Experimental and Theoretical Study of the Effect of the Inductive-to-Capacitive Transition in Propanethiol Plasma Polymer Chemistry

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• 作者：Damien Thiry ; Nikolay Britun ; Stephanos Konstantinidis ; Jean-Pierre Dauchot ; Maxime Guillaume ; J茅r么me Cornil ; Rony Snyders
• 刊名：The Journal of Physical Chemistry C
• 出版年：2013
• 出版时间：May 16, 2013
• 年：2013
• 卷：117
• 期：19
• 页码：9843-9851
• 全文大小：415K
• 年卷期：v.117,no.19(May 16, 2013)
• ISSN：1932-7455

文摘

The influence of the capacitive (E)-to-inductive transition (H) in inductively coupled plasma discharges is investigated for propanethiol plasma polymerization. In the E mode, at low plasma density, the sulfur content in the layers, measured by XPS, is quite high and strongly decreases after aging in the air. This phenomenon is attributed to the desorption of trapped sulfur-based molecules (e.g., H₂S). In the H mode, presumably higher surface temperature prevents the trapping scenario during the layer growth and, as a consequence, yields a lower sulfur content which is stable after aging. Mass spectrometry measurements reveal important variations of the plasma chemistry depending on the discharge mode. The major change concerns the complete disappearance of the precursor in the H mode accompanied by the large production of CS₂ molecules. Furthermore, a linear correlation is found between the concentration of the CS₂ species and the atomic sulfur content in the H-mode synthesized layers. In addition, based on DFT calculations, different pathways of fragmentation are proposed as a function of the plasma parameters. The whole set of results highlight the importance of the E鈥揌 transition for the growth of thiol-based plasma polymers.