Plasma-enhanced fluorination

Surface modification in plasma-enhanced fluorination (PEF) conditions... 

A. Tressaud, E. Durand, C. Labrugere, Plasma-Enhanced Fluorination of Nitrile Butadiene... 

In addition to plasma-enhanced CVD reactors that we will study in this text, there is another important commercial application for low-pressure plasmas in "dry" etching.8 Here, a plasma converts an inert gas (i.e., from -CF4) to a mixture including free fluorine, which can then etch Si, Si02, etc. There are two advantages. One, the starting gas is inert and, two, anisotropic etching is possible due to ion bombardment. 

The functionalization of CNTs through plasma treatment represents a novel and easy approach to scale up towards industrial applications. In more recent works, there were many attempts to fluorinate CNT sidewalls in such manner. The CF4 plasma treatment of SWNT sidewalls was demonstrated to enhance the reactivity of tubes with aliphatic amines.The cure reaction of diglycidyl ether of bisphenol A-based epoxy resin (DGEBA), when reacted with butylamine molecules (BAMs) anchored on to the plasma treated fluorinated SWNTs, was reported. The advantage of this method was that the functionalization could be achieved through a simple approach, which is widely used in thin film technologies. As covalently modified CNTs with fluorine groups offer the opportunity for chemical interactions with the amine systems, it was recently demonstrated that this... 

In surface fluorination with vacuum ultraviolet glow discharge plasma, the photon component of the plasma enhances the reactivity of the polymer surfaces toward fluorine gas " ... 

Corbin, G.A., Cohen, R.E. and Baddour, R.F., Kinetics of Polymer Surface Fluorination Elemental and Plasma Enhanced Reactions , Polymer, 23, 1546-1548 (1982)... 

Ahmed, M.H., Byrne, J.A., Mclaughlin, J., 2012. Evaluation of glycine adsorption on diamond like carbon (DLC) and fluorinated DLC deposited by plasma-enhanced chemical vapour deposition (PECVD). Surf. Coat. Technol. 209, 8—14. http //dx.doi.org/10.1016/ j. surfcoat2012.07.011. 

Taschner, C. Leonhardt, A. Schonherr, M. Wolf, E. Henke, J. (1991). Structure and Properties of TiC Layers Prepared by Plasma-Assisted Chemical Vapour Deposition Methods. Mater, Sci Eng, A, Vol. 139, pp. 67-70 Thery, J. Martin, S. Faucheux, V. Le Van Jodin, L. Truffier-Boutry, D. Martinent, A. Laurent, J.Y. (2010). Fluorinated Carboxylic Membranes Deposited by Plasma Enhanced Chemical Vapour deposition for Fuel Cell Applications. /, Power Sources, Vol. 195, pp. 5573-5580... 

Although there are several reports for the synthesis and adsorption studies in FMOFs, depending on the structural arrangements, FMOFs can be divided into three parts (i) anion-induced fluorination in MOFs (ii) MOFs constructed by fluorinated ligands and (iii) fluorination in MOFs via plasma-enhanced chemical vapor deposition (PECVD). 

The fluorination of the inner surface of intravenous tubing, using atmospheric pressure plasma glow (APG), has been evaluated to enhance biocompatibility and suppress plasticiser migration (273). The effect of plasma treatment on the migration of DOA, and an EVA-carbon monoxide terpolymer as partial or complete replacement, into isooctane solution has given positive results (231). A closed system microwave plasma reactor was used to react imidazole molecules to PVC surfaces with the claim that the resulting PVC was useful as an implant for biomedical applications, on the basis of spectroscopic studies (368). 

It has been found, however, that the etch rate of PBS can be reasonably controlled in both oxygen and CF4/O2 plasmas if the substrate temperature is kept below room temperature (9). This fact has been utilized to reduce the defect density in the manufacture of chrome photomasks by exposing the developed PBS pattern to a low-temperature oxygen plasma (descum) prior to wet-etching the chrome. We have now found that the plasma-etch resistance of PBS in a CF4/O2 plasma can be markedly enhanced at room temperature simply by exposing the resist to a short oxygen plasma pretreatment prior to exposure to the fluorinated plasma. This effect can be used in a variety of pattern transfer processes to controllably generate submicron features on wafers and masks. This paper examines the parameters associated with this effect, proposes a mechanism to account for the results and delineates some possible pattern transfer processes. 

Most of these discussions regarding fluorine contamination of aluminum surfaces have focused on the conversion of aluminum oxide to fluoride or oxyfluoride. Evidence for similar conversions was included, and in extreme cases conversion to aluminum bonding quite similar to that in AIF3 was found. However, the poor adhesion of the samples skipping the O2 plasma treatment is related not to the fluorine contamination as such, but rather to the carbonaceous nature of the adsorbed materials, which is subjected to the plasma polymerization of TMS. Oxygen plasma cleaning removes this carbonaceous component, while the surface fluorine concentration is enhanced. 

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