Nanoelectronics, Defects in electronic materials, Radiation damage, Semiconductor processing, nonvolatile memories


Dr Vassilios Ioannou-Sougleridis graduated from the Physics Department of the University of Athens (BSc) in 1985. He received his MSc degree from the Physics Department of Brunel University in 1987 on the field of Technology and physics of semiconductors, with dissertation thesis title “The size reduction of semiconductor devices and the physical limitations of integrated circuits”. His Ph.D. degree was entitled “point defect studies in SIMOX structures” and was received from the Physics Department of the University of Athens (BSc) in 1993.

In 1996 he joined the Institute of Microelectronics of NCSR-D working as a post-doctoral research scientist, in the field of silicon nanocrystals embedded within an insulator matrix for light emission and memory applications. His main task was the fabrication of silicon based light emission structures their electrical and optical characterization.

From 2005 his research interests expanded in thin film high-k insulator materials, Ge technology (including Ge p-n junctions, dopant diffusion in Ge, and Ge MOS devices) epitaxial strained silicon on Si-Ge substrates, non-volatile memory stacks fabricated by Low-Energy Ion beam synthesis, and ALD alumina films applications in micro-nanoelectronics.

Since 2017 he is a research director at the INN of NCSR-D and his main research interests at present are:

  1. Performance improvement studies of MANOS charge trap memory devices using ALD High-k dielectrics (Al2O3, HfO2, ZrO2) as control oxides. Investigation of the high-k dielectrics properties upon ALD chemistry. Studies on the footprint of standard wet semiconductor processing in ALD-Al2O3 stacks are carried out by assessing their electrical performance, for the development of an appropriate processing scheme.
  2. Development of an alternative method of n-type doping in Ge, based on nitrogen-phosphorus co-implantation techniques. Determination of the post-implantation annealing thermal process parameters. Studies of Ge substrate damage due to excess thermal budget. Studies on the parameters that control the interface trap density of the Ge-dielectric interface.
  3. Development of dedicated techniques to detect electronic traps in thick insulator and ceramic materials, targeting radiation induced damage studies on functional materials by high fluence (deuterium-tritium) neutron at the JET Tokamak reactor. This activity is carried out within the frame of EUROFUSION FP-8 and FP-9 programme and acts as P.I.


Vasileiadis, N., Karakolis, P., Mandylas, P., Ioannou-Sougleridis, V., Normand, P., Perego, M., Komninou, P., Ntinas, V., Fyrigos, I.-A., Karafyllidis, I., Sirakoulis, G.C. and Dimitrakis, P., Understanding the Role of Defects in Silicon Nitride-Based Resistive Switching Memories through Oxygen Doping IEEE Transactions on Nanotechnology, Volume 20, Pages: 356-364, Article Number: 9403953, 2021 [doi]

Ioannou-Sougleridis, V., Alafakis, S., Vouroutzis, N.Z., Mergia, K., Speliotis, A. and Skarlatos, D., Degradation of Pt-Al2O3-Ge metal oxide semiconductor structures due to Pt-Al2O3 induced reactions ECS Journal of Solid State Science and Technology, Volume 9, 2020 [doi]

Skarlatos, Dimitrios, Ioannou-Sougleridis, Vassilios, Barozzi, Mario, Pepponi, Giancarlo, Vouroutzis, Nikolaos Zisis, Velessiotis, Dimitrios, Stoemenos, John, Zographos, Nikolas and Colombeau, Benjamin P, Issues with n-type Dopants in Germanium ECS Transactions, IOP Publishing, Volume 86, Pages: 51, 2018 [doi]

Skarlatos, D., Ioannou-Sougleridis, V., Barozzi, M., Pepponi, G., Velessiotis, D., Skoulikidou, M.C., Vouroutzis, N.Z., Papagelis, K., Dimitrakis, P., Thomidis, C. and Colombeau, B., Phosphorous diffusion in N2+-implanted germanium during flash lamp annealing: Influence of nitrogen on ge substrate damage and capping layer engineering ECS Journal of Solid State Science and Technology, Volume 6, Pages: P418-P428, 2017 [doi]

Kruse, J.E., Lymperakis, L., Eftychis, S., Adikimenakis, A., Doundoulakis, G., Tsagaraki, K., Androulidaki, M., Olziersky, A., Dimitrakis, P., Ioannou-Sougleridis, V., Normand, P., Koukoula, T., Kehagias, T., Komninou, P., Konstantinidis, G. and Georgakilas, A., Selective-area growth of GaN nanowires on SiO2-masked Si (111) substrates by molecular beam epitaxy Journal of Applied Physics, Volume 119, 2016 [doi]

Simatos, DP, Dimitrakis, P, Normand, P, Nikolaou, N, Giannakopoulos, K, Ladas, S, P'ecassou, B'eatrice and Benassayag, G'erard and Ioannou-Sougleridis, V, Temperature dependent retention characteristics of ion-beam modified SONOS memories Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, North-Holland, Volume 365, Pages: 66–69, 2015 [doi]

Nikolaou, N., Ioannou-Sougleridis, V., Dimitrakis, P., Normand, P., Skarlatos, D., Giannakopoulos, K., Kukli, K., Niinist"o, J. and Ritala, M., The effect of oxygen source on atomic layer deposited Al2O 3 as blocking oxide in metal/aluminum oxide/nitride/oxide/silicon memory capacitors Thin Solid Films, Volume 533, Pages: 5-8, 2013 [doi]

Bonafos, C., Carrada, M., Benassayag, G., Schamm-Chardon, S., Groenen, J., Paillard, V., Pecassou, B., Claverie, A., Dimitrakis, P., Kapetanakis, E., Ioannou-Sougleridis, V., Normand, P., Sahu, B. and Slaoui, A., Si and Ge nanocrystals for future memory devices Materials Science in Semiconductor Processing, Volume 15, Pages: 615-626, 2012 [doi]

Ioannou-Sougleridis, V, Kelaidis, N, Skarlatos, D, Tsamis, C, Georga, SN, Krontiras, CA, Komninou, Ph, Speliotis, Th, Dimitrakis, P, Kellerman, B and others, Influence of thermal oxidation on the interfacial properties of ultrathin strained silicon layers Thin solid films, Elsevier, Volume 519, Pages: 5456–5463, 2011 [doi]

Dimitrakis, P., Ioannou-Sougleridis, V., Normand, P., Bonafos, C., Schamm-Chardon, S., Mouti, A., Schmidt, B. and Becker, J., Formation of Ge nanocrystals in high-k dielectric layers for memory applications Volume 1250, Pages: 69-74, 2010 [doi]

Dimitrakis, P., Mouti, A., Bonafos, C., Schamm, S., Ben Assayag, G., Ioannou-Sougleridis, V., Schmidt, B., Becker, J. and Normand, P., Ultra-low-energy ion-beam-synthesis of Ge nanocrystals in thin ALD Al2O3 layers for memory applications Microelectronic Engineering, Volume 86, Pages: 1838-1841, 2009 [doi]

Kelaidis, N, Ioannou-Sougleridis, Vassilios, Skarlatos, D, Tsamis, C, Krontiras, CA, Georga, SN, Kellerman, B and Seacrist, M, Influence of thermal processing on the electrical characteristics of MOS capacitors on strained-silicon substrates Thin solid films, Elsevier, Volume 517, Pages: 350–352, 2008 [doi]

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