Plasma Processes and Polymers

Cover: A section of a-SiC:H multilayer film consisting of polymer-like bilayers has been investigated using atomic force microscopy, atomic force acoustic microscopy (AFAM), and nanoindentation. The picture shows well-distinguished individual layers and the Young's modulus and hardness determined for each layer using nanoindentation measurements. Further details can be found in the article by V. Cech,* R. Trivedi, and D. Skoda on page 1107.

Hematoxylin and eosin-stained histological sections of tissue cut using (a) Ar and (b) Ar/CCl₄plasmas, demonstrating tissue removal enhancement from the chosen reactive plasma chemistry. The chemical composition of plasma with haloalkane feedstock was determined using optical emission spectroscopy.

Multilayer film was sectioned at a shallow angle to reveal the individual layers. These were investigated by semicontact AFM (topography, error and phase imaging mode), contact AFM (lateral force mode and atomic force acoustic microscopy (AFAM)), and nanoindentation to determine the Young's modulus and hardness for each individual layer.

Use of a laser diffraction technique to measure precursor droplets size and solid particles size distributions in an atmospheric plasma reactor shown on the picture below. The change in droplet size with time is studied in presence or absence of plasma. The formation of solid particle in presence of plasma is also examined.

Synthesis of a-SiCN:H films via atmospheric pressure plasma enhanced CVD (AP-PECVD) using triethylsilane (HSiEt₃) and nitrogen plasma is discussed in this article. The role of reactive gas (N₂), precursor chemistry (HSiEt₃) and substrate temperature on the film's physical and chemical properties are investigated. A possible chemical route based on the experimental observations is proposed.

Low-pressure, inductively coupled plasma sustained in an Ar/O₂/N₂ternary mixture is studied in this contribution in order to find out a relation between working gas mixture composition and properties of such plasma relevant for sterilization and decontamination of surfaces.

This paper describes the spectroscopic characterization of plasmas generated by ECR discharge of N₂gas and pulsed laser ablation of B₄C. The interactions between the PLA boron/carbon plasma and the ECR nitrogen plasma during the expansion of the PLA plasma in the ECR plasma are studied. The mechanisms for the high reactivity of the plasmas and the processes including gas-phase reactions occurring in the plasmas are discussed based on the results of OES measurements.

Non-thermal plasma has been used to coagulate blood, induce apoptosis and enhance angiogenesis. We studied which reactive oxygen species produced by dielectric barrier discharge plasma promote angiogenesis via fibroblast growth factor-2 release. H₂O₂, OH^•, O, and O₂(¹Δ_g) were measured in plasma-treated liquid and cells. Specific probes and inhibitors showed that H₂O₂ and OH^• are the primary species responsible for plasma-induced angiogenesis.

Thin, transparent PTFE-like coatings with a remarkably high amount of CF₂-groups to the extent of 85% were deposited with a pulsed microwave discharge. They were obtained by PECVD using solely C₃F₈ as precursor. The influence of gas pressure and microwave power on properties of the deposited coatings like content of CF₂-chains, F/C-ratio, deposition rate and wettability is described.

Thermoplastic vulcanizate (TPV) substrates were coated with thin TiN films, aiming to develop polymer-based electrodes for bio-signal acquisition, namely electroencephalographic and electrocardiographic applications. A detailed experimental protocol was followed in order to improve the adhesion of the film, consisting of a three-stage plasma treatment. The electrochemical properties of the coated samples were studied in synthetic sweat solutions.

HBr plasma treatment shows great capabilities to decrease the sidewalls roughness of photoresist pattern printed by 193 nm lithography. The VUV light emitted by HBr plasmas plays a major role in the resist surface smoothening. However, the synergy between Bromine radicals and VUV light leads to the formation of dense graphitized layers on all resist pattern surfaces that strengthen the resist pattern but lead to increased surface roughness compared to VUV light treatment.