Projects

National

Transit2D – Tranzistory na báze 2D kovových chalkogenidov pripravených teplom podporovanou konverziou
Transistors based on 2D Metal Chalcogenides Grown via Thermally Assisted Conversion
Program: SRDA
Project leader: Ing. Ťapajna Milan, PhD.
Annotation: 2D materials can form one-atom-thick sheets with extraordinary properties. One of the most promising classes of2D materials is the transition metal dichalcogenides (TMDs). The transition from an indirect to a direct bandgap,when the bulk materials is thinned down to a monolayer, results in unique electrical and optical properties of 2DTMDs. Post-transition metal chalcogenides (PTMCs) represents another interesting group of 2D materials. Thesematerials have wide band gap and, depending on the structure of the material, show anisotropic electrical andoptical properties. The aim of this project is the fabrication of field-effect transistors with metal-oxide-semiconductorgate (MOSFETs) based on selected TMDs and PTMCs compounds and detail analysis of their transport properties.We will focus on large-area few-layer PtSe2 and GaS/GaSe films grown by thermal assisted conversion, i.e.sulfurization and selenization. Based on the existing experiences, structural, chemical and electrical properties ofhorizontally-aligned PtSe2 films prepared by selenization will be optimized, targeting mobilities similar to thoseprepared by mechanical exfoliation. Then, MOSFET technology using both, top-gate as well as bottom-gateapproach will be developed and optimized. Atomic layer deposition and metal-oxide chemical vapor deposition(MOCVD) will be employed for gate oxide growth. GaS/GaSe few-layer films will be prepared by chalcogenization
Duration: 1.7.2022 – 30.6.2026
Moderné elektronické súčiastky na báze ultraširokopásmového polovodiča Ga2O3 pre budúce vysokonapäťové aplikácie
Modern electronic devices based on ultrawide bandgap semiconducting Ga2O3 for future high-voltage applications
Program: SRDA
Project leader: Ing. Gucmann Filip, PhD.
Annotation: Wide bandgap (WBG) semiconductor devices represent one of the key technologies in development of high power and high frequency systems for electric power conversion and telecommunications owing to their fundamental benefit of higher breakdown electric fields, in some cases increased electron mobility, and possibility to form heterostructures and 2D electron gas. GaN and SiC, two typical WBG examples also benefit from moderate values of thermal conductivity allowing for more efficient sinking of generated waste heat, lower channel temperatures, and enhanced device reliability. New emerging semiconductor materials with even higher bandgap energies (Eg>3.4eV) referred to as ultrawide bandgap materials allow for further improvements in high power and high voltage handling solid-state electronic devices. Currently, semiconducting gallium oxide (Ga2O3) is under extensive study and expected to provide base material for rectifying Schottky -gate diodes and field-effect transistors for applications operating in kV range thanks to its good scalability, relatively simple synthesis, availability of native melt-grown substrates, and wide range of achievable n-type doping levels. The main aim of the proposed project constitutes material research and development of technology for epitaxial growth of epitaxial α -,β-, and ε-Ga2O3 layers and for processing of basic unipolar and bipolar electronic devices based on prepared Ga2O3 layers for future high voltage/power applications. Ga2O3 layers will be grown using liquid injection metalorganic chemical vapour deposition on sapphire, and higher thermal conductivity SiC substrates. We also aim to prepare Schottky diodes, FETs, and all-oxide Ga2O3 PN diodes using naturally p-type oxides (e.g. NiO, In2O3, CuO2). Comprehensive structural, electrical, optical, and thermal study of prepared epitaxial layers and devices will be conducted and numerous original, high-impact results are expected to be obtained.
Duration: 1.7.2021 – 30.6.2025
NanoMemb-RF – Moderné nanomembránové heteroštruktúry na báze GaAs pre vysoko produktívne vysokofrekvenčné prvky
Advanced GaAs-based nanomembrane heterostructures for highperformance RF devices
Program: SRDA
Project leader: RNDr. Gregušová Dagmar, DrSc.
Annotation: The main aim of the proposed project is to expand the basic knowledge and to master the fabrication technology ofthe advanced nanomembrane AlGaAs/GaAs heterojunction devices for high-performance RF applications.Insufficient removal of the waste heat in electronic devices due to the Joule losses leading to overheating and earlydevice failure often requires foreign, high thermal conductivity substrates to be employed. As opposed to themainstream research of the GaN-based electronic devices prepared directly on sapphire or SiC, proposed GaAsbased devices will be fabricated upon self-supporting heterostructure nanomembranes transferred onto varioussubstrates. It is very timely, original, and desirable approach to extend the utilization of the GaAs-based devicesmaterial potential, as demonstrated by our preliminary results.
Duration: 1.7.2022 – 30.6.2025
PEGANEL – p-GaN elektronika pre úsporu energie a post-CMOS obvody
p-GaN electronics for energy savings and beyond-CMOS circuits
Program: SRDA
Project leader: Ing. Kuzmík Ján, DrSc.
Annotation: III-N semiconductors are probably the most versatile and promising semiconductor family, consisted of artificialcompounds made of GaN, AlN and InN. In the project proposal we describe new technological concepts withsufficient freedom to solve main problems of the III-N post-beyond CMOS age: in transistors co-existence of theparasitic n-channel along with the p-channel, as well as low hole gas density and mobility. Similarly, we aim todemonstrate scalable threshold voltage in the enhancement-mode p-doped power transistors, which are needed bythe industry for efficient, energy-saving convertors. In these aspects, our laboratories already showed verypromising results proving the competence to reach described targets. If successfully implemented, results of ourproposed project would represent a significant step forward not only from the world-wide point of view but is also infull agreement with the RIS3 SK (perspective areas of specialization of the Slovak economy), particularly in thefield of semiconductors for electric cars of automotive industry, as well as in information and communicationsciences.
Duration: 1.7.2022 – 30.6.2025
Elektronické a optoelektronické súčiastky na báze ultra-širokopásmového Ga2O3 polovodiča
Electronic and optoelectronic devices based on ultra-wide bandgap Ga2O3 semiconductor
Program: VEGA
Project leader: Ing. Ťapajna Milan, PhD.
Annotation: Recently, great research effort has been devoted to ultra-wide bandgap semiconductors for the preparation ofhigh-performance electronic devices operating in the electric fields up to tens of kV and UV photodetectors. Thisproject aims the research of the growth of epitaxial layers and electronic as well as optoelectronic devices basedon Ga2O3. Based on preliminary results, we will investigate the growth of rhombohedral Ga2O3 with the highestbandgap energy. Epitaxial layers will be prepared by metal-organic chemical vapor deposition using liquid phaseprecursor injection. The layers will be used for preparation and research of electronic devices with a focus onSchottky diodes and switching MOSFET transistors. We will study the transport and thermal properties, parasiticeffects and breakdown mechanisms of the developed electronic devices as well as electro-optical properties ofp-n heterojunctions. We will also target exploratory research for improvements in thermal management of thepower transistors.
Duration: 1.1.2021 – 31.12.2024
Systematický výskum Ohmických kontaktov pre súčiastky na báze romboedrického oxidu gália (alfa-Ga2O3)
Systematic investigation of Ohmic contacts for devices based on rhombohedral gallium oxide (alfa-Ga2O3)
Program: DoktoGrant
Project leader: Mgr. Egyenes Fridrich, PhD.
Duration: 1.1.2021 – 31.12.2021