With plasma, everything is possible.
Group leader: Assoc. Prof. Lenka Zajíčková, Ph.D.
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ORCID: 0000-0002-6906-8906
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Open Ph.D. topics
See also the list of topics at CEITEC website and general information about the PhD programme.
Plasma etching and polishing of SiC in low pressure plasma
SiC provides several advantages over silicon in semiconductor applications: 10× higher dielectric breakdown field strength, 2× higher electron saturation velocity, 3× higher energy band gap, and 3× higher thermal conductivity. The drawbacks are the SiC wafer cost and availability. Thus, key improvements and innovations are needed in SiC surface polishing, which is extremely difficult due to its high hardness and chemical and thermal stability. One of the promising techniques used in the development of SiC polishing is plasma etching. This thesis aims to deepen the understanding of how various plasma discharges interact with the SiC surface to propose optimized processes for industrial applications. Thus, the Ph.D. candidate will collaborate closely with the Czech branch of ONSEMI in Rožnov. The SiC reactive ion etching (RIE) will be investigated in a radio frequency (RF) inductively coupled plasma (ICP) in which the processed wafer can be biased by RF or LF (low frequency) voltage. The etching and polishing processes will be influenced by the choice of working gases (e.g., Ar, oxygen, SF₆) and the variations of the ion energy distribution function. Basic research on the ion interaction with the SiC surface will also use reactive ion beam etching (RIBE), in which the ion energy is precisely defined by its accelerating voltage, and it is also possible to vary the angle of incidence of the ions by tilting the substrate. Surface conditions will be analyzed regarding roughness and depth of the damaged layer by, e.g., atomic force microscopy (AFM), ellipsometry, optical Raman or fluorescence microscopy, surface composition, and crystallinity analyses. The epitaxial growth of SiC will test surface quality.
Plasma modifications of polymer surfaces at atmospheric pressure
Plasma treatment and plasma enhanced chemical vapor deposition are highly efficient technologies for the modification of polymer surfaces because the processes take advantage of a highly reactive plasma environment, enabling low processing temperatures. The technologies are dry and, therefore, belong to ecological alternatives to chemical modification of surfaces that require large amounts of liquid chemicals. However, the complexity of plasma-surface interactions hinders the entire understanding and optimization of the processes. The thesis aims to improve the knowledge base for the plasma treatment of polymers by atmospheric pressure plasma jets. One of the tasks will be to understand the factors influencing the strength of the adhesive joints of plasma-treated polymers, such as polypropylene, by combining several surface characterization methods. Other tasks are related to the plasma activation of hybrid polymer composites and hydrogels.
Research areas
- Plasma processing of materials and biointerphases
- Inorganic and hybrid (organic/inorganic) coatings and nanomaterials
- Synthesis of carbon nanomaterials and their functionalization
- Advanced characterization of thin films and surfaces
Main objectives
- Develop plasma and microwave-based processes offering environmentally friendly and unique pathways for the material synthesis and modification.
- Understand the interaction of low-temperature plasma with surfaces, especially in plasma polymerization and plasma-based atomic layer processes, for improved tunability and selectivity.
- Develop atmospheric pressure plasma sources breaking the vacuum technology limitations.
- Demonstrate the power of nanotechnologies by synthesis of functional nanomaterials (carbon nanotubes or nanowalls, graphene, modified polymer nanofibers, metal-based nanoparticles).
- Prepare novel biomaterials and biointerphases for biosensors, tissue engineering, wound healing, antimicrobial effects and theranostics purposes.
- Prepare functional surfaces and interfaces with enhanced sensing properties, match-made surface free energy, or extremely large surface-to-volume ratio.
- Develop methodology and standardization of the scanning probe microscopy (SPM) data analysis using the open-source software, Gwyddion.
Group members
David Nečas, Ph.D.
Lucie Janů, Ph.D.
Marek Eliáš, Ph.D.
Kateřina Polášková, Ph.D.
Nima Bolouki, Ph.D.
Ph.D. students
Martina Janůšová
Nada Souawda
Aniket Mukherjee
Noor Mohamad
Beáta Beliančínová