHEMTs on a “Buffer-Free” Heterostructure, IEEE Electr. Device L. 43 (5), 781 (2022).
  19. Hult, M. Thorsell, J.-T. Chen und N. Rorsman, Investigation of Isolation Approaches and the Stoichiometry of SiN x Passivation Layers in “Buffer-Free” AlGaN/GaN Metal–Insulator–Semiconductor High-Electron-Mobility Transistors, Phys. Stat. Sol. (a) 2200533 (2022). https://doi.org/10.1002/pssa.202200533
  20. Harrysson Rodrigues, N. Rorsman und A. Vorobiev, Mobility and quasi-ballistic charge carrier transport in graphene field-effect transistors, J. Appl. Phys. 132 (24), 244303 (2022). https://doi.org/10.1063/5.0121439
  21. Q. Tran, R. D. Carrascon, M. Iwaya, B. Monemar, V. Darakchieva and P. P. Paskov, Thermal conductivity of AlxGa1-xN (0 ≤ x ≤ 1) epitaxial layers, Phys. Rev. Mater. 6, 104602 (2022). https://link.aps.org/doi/10.1103/PhysRevMaterials.6.104602
  22. Stokey M., Korlacki R., Hilfiker M., Knight S., Richter S., Darakchieva V., Jinno R., Cho Y., Xing H., Jena D., Oshima Y., Khan K., Ahmadi E., and Schubert M., Infrared dielectric functions and Brillouin zone center phonons of α-Ga2O3 compared to α-Al2O3, Phys. Rev. Materials 6, 014601 (2022), https://doi.org/10.1103/PhysRevMaterials.6.014601
  23. Chen D.-Y., Persson A., Wen K.-H., Sommer D., Grünenpütt J., Blanck H., Thorsell M., Kordina O., Darakchieva V., Persson P., Chen J.-T., and Rorsman N., Impact of in situ NH3 pre-treatment of LPCVD SiN passivation on GaN HEMT performance, Semicond. Sci. Technol. 37, 035011 (2022). https://doi.org/10.1088/1361-6641/ac4b17
  24. Zhang H., Persson I., Papamichail A., Chen, J.-T, Persson P., Paskov P., and Darakchieva V., On the polarity determination and polarity inversion in nitrogen-polar group III-nitride layers grown on SiC, Journal of Applied Physics 131, 055701 (2022); https://doi.org/10.1063/5.0074010

2021

  1. H.-Y. Lee, T.-W. Chang, E. Y. Chang, N. Rorsman und C.-T. Lee, Fabrication and Characterization of GaN-Based Fin-Channel Array Metal Oxide-Semiconductor High-Electron Mobility Transistors with Recessed Gate and Ga2O3 Gate Insulator Layer, IEEE Journal of the Electron Devices Society 9, 393 (2021). URL https://doi.org/10.1109/JEDS.2021.3069973
  2. Stokey M., Korlacki R., Knight S., Ruder A., Hilfiker M., Galazka Z., Irmscher K., Zhang Y., Zhao H., Darakchieva V. and Schubert M., Optical phonon modes, static and high frequency dielectric constants, and effective electron mass parameter in cubic In2O3, J. Appl. Phys. 129, 225102 (2021), https://doi.org/10.1063/5.0052848
  3. Tran D. Q., Carrascon R. D., Muth J. F., Paskova T., Nawaz M., Darakchieva V., Paskov P.P., Erratum “Boundary scattering and phonon transport in AlGaN: Effect of layer thickness” [Appl. Phys. Lett. 117, 252102 (2020)], Appl. Phys. Lett. 118, 189901 (2021), https://doi.org/10.1063/5.0054625
  4. J.-J. Jian, H.-Y. Lee, E. Y. Chang, N. Rorsman und C.-T. Lee, Investigation of Multiple-Mesa-Nanochannel Array GaN-Based MOSHEMTs with Al2O3 Gate Dielectric Layer, ECS Journal of Solid State Science and Technology 10 (5), 055017 (2021). URL https://doi.org/10.1149/ 2162-8777/ac029f

