Molecular structure of interfaces formed with plasma-polymerized silica-like primer films: Part I. Characterization of the primer/metal interface using infrared spectroscopy in SITU

Abstract

Reflection-absorption infrared (RAIR) spectroscopy was performed in situ on plasma polymerized silica-like films that were deposited onto metal substrates. Relatively thick films ( $ 8.0 nm) had infrared spectra that were typical of bulk amorphous silicon dioxide (a-SiO 2 ). When thinner films were analyzed ( $ 0.6 nm), other infrared bands emerged that were due to the formation of silicon suboxide at the interface. Infrared bands due to oxidation of the substrate during deposition were also observed. It was determined that during the initial stages of plasma deposition, metal atoms from the substrate migrated to the metal-oxide surface. This resulted in preferential oxidation of metal atoms with the formation of silicon suboxide at the film=metal interface. In addition, interfacial suboxide formation was shown to have a dependence upon the diffusivity of the metal substrate atoms through the surface oxide of the metal. As a result, more interfacial suboxide was observed to form for depositions on titanium substrates in comparison with depositions on aluminum substrates.

Molecular Structure of the Interphase Formed by Plasma-Polymerized Acetylene Films and Steel Substrates

“…A schematic drawing of the reactor interfaced to the FTIR spectrometer is shown in Figure 1. This reactor, which has been described more completely elsewhere [11], enabled RAIR spectra to be obtained using one reflection of the IR beam from the substrate at an angle of 82 while the sample was kept under vacuum or in an inert environment. All RAIR spectra were collected at a resolution of 4 cm À1 using a mercury-cadmium-telluride (MCT) detector.…”

Surface and Interface Modifications of Aluminum Thin Films on Silica Glass Substrate Using 157 nm F2 Laser for Selective Metallization

“…In general, it is known that Al-O-Si bonds can be easy formed and are also strong and durable as an adhesive chemical bond. [16][17][18] For instance, when a monolayer of SiO 2 was formed on Al the substrate, Al-O-Si bonds were directly observed through XPS analyses. 19) Therefore, in our cases, the Si-O bonds (6.5 eV) of silica glass or native oxide Si were photo- dissociated upon irradiation by the F 2 laser of high photon energy (7.9 eV), 20,21) and the Al-O-Si bonds might be formed, inducing the strong adhesion between Al and silica glass.…”