In this work, fluorocarbon film was deposited on silicon (P/100) substrate using polytetrafluoroethylene (PTFE) as target material at elevated sputtering temperature. Field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) were employed to investigate the surface morphology as well as structural and chemical compositions of the deposited film. The surface energy, as well as the polar and dispersion components, were determined by water contact angle (WCA) measurement. The experimental results indicated that increasing sputtering temperature effectively led to higher deposition rate, surface roughness and WCA of the film. It was found that the elevated temperature contributed to increasing saturated components (e.g., C–F2 and C–F3) and decreasing unsaturated components (e.g., C–C and C–CF), thus enhancing the fluorine-to-carbon (F/C) ratio. The results are expected aid in tailoring the design of fluorocarbon films for physicochemical properties.
With the development of industrial civilization, advanced manufacturing technology has attracted widespread concern, including in the aerospace industry. In this paper, we report the applications of ultra-thin atomic layer deposition nanofilm in the advanced aerospace manufacturing industry, including aluminum anti-oxidation and secondary electron suppression, which are critical in high-power and miniaturization development. The compact and uniform aluminum oxide film, which is formed by thermal atomic layer deposition (ALD), can prevent the deep surface oxidation of aluminum during storage, avoiding the waste of material and energy in repetitive production. The total secondary electron yield of the C/TiN component nanofilm, deposited through plasma-enhanced atomic layer deposition, decreases 25% compared with an uncoated surface. The suppression of secondary electron emission is of great importance in solving the multipactor for high-power microwave components in space. Moreover, the controllable, ultra-thin uniform composite nanofilm can be deposited directly on the complex surface of devices without any transfer process, which is critical for many different applications. The ALD nanofilm shows potential for promoting system performance and resource consumption in the advanced aerospace manufacturing industry.
The gas desorption and secondary electron multiplication induced by electron bombardment tend to induce severe low-pressure discharge effects in space microwave device cavities. Nevertheless, few studies have focused on both secondary electron emission and electron-stimulated gas desorption (ESD). Although the suppression of secondary electrons by graphene was found to be better in our previous study, it is still unclear whether the surface modification of graphene, which brings about different interfacial states, can also be manifested in terms of ESD. The deep mechanism of gas desorption and secondary electron emission from this extremely thin two-dimensional material under electron bombardment still needs further investigation. Therefore, this paper investigates the mechanism of graphene modification on Cu metal surface on the gas release and secondary electron emission properties under electron bombardment. The surface states of graphene-modified Cu were characterized, and the ESD yield and secondary electron yield of Cu/GoCu were investigated using a self-researched platform and analyzed using molecular dynamics simulations and electron Monte Carlo simulations. The results of the study showed that the most released component on the Cu surface under the bombardment of electrons was H2O molecules, while the most released component on the GoCu surface was H2 molecules. The graphene-modified samples showed a significant suppression effect on the secondary electron yield and ESD only in the low-energy region below 400 eV. This study can provide a valuable reference for suppressing low-pressure discharge and multipactor phenomena in space microwave components.
About Me
Senior engineer, China Academy of Space Technology (Xi’an).
Senior engineer, China Academy of Space Technology (Xi’an).