2020

  1. R. D. Carrascon, D. Q. Tran, P. Sukkaew, A. Mock, R. Ciechonski, J. Ohlsson, Y. Zhu, O. Hultin, B. Monemar, P. P. Paskov, L. Samuelson und V. Darakchieva, Optimization of GaN Nanowires Reformation Process by Metalorganic Chemical Vapor Deposition for Device-Quality GaN Templates, physica status solidi (b) 257 (4), 1900581 (2020). URL https://doi.org/10.1002/pssb.201900581
  2. D.-Y. Chen, A. Malmros, M. Thorsell, H. Hjelmgren, O. Kordina, J.-T. Chen und N. Rorsman, Microwave Performance of ‘Buffer-Free’ GaNon-SiC High Electron Mobility Transistors, IEEE Electron Device Letters 41 (6), 828 (2020). URL https://doi.org/10.1109/led.2020. 2988074
  3. J. Bremer, D. Y. Chen, A. Malko, M. Madel, N. Rorsman, S. E. Gunnarsson, K. Andersson, T. M. J. Nilsson, P. E. Raad, P. L. Komarov, T. L. Sandy und M. Thorsell, Electric-Based Thermal Characterization of GaN Technologies Affected by Trapping Effects, IEEE Transactions on Electron Devices 67 (5), 1952 (2020). URL https://doi.org/10.1109/ted.2020.2983277
  4. T. Huang, O. Axelsson, J. Bergsten, M. Thorsell und N. Rorsman, Impact of AlGaN/GaN Interface and Passivation on the Robustness of Low-Noise Amplifiers, IEEE Transactions on Electron Devices 67 (6), 2297 (2020). URL https://doi.org/10.1109/ted.2020.2986806
  5. M. Schubert, A. Mock, R. Korlacki, S. Knight, B. Monemar, K. Goto, Y. Kumagai, A. Kuramata, Z. Galazka, G. Wagner, M. J. Tadjer, V. D. Wheeler, M. Higashiwaki und V. Darakchieva, Phonon Properties, in Gallium Oxide, Springer International Publishing, 501–534 (2020). URL https://doi.org/10.1007/978-3-030-37153-1_28
  6. M. Stokey, A. Mock, R. Korlacki, S. Knight, V. Darakchieva, S. Schöche und M. Schubert, Infrared active phonons in monoclinic lutetium oxyorthosilicate, Journal of Applied Physics 127 (11), 115702 (2020). URL https://doi.org/10.1063/1.5135016
  7. D. Q. Tran, N. Blumenschein, A. Mock, P. Sukkaew, H. Zhang, J. F. Muth, T. Paskova, P. P. Paskov und V. Darakchieva, Thermal conductivity of ultra-wide bandgap thin layers – High Al-content AlGaN and β-Ga2O3, Physica B: Condensed Matter 579, 411810 (2020). URL https://doi.org/10.1016/j.physb.2019.411810
  8. R. Korlacki, A. Mock, C. Briley, V. Darakchieva, B. Monemar, Y. Kumagai, K. Goto, M. Higashiwaki und M. Schubert, Comment on “Characteristics of Multi-photon Absorption in a β-Ga2O3 Single Crystal” [J. Phys. Soc. Jpn. 88, 113701 (2019)], Journal of the Physical Society of Japan 89 (3), 036001 (2020). URL https://doi.org/10.7566/jpsj.89.036001
  9. H. Zhang, P. P. Paskov, O. Kordina, J.-T. Chen und V. Darakchieva, Npolar AlN nucleation layers grown by hot-wall MOCVD on SiC: Effects of substrate orientation on the polarity, surface morphology and crystal quality, Physica B: Condensed Matter 580, 411819 (2020). URL https://doi.org/10.1016/j.physb.2019.411819
  10. D. Q. Tran, R. Delgado-Carrascon, J. F. Muth, T. Paskova, M. Nawaz, V. Darakchieva und P. P. Paskov, Phonon-boundary scattering and thermal transport in AlxGa1-xN: Effect of layer thickness, Applied Physics Letters 117 (25), 252102 (2020). URL https://doi.org/10.1063/5.0031404
  11. P. Gopalan, S. Knight, A. Chanana, M. Stokey, P. Ranga, M. A. Scarpulla, S. Krishnamoorthy, V. Darakchieva, Z. Galazka, K. Irmscher, A. Fiedler, S. Blair, M. Schubert und B. Sensale-Rodriguez, The anisotropic quasi-static permittivity of single-crystal β-Ga2O3 measured by terahertz spectroscopy, Applied Physics Letters 117 (25), 252103 (2020). URL https://doi.org/10.1063/5.0031464
  12. R. Korlacki, M. Stokey, A. Mock, S. Knight, A. Papamichail, V. Darakchieva und M. Schubert, Strain and stress relationships for optical phonon modes in monoclinic crystals with β-Ga2O3 as an example, Physical Review B 102 (18) (2020). URL https://doi.org/10.1103/physrevb.102.180101
  13. S. Knight, S. Schöche, P. Kühne, T. Hofmann, V. Darakchieva und M. Schubert, Tunable cavity-enhanced terahertz frequency-domain optical Hall effect, Review of Scientific Instruments 91 (8), 083903 (2020). URL https://doi.org/10.1063/5.0010267
  14. M. Stokey, R. Korlacki, S. Knight, M. Hilfiker, Z. Galazka, K. Irmscher, V. Darakchieva und M. Schubert, Brillouin zone center phonon modes in ZnGa2O4, Applied Physics Letters 117 (5), 052104 (2020). URL https://doi.org/10.1063/5.0012526

