A lot of kinds of reactive chemical species generated in plasma contribute to the film deposition, so that the films can be deposited at low temperatures and many types of films can be deposited. Controlling Plasma-induces Surface Reactions will be the key of the future film deposition, as well as the control of plasma. State-of-art studies in this field will be introduced.

We overview plasma-enhanced chemical vaper deposition (PECVD) of high-quality thin-film silicon. In PECVD, such a film is grown by the deposition of precursors, which is generated by the gas-phase reactions of source gases in plasma. The growth of the film depends on the surface reactions of precursors and the reactions in the growing film, i.e., in-film reactions, which influences the film structure and properties. The in-film reactions also take place after the growth, i.e., post-growth annealing. So, the reactions should be properly controlled throughout the growth and annealing for the high-quality film formation. Here, the growth kinetics and related reactions are presented for device-grade hydrogenated amorphous silicon (a-Si:H) films.

In this paper, we focus on the performance improvement of diamond-like carbon (DLC) by adding Si atoms, and summarize the conventional research developments centered on the friction application of Si-containing DLC (Si-DLC) thin films. In addition, we introduce new research and application development of Si-DLC in recent years. After recognizing and sharing the importance of Si incorporation into the Si-DLC thin films, we also introduce the mass spectrometric measurements of Si-containing hydrocarbon ions and radicals in tetramethylsilane plasmas for the purpose of understanding the plasma used for the synthesis of Si-DLC thin films.

A new plasma-enhanced chemical vapor deposition (PECVD) system using photo-excited plasma, photoemission-assisted PECVD (PA-PECVD), is explained. PA-PECVD gives certain voltage and current density during its plasma reactions, controlling plasma reactions precisely. The voltage is a thermodynamic factor to determine how a chemical reaction occurs. The current density is a kinetics factor to determine how fast the reaction occurs. Its Townsend discharge, photoemission-assisted Townsend discharge (PATD), gives current approximately 10000 times larger than conventional Townsend discharge. PATD can be used for precise deposition of diamond-like carbon (DLC) films without damage by accelerated ions and the films can be optimized for carbon electronics. Investigation of the characteristics of the DLC films precisely synthesized by PA-PECVD leads to elucidate its growth model and will contribute to the tailor-made synthesis of DLC suitable to every industrial purpose.

With the sophistication of various surface processes by non-equilibrium plasma in the gas phase, it is a certain necessity in the direction of scientific and technological development to incorporate extended reaction fields due to the non-equilibrium nature of solid plasma and to design integrated non-equilibrium reaction fields. In this paper, we introduce the plasmon resonance of nanoparticles on silicon wafers and chemical reactions on the surface layer enabled by radicals supplied by plasma. Plasma deposition can be performed at room temperature using plasmon resonance of nanoparticles on Si substrates. The case using gold nanoparticles and the case using HfN nanoparticles are shown.

Mechanism of the functional thin film fabrication method using powders target has been studied. Experimental results suggest that functional thin film can be fabricated, and it is possible to fabricate elementally controlled thin films. The reaction at the substrate surface with the plasma near the substrate is almost the same as in the normal sputtering deposition process. However, it was clarified that the reaction at the interface between the target surface and the plasma has different characteristics from the usual sputtering deposition mechanism. For example, it was suggested that the deposition rate, etc., near the target differs due to the different surface structure of the ion incident area.

A novel synthesis method of nanographene materials by using in-liquid plasma has been developed. By this method, the high synthesis rate of nanographene up to 1 mg/min. can be realized. There is a trade-off relationship between synthesis rate and crystallographic domain size with respect to the number of carbon atoms in the raw alcohol molecules. For example, when using 1-butanol (C₄H₉OH), the synthesis rate is approximately twice as high as when using ethanol (C₂H₅OH), but the domain size, which indicates crystallographic quality, is about half smaller. On the other hand, when using hexane (C₆H₁₄) or benzene (C₆H₆), the synthesis rate is approximately 17 times and 1.7 times faster than when using hexanol (C₆H₁₃OH), respectively, but their domain size is much smaller compared with that by ethanol. This indicates an effect of OH radicals on the domain size improvement. By adding iron (II) phthalocyanine, etc. to the alcohol raw material, nitrogen-doped nanographene materials were successfully synthesized and confirmed their catalytic activity. The mechanism of expression of catalytic activity was also clarified.