Effect of Sputtering Temperature on Fluorocarbon Films: Surface Nanostructure and Fluorine/Carbon Ratio.

Qi Zhao,Guibai Xie,Feipeng Wang,Kaizheng Wang,Jian Li,Wanzhao Cui

doi:10.3390/nano9060848

Qi Zhao, Guibai Xie + Show 4 more

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https://doi.org/10.3390/nano9060848

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Abstract

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.

Highlights

Fluorocarbon film, due to its superior hydrophobicity, low dielectric constant and small friction coefficient, is a promising material in various fields [1,2,3]
The surface roughness and chemical composition of fluorocarbon films are considered to have a critical influence on the water contact angle (WCA) [40]
According to the Cassie model, the WCA of a rough surface is a composite contact angle between water and the compound surface made of fluorocarbon film and air

Summary

Introduction

Fluorocarbon film, due to its superior hydrophobicity, low dielectric constant and small friction coefficient, is a promising material in various fields (e.g., self-cleaning coatings for perovskite solar cells, interlayer dielectrics in integrated circuits and lubricant coatings in micro-machines) [1,2,3]. The deposition of fluorocarbon films is controlled by various factors, including sputtering type [12,13,14], target material [15,16] and substrate temperature [17,18]—all of which govern the modulus, hardness and wettability by adjusting the elemental composition and surface morphology. (tee.mg.p, eCr–aCtuarend(FCig–uCrFe),4t)h.eAinscrleaargseedr afrtaogmmicenctosnceexnhtirbaittioanshoigfhlaerrgsetricfkrainggmecnotesffhiceilepnttothinacnresamseatlhleer sftriacgkminegnctose(ffie.cgi.e,nCt –oCf flaunodrocCa–rCboFn),fitlhmesi[n2c9r]e.aMseodreaotvoemr,itchecoenlecveantterdatsiuonbsstroaftelatregmepr efrraatgumreeinstbsehneelfipcitaol fionrcrfleuaoseroctharebosnticfiklimngdecnoseiffifcicaiteionnt boyf efnluhoarnoccinargbtohne rfeil-mcosnd[e2n9]s.atMionorperoovceers,s tohfeejeecletevdatferdagmsuebnsttsraotne temperature is beneficial for fluorocarbon film densification by enhancing the re-condensation process of ejected fragments on the substrate [38]. At 2t0200◦0C°,Ct,htehbeobttootmtosmosf tohfethcleusctleursstecrosncnoenctneedctwedithweiathcheoatchheor tahnedr tahnedtotphoef tthoapt gorfewthvaetrtgicraelwly, lveeardtiicnaglltyo,thleeandeitnwgortkosttrhuectnueretwfoorrmkatsitornucotfugrreanfuorlamr afltuioonrocoafrbgornanfiulmlasr. fluorocarbon films

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Bond disorder

Conclusions