2019

  1. J. Lu, J.-T. Chen, M. Dahlqvist, R. Kabouche, F. Medjdoub, J. Rosen, O. Kordina und L. Hultman, Transmorphic epitaxial growth of AlN nucleation layers on SiC substrates for high-breakdown thin GaN transistors, Applied Physics Letters 115 (22), 221601 (2019). URL https://doi.org/10.1063/1.5123374
  2. T. Huang, S. An, J. Bergsten, S. He und N. Rorsman, A power detector based on GaN high-electron-mobility transistors for a gigabit on–off keying demodulator at 90 GHz, Japanese Journal of Applied Physics 58 (SC), SCCD19 (2019). URL https://doi.org/10.7567/ 1347-4065/ab09d9
  3. M. Hilfiker, U. Kilic, A. Mock, V. Darakchieva, S. Knight, R. Korlacki, A. Mauze, Y. Zhang, J. Speck und M. Schubert, Dielectric function tensor (1.5 eV to 9.0 eV), anisotropy, and band to band transitions of monoclinic β-(AlxGa1–x)2O3 (x ≤ 0.21) films, Applied Physics Letters 114 (23), 231901 (2019). URL https://doi.org/10.1063/1.5097780
  4. Malmros, P. Gamarra, M. Thorsell, H. Hjelmgren, C. Lacam, S. L. Delage, H. Zirath und N. Rorsman, Impact of Channel Thickness on the Large-Signal Performance in InAlGaN/AlN/GaN HEMTs with an AlGaN Back Barrier, IEEE Transactions on Electron Devices 66 (1), 364 (2019). URL https://doi.org/10.1109/ted.2018.2881319
  5. Malmros, J.-T. Chen, H. Hjelmgren, J. Lu, L. Hultman, O. Kordina, E. O. Sveinbjornsson, H. Zirath und N. Rorsman, Enhanced Mobility in InAlN/AlN/GaN HEMTs Using a GaN Interlayer, IEEE Transactions on Electron Devices 66 (7), 2910 (2019). URL https://doi.org/10.1109/ted.2019.2914674
  6. M. Schubert, A. Mock, R. Korlacki, S. Knight, Z. Galazka, G. Wagner, V. Wheeler, M. Tadjer, K. Goto und V. Darakchieva, Longitudinal phonon plasmon mode coupling in β-Ga2O3, Applied Physics Letters 114 (10), 102102 (2019). URL https://doi.org/10.1063/1.5089145
  7. M. O. Eriksson, S. Khromov, P. P. Paskov, X. Wang, A. Yoshikawa, P. O. Holtz, B. Monemar und V. Darakchieva, Recombination processes in Mg doped wurtzite InN films with p- and n-type conductivity, AIP Advances 9 (1), 015114 (2019). URL https://doi.org/10.1063/1.5052432
  8. M. Schubert, A. Mock, R. Korlacki und V. Darakchieva, Phonon order and reststrahlen bands of polar vibrations in crystals with monoclinic symmetry, Physical Review B 99 (4) (2019). URL https://doi.org/10.1103/physrevb.99.041201
  9. R. Khosa, J. Chen, K. Pàlsson, R. Karhu, J. Hassan, N. Rorsman und E. Sveinbjörnsson, Electrical properties of 4H-SiC MIS capacitors with AlN gate dielectric grown by MOCVD, Solid-State Electronics 153, 52 (2019). URL https://doi.org/10.1016/j.sse.2018.12.016
  10. Mock, R. Korlacki, S. Knight, M. Stokey, A. Fritz, V. Darakchieva und M. Schubert, Lattice dynamics of orthorhombic NdGaO3, Physical Review B 99 (18) (2019). URL https://doi.org/10.1103/physrevb. 99.184302

