Plasma-assisted chemistry

Pollution control such as the reduction of nitrogen oxides, halocarbons and hydrocarbons from flue gases [37] is another important field of plasma-assisted chemistry using non-thennal plasmas. The efficiency of plasma chemical reactions can be enhanced by introducing catalysts into the plasma [38, 39]. 

While the present discussion on non-thermal chemical reactions induced by the direct specific action of sub-THz radiation is ongoing, it is well known that non-thermal reactions can also be initiated indirectly via plasmas generated by the same radiation. In fact, plasma-assisted chemistry is strongly related to the field of polymers, and its importance and major potential for industrial applications are described in the following subsections. 

The great interest in the field of plasma-assisted chemistry is reflected by a large number of reviews and books [45,46,48-62], and by two journals devoted to the subject [63,64]. 

Xu, W., et ah, Low-temperature plasma-assisted preparation of graphene supported palladium nanoparticles with high hydrodesulfurization activity. Journal of Materials Chemistry, 2012. 22(29) p. 14363-14368. 

Recognition of TiN as a supreb barrier to diffusional and electrical activity has resulted in extensive research on the CVD of TiN for microelectronic layers. Significant advances have been made in the area of plasma-assisted CVD where dc glow , ECR , and helicon plasmas have all been used. Implementation of such plasmas can reduce the processing temperature of reaction (b) to 400°C. For plasma deposition of TiN using titanium isopropoxide, the deposition temperature can be as low as 100°C, where the chemistry is outlined as follows ... 

Plasmas are also used for the low temperature deposition of thin solid films, for example amorphous hydrogenated silicon, diamond, and a host of other materials. Since the fundamentals of plasma physics and chemistry are the same for both plasma etching and plasma assisted chemical vapor deposition (PECVD), the latter will only be discussed briefly in Section 6.6. A review of PECVD can be foxmd in [14]. Sputtering is discussed by Chapman [15], and plasma polymerization is covered by Yasuda [16]. 

All three processes can occur simultaneously when a surface is exposed to a plasma. The relative importance of one mechanism over the others depends on the material system (surface and gas), the ratio of neutral to ion flux, and the ion energy. In general, conditions are selected such that ion assisted chemistry dominates. In cases that chemical etching dominates, a mechanism for wall passivation (Section... 

In the final chapter of this volume on fiuidamentals of plasma chemistry, we would like to point out future opportunities for the atomic, molecular, and optical (AMO) physics community to contribute to a better microscopic understanding of the plasma-chemical processes in various plasma-assisted materials-processing applications as well as in other applications. We will address both gas-phase (volume) processes and plasma-surface/wall processes. We will fiirther attempt to identify some of the important challenges for the AMO physics community. By opportunities we mean problems that can be addressed through the application of established AMO physics methods and techniques, and by challenges we mean problems where the development and application of new AMO physics methods, methodologies, and techniques will be needed. 

Magureanu, M. (2012) VOC removal from air by plasma-assisted catalysis-experimental work, in Plasma Chemistry and Catalysis in Gases and Liquids (eds V.I. Parvulescu, M. Magiu-eanu, and P. Lukes), Wiley-VCH Verlag GmbFl, Weinheim, pp. 131-170. 

Coburn J W and Winters H F 1979 Ion- and electron-assisted gas-surface chemistry—an important effect in plasma etching J. Appl. Phys. 50 3189-96... 

---