TY - JOUR AU - Baji, Zsófia AU - Pécz, Béla AU - Fogarassy, Zsolt AU - Szabó, Zoltán AU - Cora, Ildikó TI - Atomic layer deposited Fe-sulphide layers with pyrrhotite structure controlled by the deposition temperature JF - THIN SOLID FILMS J2 - THIN SOLID FILMS VL - in press PY - 2024 SN - 0040-6090 DO - 10.1016/j.tsf.2024.140267 UR - https://m2.mtmt.hu/api/publication/34714394 ID - 34714394 AB - Atomic layer deposition was used to grow epitaxial iron sulphide layers on α-Al2O3 substrates. According to the transmission electron microscopic measurements, these Fe-sulphide films had 1C pyrrhotite structure (Fe1-xS). In the case of pyrrhotite materials, both the magnetic and electric properties depend significantly on their iron content and on the ordering of iron vacancies. By tuning the parameters of the atomic layer deposition method, the structure of epitaxial pyrrhotite films could be controlled, thus the electronic properties of the Fe1-xS films could be influenced: At deposition temperatures below 350°C, the structure contained many faults, and the layers were n type semiconductors, while at higher temperatures, the resulting films were p-type with excellent crystalline structures with disordered vacancies. A post deposition annealing could further improve the crystallinity and induce p-type conductivity. LA - English DB - MTMT ER - TY - JOUR AU - Fogarassy, Zsolt AU - Wójcicka, Aleksandra AU - Cora, Ildikó AU - Rácz, Adél Sarolta AU - Grzanka, Szymon AU - Dodony, Erzsébet AU - Perlin, Piotr AU - Borysiewicz, Michał A. TI - Structural and electrical investigation of Al/Ti/TiN/Au based N-face n-GaN contact stack JF - MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING J2 - MAT SCI SEMICON PROC VL - 175 PY - 2024 PG - 12 SN - 1369-8001 DO - 10.1016/j.mssp.2024.108250 UR - https://m2.mtmt.hu/api/publication/34714097 ID - 34714097 AB - In this work, the structure of Ti/Al/TiN/Au contact layer stack on the N-face of a single-crystal n-GaN substrate is studied after heat treatment at 750 °C. Since TiN is widely regarded as a diffusion barrier in the stack, the formed structures with three different initial TiN thicknesses (15, 60 and 90 nm) in the contact layers are investigated in detail. The primary tool used for the structural investigations was a (scanning) transmission electron microscope ((S)TEM). In all three samples a low resistivity ohmic contact was formed. However, the TiN layer has not completely blocked the diffusion for any of the samples and both Al and Au diffused through the TiN layer at the temperature of 750 °C. As a result of the heat treatment, a complex AlN/TiN/Au2Al/TiN/Au + Al2.67O4 stack was formed on the surface of the GaN substrate. The measurements have not shown the often reported Ti–Al alloy phase in the samples. The formation of the AlN and TiN layers can be explained by the separation of N from GaN creating N vacancies in the GaN substrate which could help the formation of the ohmic behavior. LA - English DB - MTMT ER - TY - JOUR AU - Galizia, Bruno AU - Fiorenza, Patrick AU - Schilirò, Emanuela AU - Pécz, Béla AU - Fogarassy, Zsolt AU - Greco, Giuseppe AU - Saggio, Mario AU - Cascino, Salvatore AU - Lo, Nigro Raffaella AU - Roccaforte, Fabrizio TI - Towards aluminum oxide/aluminum nitride insulating stacks on 4H–SiC by atomic layer deposition JF - MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING J2 - MAT SCI SEMICON PROC VL - 174 PY - 2024 PG - 7 SN - 1369-8001 DO - 10.1016/j.mssp.2024.108244 UR - https://m2.mtmt.hu/api/publication/34653875 ID - 34653875 AB - Stacked aluminum oxide/aluminum nitride (Al2O3/AlN) layers were deposited on n-type (0001) 4H–SiC by atomic layer deposition (ALD) processes. The structural and chemical properties have been investigated and are consistent with the growth of ∼9 nm oriented (0001) AlN layer, and an upper 20 nm amorphous Al2O3 layer. The entire Al2O3/AlN stack was electrically characterized and compared with respect to a single Al2O3 layer having the same total thickness. The Al2O3/AlN bilayer exhibited a higher dielectric constant (κ = 8.7), a significant reduction of the oxide trapped charges (NOT) from 7.8 × 1012 to 1.8 × 1012 cm−2, as well as a decrease of a factor 2 of the interface traps density (Dit) compared with the Al2O3 single layer values. A large positive flat band voltage shift was observed in the C–V curves acquired on MIS capacitors. The comparison of the behaviour of MIS capacitors fabricated on both n-type and p-type 4H–SiC demonstrated that deep interface states (near the 4H–SiC mid gap) acting as acceptors or donors for the n-type and p-type MIS contribute to the observed behavior. This hypothesis has been also corroborated by TCAD simulations. LA - English DB - MTMT ER - TY - JOUR AU - Galizia, Bruno AU - Fiorenza, Patrick AU - Bongiorno, Corrado AU - Pécz, Béla AU - Fogarassy, Zsolt AU - Schilirò, Emanuela AU - Giannazzo, Filippo AU - Roccaforte, Fabrizio AU - Nigro, Raffaella Lo TI - Structural and electrical correlation in aluminum nitride thin films grown by plasma enhanced atomic layer deposition as interface insulating layers on silicon carbide (4H-SiC) JF - MICROELECTRONIC ENGINEERING J2 - MICROELECTRON ENG VL - 283 PY - 2024 PG - 7 SN - 0167-9317 DO - 10.1016/j.mee.2023.112103 UR - https://m2.mtmt.hu/api/publication/34193521 ID - 34193521 LA - English DB - MTMT ER - TY - JOUR AU - Cadena Nogales, Ana Cristina AU - Pekker, Áron AU - Botka, Bea AU - Dodony, Erzsébet AU - Fogarassy, Zsolt AU - Pécz, Béla AU - Kamarás, Katalin TI - Encapsulation of the Graphene Nanoribbon Precursor 1, 2, 4‐trichlorobenzene in Boron Nitride Nanotubes at Room Temperature JF - PHYSICA STATUS SOLIDI - RAPID RESEARCH LETTERS J2 - PHYS STATUS SOLIDI-R VL - 17 PY - 2023 IS - 1 PG - 5 SN - 1862-6254 DO - 10.1002/pssr.202200284 UR - https://m2.mtmt.hu/api/publication/33138741 ID - 33138741 LA - English DB - MTMT ER - TY - CONF AU - Dodony, Erzsébet AU - Dódony, István AU - Fogarassy, Zsolt AU - Pekker, Péter AU - Sáfrán, György ED - Gábor, Steinbach TI - DIFFRAKCIÓS INTENZITÁS MÉRÉSEK TEM-BEN II.: AZ EWALD KORREKCIÓ KITERJESZTÉSE. Diffracted intensity measurements in TEM II.: Extension of the Ewald correction TS - Diffracted intensity measurements in TEM II.: Extension of the Ewald correction T2 - A Magyar Mikroszkópos Társaság éves konferenciájának kivonatkönyve 2023 : Book of the Abstracts of the Annual Conference of HSM 2023 PY - 2023 SP - 28 EP - 31 PG - 4 UR - https://m2.mtmt.hu/api/publication/34487420 ID - 34487420 N1 - Előadás LA - English DB - MTMT ER - TY - CONF AU - Dodony, Erzsébet AU - Dódony, István AU - Fogarassy, Zsolt AU - Pekker, Péter AU - Sáfrán, György ED - Gábor, Steinbach TI - A γ -NIKKEL-SZILICID SZERKEZETI VÁLTOZATOSSÁGA. Structural variability of the γ-nickel-silicide TS - Structural variability of the γ-nickel-silicide T2 - A Magyar Mikroszkópos Társaság éves konferenciájának kivonatkönyve 2023 : Book of the Abstracts of the Annual Conference of HSM 2023 PY - 2023 SP - 26 EP - 28 PG - 3 UR - https://m2.mtmt.hu/api/publication/34487369 ID - 34487369 N1 - Előadás LA - English DB - MTMT ER - TY - JOUR AU - Fogarassy, Zsolt AU - Kentsch, U. AU - Panjan, P. AU - Rácz, Adél Sarolta TI - Experimental and theoretical study on the production of carbide-rich composite nano-coatings JF - SURFACES AND INTERFACES J2 - SURF INTERFACES VL - 38 PY - 2023 PG - 8 SN - 2468-0230 DO - 10.1016/j.surfin.2023.102773 UR - https://m2.mtmt.hu/api/publication/33686168 ID - 33686168 AB - Carbides are known for high hardness and corrosion resistance and therefore applicable as protective coatings. C/Si and C/W multilayers (the individual layer thicknesses were between 10 and 20 nm) have been irradiated at room temperature by argon and xenon ions. The energies varied between 40 and 120 keV while the fluences were in the range of 0.07 - 6 × 1016 ions/cm2. The SRIM simulation was applied to have the proper ion energy. The irradiation induced intermixing and carbide (SiC and WC) formation at the interfaces already for the lowest irradiation fluence. The component in-depth distribution has been determined by AES depth profiling which showed that it varied greatly as a function of the irradiation conditions and layer structure. In both material pair the thickness of the produced carbide increased with square root of fluence but the mixing mechanism were different: local spike for C/W and ballistic for C/Si. The mixing efficiency was lower for the C/Si than for the C/W. LA - English DB - MTMT ER - TY - JOUR AU - Galkin, Nikolay G. AU - Galkin, Konstantin N. AU - Goroshko, Dmitrii L. AU - Dotsenko, Sergei A. AU - Kropachev, Oleg V. AU - Chernev, Igor M. AU - Subbotin, Evgenii Yu AU - Alekseev, Aleksey Yu AU - Migas, Dmitry B. AU - Fogarassy, Zsolt AU - Pécz, Béla AU - Gutakovskii, Anton K. TI - Ca silicide films-promising materials for silicon optoelectronics JF - JAPANESE JOURNAL OF APPLIED PHYSICS (2008) J2 - JPN J APPL PHYS VL - 62 PY - 2023 IS - SD PG - 20 SN - 0021-4922 DO - 10.35848/1347-4065/aca0fd UR - https://m2.mtmt.hu/api/publication/33535224 ID - 33535224 AB - Single-phase films of semiconductor and semimetallic calcium silicides (Ca2Si, CaSi, and CaSi2), as well as films with a significant contribution of Ca5Si3 and Ca14Si19 silicides, were grown on single-crystal silicon and sapphire substrates. The analysis of the crystal structure of the grown films was carried out and the criterion of their matching with silicon and sapphire substrates was determined. Some lattice-matching models were proposed, and the subsequent deformations of the silicide lattices were estimated. Film's optical functions, including the optical transparency, were calculated from the optical spectroscopy data and an extended comparison was performed with the results of ab initio calculations. The real limits of the optical transparency for the films on sapphire substrates were established. The maximum transparency limit (3.9 eV) was observed for the CaSi film. Based on an analysis of the photoelectric properties of Ca2Si/Si diodes on n- and p-type silicon substrates, a perspective of their applications in silicon optoelectronics was discussed. LA - English DB - MTMT ER - TY - JOUR AU - Maj, Ł. AU - Fogarassy, Zsolt AU - Wojtas, D. AU - Jarzębska, A. AU - Muhaffel, F. AU - Sulyok, Attila AU - Góral, A. AU - Kulczyk, M. AU - Çimenoğlu, H. AU - Bieda, M. TI - In-situ formation of Ag nanoparticles in the MAO coating during the processing of cp-Ti JF - SCIENTIFIC REPORTS J2 - SCI REP VL - 13 PY - 2023 IS - 1 PG - 7 SN - 2045-2322 DO - 10.1038/s41598-023-29999-7 UR - https://m2.mtmt.hu/api/publication/33733765 ID - 33733765 LA - English DB - MTMT ER -