2018

  1. T. Huang, H. Jiang, J. Bergsten, K. M. Lau und N. Rorsman, Enhanced gate stack stability in GaN transistors with gate dielectric of bilayer SiNx by low pressure chemical vapor deposition, Applied Physics Letters 113 (23), 232102 (2018). URL https://doi.org/10.1063/1.5042809
  2. S. Knight, A. Mock, R. Korlacki, V. Darakchieva, B. Monemar, Y. Kumagai, K. Goto, M. Higashiwaki und M. Schubert, Electron effective mass in Sn-doped monoclinic single crystal ?-gallium oxide determined by mid-infrared optical Hall effect, Applied Physics Letters 112 (1), 012103 (2018). URL https://doi.org/10.1063/1.5011192
  3. N. Armakavicius, V. Stanishev, S. Knight, P. Kühne, M. Schubert und V. Darakchieva, Electron effective mass in In0.33Ga0.67N determined by mid-infrared optical Hall effect, Applied Physics Letters 112 (8), 082103 (2018). URL https://doi.org/10.1063/1.5018247
  4. P. Kühne, N. Armakavicius, V. Stanishev, C. M. Herzinger, M. Schubert und V. Darakchieva, Advanced Terahertz Frequency-Domain Ellipsometry Instrumentation for In Situ and Ex Situ Applications, IEEE Transactions on Terahertz Science and Technology 8 (3), 257 (2018). URL https://doi.org/10.1109/tthz.2018.2814347
  5. Y.-K. Lin, J. Bergsten, H. Leong, A. Malmros, J.-T. Chen, D.-Y. Chen, O. Kordina, H. Zirath, E. Y. Chang und N. Rorsman, A versatile lowresistance ohmic contact process with ohmic recess and low-temperature annealing for GaN HEMTs, Semiconductor Science and Technology 33 (9), 095019 (2018). URL https://doi.org/10.1088/1361-6641/ aad7a8
  6. J.-T. Chen, J. Bergsten, J. Lu, E. Janzén, M. Thorsell, L. Hultman, N. Rorsman und O. Kordina, A GaN–SiC hybrid material for highfrequency and power electronics, Applied Physics Letters 113 (4), 041605 (2018). URL https://doi.org/10.1063/1.5042049
  7. J. Bremer, J. Bergsten, L. Hanning, T. Nilsson, N. Rorsman, S. Gustafsson, A. M. Eriksson und M. Thorsell, Analysis of Lateral Thermal Coupling for GaN MMIC Technologies, IEEE Transactions on Microwave Theory and Techniques 66 (10), 4430 (2018). URL https://doi.org/10.1109/TMTT.2018.2848932
  8. C. Sánchez-Pérez, C. M. Andersson, K. Buisman, D. Kuylenstierna,N. Rorsman und C. Fager, Design and Large-Signal Characterization of High-Power Varactor-Based Impedance Tuners, IEEE Transactions on Microwave Theory and Techniques 66 (4), 1744 (2018). URL https://doi.org/10.1109/TMTT.2018.2791969
  9. T. Huang, J. Bergsten, M. Thorsell und N. Rorsman, Small- and Large-Signal Analyses of Different Low-Pressure-Chemical-Vapor-Deposition SiNx Passivations for Microwave GaN HEMTs, IEEE Transactions on Electron Devices 65 (3), 908 (2018). URL https://doi.org/10.1109/ TED.2017.2789305
  10. J. Bergsten, M. Thorsell, D. Adolph, J.-T. Chen, O. Kordina, E. O. Sveinbjornsson und N. Rorsman, Electron Trapping in Extended Defects in Microwave AlGaN/GaN HEMTs with Carbon-Doped Buffers, IEEE Transactions on Electron Devices 65 (6), 2446 (2018). URL https://doi.org/10.1109/ted.2018.2828410

DOCTORAL THESIS

LICENTIATE THESES

MASTER THESIS

  • Kevin Ohlsson, “Optimization of Uniformity in Enhancement of Metal Organic Chemical Vapor Deposition Growth”, Linköping University, Linköping https://liu.diva-portal.org/smash/record.jsf?pid=diva2:1323031
  • Kai-Hsin Wen, “Study of ohmic contact formation on AlGaN/GaN heterostructures”, Chalmers University of Technology and KTH” http://urn.kb.se/resolve?urn=urn%3Anbn%3Ase%3Akth%3Adiva-259746
  • Oscar Johansson, “Transition Time Impairment of GaN Switches in Electromagnetic Harsh Environments”, Chalmers University of Technology and Saab
  • Emil Bjärehäll, “Power System-on-Chip for Future Airborne Sensor Systems Feasibility Analysis”, Chalmers University of Technology and Saab
  • Laurenz Geihofer, “Epitaxial growth and basic material characterization of β-Ga2O3“, Linköping University and Graz University of Technology
  • Yin Zeng, “Characterization and modeling of static and dynamic breakdown characteristics of AlGaN/GaN HEMTs”, Chalmers University of Technology, 2020
  • Kristófer Kristinsson, “GaN FiNFETs”, Chalmers University of Technology, 2021
  • Albert Malmros, “Investigation on the Optimization of GaN Etching for FinFET Applications”, Lund University, 2022 https://www.eit.lth.se/sprapport.php?uid=1433
  • Shiqi Guo, “AlGaN/GaN HEMTs for high-frequency applications”, Linköping University, 2022
  • Andri Dhora, “Development of thick GaN and AlGaN drift layers for vertical power devices”, Lund University August 2023 link

