Composite plasma polymer films prepared by RF magnetron sputtering of SiO2 and polyimide
Introduction
Composite films comprising a metal and plasma polymer have been investigated for several decades (For a review, see Refs. [1], [2], [3]). However, later the interest moved on to more complex composites such as the plasma polymer. These composite films were prepared by ion beam co-sputtering [4] and by plasma polymerization [5], [6] with the idea to apply them as protective coatings. The above-mentioned composite films were also deposited using an RF magnetron equipped with a composite SiO2/polytetrafluoroethylene (PTFE) target [7]. Recently, these films have been sputtered from two magnetrons equipped with PTFE and SiO2 targets, respectively [8]. At the same time composite films of plasma polymer, or, a-C:H prepared by plasma polymerization of hexamethyldisiloxane (HMDSO) and a hydrocarbon were investigated [9], [10]. Similar films have also been prepared by RF co-sputtering from two magnetrons equipped with SiO2 and polyethylene or polypropylene targets [11].
Polyimide-like films have been at the centre of attention for some time because of the prospect of their application in microelectronics owing to their low dielectric constant, high thermal stability, or, excellent anti-corrosion and wear resistant properties. Maggioni [12] focused on the preparation of these films by glow discharge vapour deposition polymerization (GDVDP) and Kinbara [13] prepared polyimide-based organic thin films by RF magnetron sputtering in an N2/CF working gas mixture using a polyimide (Kapton) target. Also hybrid nanocomposite films of silica (SiO2) in polyimide (PI) from 4,4-hexafluoroisopropylidene diphthalic anhydride (6FDA), 2,2-Bis (3-amino-4-hydroxyphenyl) hexafluoropropane (6FHP) and nonlinear optical (NLO) molecules were successfully fabricated by an in situ sol–gel process [14]. They were proposed to be used for a number of photonics applications including a doubled-frequency laser source, electro-optic modulation, optical signal processing and optical inter-connects.
In our study, we used RF co-sputtering in argon from two balanced planar magnetrons equipped with SiO2 and PI targets, respectively. In the following, we will simply denote these as reflecting that PI was used as the source material of the hydrocarbon plasma polymer component. The deposition process and basic characterization of these composite films are described below.
Section snippets
Experimental
Composite films were prepared by simultaneous RF sputtering of silica and PI targets from the two balanced magnetrons using argon as the working gas at a pressure of 5 Pa and a flow rate (STP)/min (see Table 1). The deposition arrangement (Fig. 1) consisted of two planar balanced magnetrons (marked as and in Fig. 1), 78 mm in diameter, placed next to each other with their centres 90 mm apart. SiO2 and PI (Fig. 2) targets in shapes of disks (marked as SiO2 and PI, respectively), both
Contact angle measurements
The dependence of static contact angle of water on the ratio of applied powers to the magnetrons is shown in Fig. 3. A decrease in static contact angle from to is observed with an increase in the power ratio in the range from 0.1 to 6. The maximum contact angle is achieved at a higher concentration of pPI in the film at a power ratio of 0.1. The reported variation of a contact angle reflects changes in the amount of and hydrocarbon plasma polymer in the composite film.
Conclusions
Composite plasma polymer films prepared by radio frequency magnetron co-sputtering of PI and SiO2 possess a wide range of properties depending on the deposition parameters, in particular on the power ratio of the powers delivered to the targets. Wettability in terms of contact angle of water reveals that with the decrease of content in the composite films (equivalent filling factor decreases from about 0.7 to 0.1) the static contact angle of water is increased in
Acknowledgements
This work is a part of the research plan MSM 0021620834 that is financed by the Ministry of Education and Sports of the Czech Republic.
References (21)
- et al.
Plasma polymer—metal composite films
- et al.
Surf Coat Tech
(2002) - et al.
Surf Coat Technol
(1999) - et al.
Surf Coat Technol
(2001) - et al.
Thin Solid Films
(2003) - et al.
Eur Pol J
(2004) - et al.
Physica E
(2003) - et al.
Chem Phys Lett
(2003) - et al.
Plasma polymerization procesess
(1992) Plasma polymer films
(2004)
Cited by (33)
Convex vs concave surface nano-curvature of Ta<inf>2</inf>O<inf>5</inf> thin films for tailoring the osteoblast adhesion
2020, Surface and Coatings TechnologyCitation Excerpt :The approach seems to be feasible for different pairs of the materials because our earlier experiments with C:H particles and C:H capping layers produced similar results [26]. It is also worth noting that in our previous works, the mechanical mismatch between two components, even when present, has never led to the controllable disintegration of heterogeneous PECVD coatings because the formation of both components was not decoupled in time and space [38–41]. The wetting behavior of the surfaces was assessed by the static WCA measurements.
Self-organization of vapor-deposited polyolefins at the solid/vacuum interface
2020, Progress in Organic CoatingsCitation Excerpt :Surface patterning may induce the phase separation and structuring in blended homopolymer or copolymer thin films [7,8]. It is also known that certain polymer films can be fabricated by gas-phase methods [9–15]. In this case, involvement of the liquid phase is avoided and the polymer/polymer and polymer/substrate interactions can be studied while they are unperturbed by capillary effects.
Plasma-Induced Polymeric Coatings
2018, Non-Thermal Plasma Technology for Polymeric Materials: Applications in Composites, Nanostructured Materials, and Biomedical FieldsWear Resistance of TiN<inf>x</inf>/CF<inf>y</inf> Coatings Deposited by RF Magnetron Co-Sputtering
2015, Journal of Materials Science and TechnologyCitation Excerpt :In this study, to eliminate the defects in PTFE materials reinforced with fillers, TiNx/CFy wear resistant composite coatings were prepared by magnetron co-sputtering, where chemical bonds between the TiNx and CFy components were present. Investigations on magnetron co-sputtering to produce nanocomposite coatings have been primarily focused on composite materials containing inorganic SiOx components[20–24]. SiOx/fluorocarbon films were prepared by sputtering a composite SiO2/PTFE target[20].
Nanocomposite and nanostructured films with plasma polymer matrix
2012, Surface and Coatings TechnologyCitation Excerpt :Also composite SiOx/hydrocarbon plasma polymer films were later investigated. These films were prepared, e.g., by plasma polymerization of hexamethyldisiloxane (HMDSO) and a hydrocarbon gas [33,34] or by RF co-sputtering from two magnetrons equipped with SiO2 and a polymer target — polyethylene (PE), polypropylene (PP) [35] or polyimide (PI) [36]. The SiOx/hydrocarbon plasma polymer composite films prepared by simultaneous co-sputtering reveal, similarly to fluorocarbon composites, a wide range of properties which depend on the preparation conditions, primarily on the RF power delivered to the individual magnetrons.