In plasma assisted thin film growth, control over the energy and direction of the incoming species is desired. If the growth species are ionized this can be achieved by the use of a substrate bias or a magnetic field. Ions may be accelerated by an applied potential, whereas neutral particles may not. Thin films grown by ionized physical vapor deposition (I-PVD) have lately shown promising results regarding film structure and adhesion. High power impulse magnetron sputtering (HIPIMS) is a relatively newly developed technique, which relies on the creation of a dense plasma in front of the sputtering target to produce a large fraction of ions of the sputtered material. In HIPIMS, high power pulses with a length of ~100 μs are applied to a conventional planar magnetron. The highly energetic nature of the discharge, which involves power densities of several kW/cm2, creates a dense plasma in front of the target, which allows for a large fraction of the sputtered material to be ionized. The work presented in this thesis involves plasma analysis using electrostatic probes, optical emission spectroscopy (OES), magnetic probes, energy resolved mass spectrometry, and other fundamental observation techniques. These techniques used together are powerful plasma analysis tools, and used together give a good overview of the plasma properties is achieved. from the erosion zone of the magnetron. The peak plasma density during the active cycle of the discharge exceeds 1019 electrons/m3. The expanding plasma is reflected by the chamber wall back into the center part of the chamber, resulting in a second density peak several hundreds of μs after the pulse is turned off. Optical emission spectroscopy (OES) measurements of the plasma indicate that the degree of ionization of sputtered Ti is very high, over 90 % in the peak of the pulse. Even at relatively low applied target power (~200 W/cm2 peak power) the recorded spectrum is totally dominated by radiation from ions. The recorded HIPIMS spectra were compared to a spectrum taken from a DC magnetron discharge, showing a completely different appearance. Magnetic field measurements performed with a coil type probe show significant deformation in the magnetic field of the magnetrons during the pulse. Spatially resolved measurements show evidence of a dense azimuthally E×B drifting current. Circulating currents mainly flow within 2 away cm from the target surface in an early part of the pulse, to later diffuse axially into the chamber and decrease in intensity. We record peak current densities of the E×B drift to be of the order of 105 A/m2. A mass spectrometry (MS) study of the plasma reveals that the HIPIMS discharge contains a larger fraction of highly energetic ions as compared to the continuous DC discharge. Especially ions of the target material are more energetic. Time resolved studies show broad distributions of ion energies in the early stage of the discharge, which quickly narrows down after pulse switch-off. Ti ions with energies up to 100 eV are detected. The time average plasma contains mainly low energy Ar ions, but during the active phase of the discharge, the plasma is highly metallic. Shortly after pulse switch-on, the peak value of the Ti1+/Ar1+ ratio is over 2. The HIPIMS discharge also contains a significant amount of doubly charged ions.

In this thesis, we focused on the understanding of the synthesis and texturization processes of hydrophobic and (super)hydrophobic fluorinated surfaces by atmospheric plasmas.<p><p>First, we focused on the surface modifications of a model surface, the polytetrafluoroethylene (PTFE), by the post-discharge of a radio-frequency plasma torch. The post-discharge used for the surface treatment was characterized by optical emission spectroscopy (OES) and mass spectrometry (MS) as a function of the gap (torch-sample distance), and the helium and oxygen flow rates. Mechanisms explaining the production and the consumption of the identified species (N2, N2+, He, O, OH, O2m, O2+, Hem) were proposed. <p><p>The surface treatment was then investigated as a function of the kinematic parameters (from the motion robot connected to the plasma torch) and the gas flow rates. Although no change in the surface composition was recorded, oxygen is required to increase the hydrophobicity of the PTFE by increasing its roughness, while a pure helium plasma leads to a smoothing of the surface. Based on complementary experiments focused on mass losses, wettability and topography measurements coupled to the detection of fluorinated species on an aluminium foil by XPS, we highlighted an anisotropic etching oriented vertically in depth as a function of the number of scans (associated to the treatment time). Atomic oxygen is assumed to be the species responsible for the preferential etching of the amorphous phase leading to the rough surface, while the highly energetic helium metastables and/or VUV are supposed to induce the higher mass loss recorded in a pure helium plasma.<p><p>The second part of this thesis was dedicated to the deposition and the texturization of fluorinated coatings in the dielectric barrier discharge (DBD). The effects of the nature of the precursor (C6F12 and C6F14), the nature of the carrier gas (argon and helium), the plasma power, and the precursor flow rate were investigated in terms of chemical composition, wettability, topography and crystallinity by SIMS, XPS, WCA, AFM and XRD. We showed that hydrophobic surfaces with water contact angles (WCA) higher than 115° were obtained only in the presence of argon and were assumed to be due to the roughness created by the micro-discharges. Plasma-polymerized films in helium were smooth and no WCA higher than 115° was observed. We also studied the impact of the deposition rate and the layer thickness in the hydrophobic properties as well as the polymerization processes through the gas phase characterization.<p> / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

Táto práca sa zaoberá prenosom analytických modelov medzi rôznymi systémami spektroskopie laserom indukovanej plazmy (LIBS) a porovnaním LIBS výsledkov získaných na rôznych systémoch. Instrumentácia LIBS aj spracovanie LIBS spektier sú vysoko flexibilné. Bohužiaľ, kvôli týmto flexibilitám sú výsledky získané na jednom LIBS systéme zriedka priamo porovnateľné s výsledkami získanými na inom systéme. Toto je ďalej komplikované rôznymi, často neznámymi, účinkami algoritmov spracovania LIBS spektier. V dôsledku toho sú modely analýzy spravidla špecifické pre systém (a parametre). Prenos analytických modelov medzi rôznými systémami by viedol k významnému zlepšeniu analytických schopností metódy LIBS a k miernemu zníženiu nákladov v priemyselných aplikáciách LIBS. Práca skúma vplyv rôznych stratégií merania metódou LIBS. Naďalej, práca skúma transformáciu získaných LIBS spektier prostredníctvom spracovávania údajov. Práca sa napokon zaoberá prenosom analytických modelov medzi rôznymi LIBS systémami.