BACHELOR THESIS

  • Shiqi Guo, “AlGaN/GaN HEMTs with varying Al content barrier layers”, Linköping University: Linköping

CONFERENCE CONTRIBUTIONS

14th ICNS, November 12 – 17 | Fukuoka, Japan

  • A. Papamichail et. al. “Tuning composition in graded AlGaN channel and high-Al content AlGaN/GaN HEMTs for high frequency and high linearity applications” (talk)
  • I. Persson et. al. “High-quality N-polar GaN/AlGaN/GaN/AlN HEMTs by multistep temperature and supersaturation regime growth on off-cut SiC substrates” (talk)
  • B. So et. al. “Strain and Energy Band Engineering in thick AlGaN Drift Layers for High Power Vertical Transistors” (talk)
  • P. Gribisch et. al. “Vertical GaN FinFET devices on SiC and GaN substrates” (talk)
  • R. M. Ferrand-Drake del Castillo et. al. “Impact of Carbon Doping Levels in AlGaN Back-Barriers for GaN HEMTs” (talk)
  • K. Wen et. al. “Investigation of leakage path in buffer-free heterostructure” (talk)
  • D. Q. Tran et. al. “Effect of Donor and Acceptor Doping on the Thermal Conductivity of GaN” (poster)
  • S. Richter et. al. “Spectroscopic ellipsometry evaluation of damage and its recovery in Mg-implanted GaN” (poster)
  • A. R. Persson et. al. “Study of stacking mismatch boundaries in InGaN platelet red nanoLEDs” (poster)
  • N. Armakavicius et. al. “THz ellipsometry and optical Hall effect of group-III-Nitride epitaxial layers and device structures” (poster)
  • Viktor Rindert et. al. “Frequency Domain THz-EPR of the Fe 3+ Defect in GaN” (poster)
  • A. Divinyi et. al., “Transition Time of GaN HEMT Switches and its Dependence on Device Geometry” (talk)
  • M. A. Mebarki et. al., “Comparison of the low noise performance of GaN HEMTs and MIS-HEMTs at cryogenic temperatures” (talk)

Euro Nano Forum 2023, June 11 – 13 | Lund, Sweden

  • V. Darakchieva, “Next generation semiconductors for future sustainable electronics” (Invited talk)

WOCSDICE – EXMATEC 2023, May 21-25, 2023 | Palermo, Italy

  • A. Papamichail et. al., “Tunning composition in graded channel and high-Al content AlGaN barrier HEMTs” (Talk)

AVS 69, November 5 – 10 | Portland (OR), USA

  • V. Darakchieva, “Enhancement of Electron Effective Mass in Semiconductor Materials and 2DEGs Revealed by THz Optical Hall Effect” (Invited talk)

244th ECS Meeting, October 8-12, 2023 | Gothenburg, Sweden

  • V. Darakchieva, “Hot-wall MOCVD of next generation wide and ultra-wide band gap semiconductors for green electronics” (Invited talk)

IWGO2022, October 2022 | Nagano, Japan

  • D. Gogova et. al., “A new approach to β-Ga2O3 epitaxy” (Talk)
  • S. Richter et. al., “THz electron paramagnetic resonance ellipsometry – a new high precision tool to identify defects in gallium oxide: the case of iron doping” (Poster)
  • M. Stokey et. al., “Electronic and optical properties of monoclinic gallium oxide under strain: the full picture” (Poster)

IWN 2022, October 2022 | Berlin, Germany

  • V. Darakchieva et. al., “Honorary lecture for Bo Monemar” (Plenary talk)
  • A. Person et. al., “Spectroscopic and high-resolution identification of Mg causing GaN pyramidal inversion domains limiting p-type doping” (Talk)
  • R. Delgado-Carrascon et. al., “Understanding homoepitaxial GaN growth by hot-wall MOCVD” (Talk)
  • D. Tran et. al., “Thermal conductivity characterization of (Y, Sc)AlN alloys” (Talk)
  • D.-Y. Chen et. al., “Improve 2DEG confinement in 70 nm AlGaN/GaN HEMTs by reducing the GaN channel thickness in buffer-free heterostructures” (Talk)
  • H. Zhang et. al., “Multi-step temperature growth process optimization of N-polar GaN and its application to HEMT structures” (Poster)
  • S. Knight et. al., “Anomalous transport properties of the two-dimensional electron gas in GaN-based high-electron-mobility transistor structures” (Talk)
  • S. Richter et. al., “Mobility limitations for 2DEGs in AlGaN/GaN HEMT structures depending on the Al content in the AlGaN barrier” (Talk)
  • A. Papamichail et. al., “Compositionally graded channel HEMTs for improved linearity in low-noise RF amplifiers” (Poster)
  • N. Armakavicius et. al., “Temperature-dependent electron effective mass in bulk GaN revealed by terahertz optical Hall effect” (Poster)
  • P. Kühne et. al., “Anisotropic transport in N-polar GaN/AlGaN/GaN HEMTs grown on off-cut SiC substrates” (Poster)

EMRS 2022 Fall Meeting, September 2022 | Warsaw University of Technology, Poland

  • R. Delgado-Carrascon et. al., “Hot-wall MOCVD growth of low Al content, high electron mobility n-type AlxGa1-xN layers” (Talk)
  • V. Darakchieva et. al., “Hot-wall MOCVD of beta-Ga2O3 and defect characterization by advanced THz-EPR-Ellipsometry” (Invited talk)
  • P. Gribisch et. al., “Fabrication of quasi-vertical GaN FinFETs on SiC substrates” (Talk)

Defects in Solids for Quantum Technologies DSQT 2022, June 2022 | Stockholm, Sweden

  • V. Darakchieva et. al., “Terahertz Electron Paramagnetic Resonance ellipsometry for interrogating point defects in ultrawide bandgap semiconductors” (Invited talk)

CSW 2022, June 2022 | University of Michigan in Ann Arbor, USA

  • A. Papamichail et. al., “Compositionally graded channel HEMTs towards improved linearity for low-noise RF amplifiers” (Talk)
  • B. Hult et. al., “AlGaN/GaN/AlN ‘Buffer-Free’ High Voltage MISHEMTs with Si-rich and Stoichiometric SiNx First Passivation” (Talk)
  • R. Del Castillio et. al., “Considerations in the development of a gate process module for ultra-scaled GaN HEMTs” (Poster)
  • M. Mebarki et. al., “GaN HEMT with superconducting Nb gates for low noise cryogenic applications” (talk)

9th international conference on spectroscopic ellipsometry (ICSE-9), May 2022 | Beijing, China

  • V. Darakchieva, ”When Spectroscopic ellipsometry goes Terahertz”, (Tutorial)
  • S. Richter et. al., “Electron spin resonances at single crystal semiconductors measured by THz ellipsometry” (Talk)
  • S. Richter et. al., “Effective uniaxial dielectric function tensor to study optical phonons in β-Ga2O3 films with rotational domains” (Poster)
  • S. Richter et. al., “Anharmonicity in the Drude-Lorentz and Kukharskii models for the dielectric function” (Poster)
  • M. Hilfiker et. al., “The influence of strain and alloying onto the exciton and band-to-band transitions in (AlxGa1-x)2O3” (Talk)
  • M. Hilfiker et. al., “Phonons and band-to-band transitions in zinc gallate – a combined density functional theory and ellipsometry approach” (Talk)

EXMATEC 2021, June 2021 | Bristol, United Kingdom (online)

  • V. Darakchieva et. al., “Terahertz optical Hall effect and Terahertz EPR-ellipsometry of ultrawide bandgap and low-dimensional semiconductor systems” (Invited talk)

E-MRS 2021 Spring Meeting, May 2021 | (online)

  • S. Knight et. al., “Fabry-Pérot Enhanced Terahertz Mueller Matrix Ellipsometry for Materials Characterization” (Invited talk)

International Conference on Compound Semiconductor Manufacturing Technology (CS MANTECH), May 2021 | (online)

  • D.-Y. Chen et. al., “Thin Al0.5Ga0.5N/GaN HEMTs on QuanFINE® Structure” (Talk)

CSW 2021, May 2021 | Stockholm, Sweden (online)

  • A. Papamichail et. al., “Low Resistivity P-GaN Grown By Hot-wall MOCVD” (Talk)
  • H. Zhang et. al., “Polarity determination and inversion in nitrogen-polar group III-nitride films” (Talk)
  • J. ul Hassan et. al., “CVD Growth and Properties of β-Ga2O3 Epitaxial Layers” (Invited talk)
  • M. Ghezellou et. al., “Hot-Wall MOCVD Epitaxial Growth Of β-Gallium Oxide On Sapphire” (Talk)
  • D. Tran et. al., “Thermal Conductivity Of Wide-bandgap Semiconductors Beyond The Debye Approximation” (Talk)
  • R. Delgado-Carrascon et. al., “Homoepitaxial Growth Of GaN By Hot-wall MOCVD: Thermal Stability And Effect Of H2” (Talk)
  • P. Kühne et. al., “Two-dimensional Electron Gas In AlN/Al0.78Ga0.22N High Electron Mobility Transistor Structure Detected By THz Optical Hall Effect” (Poster)
  • R. Delgado-Carrascon et. al., “Hot-wall MOCVD Growth Of Low Al Content, High Electron Mobility N-type AlxGa1-xN Layers” (Poster)

INMMiC 2020, July 2020 | Cardiff, United Kingdom

  • I. Angelov, G. Granstrom, M. Gavell, M. Ferndahl, N. Rorsman, A. P. Ortega, “On the delay implementation in FET Large Signal Models” (Talk)

66th AVS conference, October 2019 | Columbus (OH) USA

  • A. Mock, S. Knight, M. Hilfiker, R. Korlacki, A. Papamichail, M.J. Tadjer, V. Darakchieva, and M. Schubert, “The Physics of Low Symmetry Metal Oxides: Applications of Ellipsometry” (Invited talk)

APWS 2019, November 2019 | Okinawa, Japan

  • M. Schubert, A. Mock, R. Korlacki, S. Knight, V. Darakchieva, S. Galazka, G. Wagner, H. Murakami, Y. Kumagai, K. Goto, M. Higashiwaki, and J. Speck. “Phonons, free charge carriers, excitons and band-to-band transitions in β-Ga2O3 and related alloys determined by ellipsometry and optical Hall effect” (Invited talk)

TCO2019, September 2019 | Leipzig, Germany

  • V. Darakchieva, “Paul Drude Lecture II: Optical properties of the electron gas” (Invited talk)

8th international conference on spectroscopic ellipsometry (ICSE-8), May 2019 | Barcelona, Spain

  • N. Armakavicius, P. Kuehne, V. Stanishev, S. Knight, T. Hofmann, C.M., Herzinger, M. Schubert, and V. Darakchieva “Stealth Technology-Based Terahertz Frequency-Domain Ellipsometry for In-situ and Ex-situ Applications” (Invited talk)
  • P. Kühne, N. Armakavicius, V. Stanishev, Jr-Tai Chen, O. Kordina, M. Schubert, and V. Darakchieva “Field- and temperature-dependent optical Hall effect in group-III nitrides” (Talk)
  • A. Mock, R. Korlacki, S. Knight, Z. Galazka, G. Wagner, V. Wheeler, M. Tadjer, K. Goto, and V. Darakchieva M. Schubert “Longitudinal phonon plasmon mode coupling and the strain-stress relationships in β-Ga2O3” (Talk)
  • A. Mock, R. Korlacki, S. Knight, M. Tadjer, V. Darakchieva, and M. Schubert “Generalized Ellipsometry on Low Symmetry Materials” (Invited talk)
  • S. Knight, M. Schubert, C. Binek, D. Prabhakaran, A. Lipatov, and A. Sinitskii, “Fabry-Perot Enhanced Terahertz Mueller Matrix Ellipsometry for Materials Characterization” (Invited talk)

13th International Conference on Nitride Semiconductors (ICNS-13) , July 2019 |Bellevue USA

  • D. Y. Chen, Jr. Tai Che, O. Kordina, N. Rorsman, “QuanFINE – High RF Performance AlGaN/AlN/GaN HEMTs with a Thin Buffer Layer” (Talk)
  • Rosalia Delgado-Carrascon, Dat Tran, Pitsiri Sukkaew, Alyssa Mock, Plamen P. Paskov, Rafal Ciechonski, Jonas Ohlsson, Yadan Zhu, Bo Monemar, Lars Samuelson and Vanya Darakchieva, “High quality GaN templates by coalescence overgrowth of GaN nanowires by MOCVD” (Poster)
  • Dat Q. Tran, Pitsiri Sukkaew, Hengfang Zhang, Jr-Tai Chen, Motoaki Iwaya, Isamu Akasaki, Bo Monemar, Vanya Darackchieva, Plamen P. Paskov, “Thermal conductivity of AlGaN layers grown by MOCVD” (Poster)
  • Hengfang Zhang, Ingemar Persson, Per Persson, Alyssa Mock, Pitsiri Sukkaew, Jr-Tai Chen and Vanya Darakchieva, “Polarity control in hot-wall MOCVD III-Nitride epitaxy on on-axis and vicinal SiC (000-1) substrates” (Poster)

21st International Vacuum Congress (IVC-21), July 2019 | Malmö, Sweden

  • Rosalia Delgado-Carrascon, Dat Tran, Pitsiri Sukkaew, Alyssa Mock, Plamen P. Paskov, Rafal Ciechonski, Jonas Ohlsson, Yadan Zhu, Bo Monemar, Lars Samuelson and Vanya Darakchieva, “High quality GaN templates by coalescence overgrowth of GaN nanowires by MOCVD” (Talk)
  • Hengfang Zhang, Plamen Paskov, Olof Kordina, Jr. Tai Chen, Vanya Darakchieva “N-polar epitaxy of III Nitrides by hot wall MOCVD” (Talk)
  • Olof Kordina “QuanFINE as RF and power device material” (Invited talk)

8th South African Conference on Photonic Materials, May 2019 | Kariega, South Africa

  • P. Kühne, Armakavicius, N. Stanishev, V. Chen, J.-T.; Kordina, O. Schubert, M. Darakchieva, V. Free “Charge Carrier Properties in Group-III Nitride High Electron Mobility Transistor Structures Determined by Optical Hall Effect” (Talk)
  • H. Zhang, Persson, I. Persson, P. Mock, A. Sukkaew, P. Chen, J.-T. Darakchieva, V. “A Comprehensive Study of AlN Nucleation Layers Grown onto On-Axis and 4° off-Axis SiC (000-1) Substrates and Its Influence on GaN Growth” (Talk)
  • D. Q. Tran, Sukkaew, P. Mock, A. Zhang, H. Blumenschein, N. Muth, John F. Paskov, P. P. Darackchieva, V. “Thermal Conductivity of Ultra-Wide Bandgap Thin Layers: High-Al Content AlGaN and β-Ga2O3” (Poster)
  • V. Darackchieva, “Free charge carrier properties and phonon-plasmon coupling in ultrawide band gap semiconductors” (Invited talk)

SPIE Opto Photonics West 2019, February 2019 | San Francisco (CA) USA

  • M. Schubert, A. Mock, R. Korlacki, S. Knight, V. Darakchieva, S. Galazka, G. Wagner, H. Murakami, Y. Kumagai, K. Goto, M. Higashiwaki, and J. Speck. “Phonon-plasmon coupling in monoclinic symmetry Ga2O3” (Invited talk)

10th International Workshop on Nitride Semiconductors (IWN2018), November 2018 | Kanazawa, Japan

  • P. Sukkaew, Rönnby, K. Chen, J.-T. Zhang, H. Ojamäe, L. Darakchieva, V. “Investigation of Growth Mode in AlN Buffer Layer for Strain and Dislocation Control in Al-Rich AlGaN Using Hot-Wall MOCVD” (Poster)
  • H. Zhang, Persson, I. Persson, P. Mock, A. Sukkaew, P. Chen, J.-T. Darakchieva, V. “Comparative Study of GaN Grown on On-Axis and Vicinal SiC (000-1) Substrates by Hot-Wall MOCVD” (Poster)

European Microwave week (CSW2018), September 2018 | Madrid, Spain

  • I. Angelov, “Modeling Semiconductor devices for PA” (Invited talk)

7th International Symposium on Growth of Nitride Semiconductors (ISGN-7), August 2018 | Warsaw, Poland

  • H. Zhang, Sukkaew, P. Chen J.-T. and Darakchieva, V. “Hot-wall MOCVD growth of N-polar AlN nucleation layers on C-face vicinal and on-axis SiC substrates” (Talk)

GaN Marathon 2.0, April 2018 | Padova, Italy

  • Jr. Tai Chen ”A revolutionaryy GaN-on-SiC epitaxy for high frequency power transistors” (Invited talk)

Compound Semiconductor Week (CSW2018), May 2018 | MIT Boston (MA), USA

  • J. Bergsten et. al., “Influence of Fe- And C-doped Buffers on Microwave Output Power and Dynamic Effects in AlGaN/GaN HEMTs” (Talk)
  • I. Angelov et al., “On the large Signal Modeling of MM wave GaAs PIN diodes” (Poster)