Comparison of pulsed and downstream deposition of fluorocarbon materials from C3F8 and c-C4F8 plasmas

Abstract

Studies of fluorocarbon film deposition and its correlation with etched trench sidewall angle by employing a gap structure using C 4 F 8 ∕ Ar and C F 4 ∕ H 2 based capacitively coupled plasmas Comparison of plasma chemistries and structure-property relationships of fluorocarbon films deposited from octafluorocyclobutane and pentafluoroethane monomers Materials deposited in continuous wave ͑cw͒ and pulsed low-pressure octafluoropropane (C 3 F 8 ) and octafluorocyclobutane (c-C 4 F 8 ) plasmas were characterized using Fourier transform infrared spectroscopy ͑FTIR͒, x-ray photoelectron spectroscopy, static contact angle measurements, spectroscopic ellipsometry, and scanning electron microscopy ͑SEM͒. Fluorocarbon ͑FC͒ materials deposited in pulsed plasmas were less crosslinked than those deposited in cw plasmas with equivalent input powers. Within each system, higher F/C ratio materials were deposited by lowering the plasma input power/duty cycle. Using downstream depositions had a similar effect on film composition, but also resulted in decreased deposition rates. SEM analysis showed that decreases in the flexibility of the fluorocarbon films were correlated with increases in the percent of crosslinking. Additionally, the smoothness of the film surfaces suggests that polymerization processes occur on the substrate surface. Overall, films deposited in C 4 F 8 plasmas were more crosslinked and less flexible than those deposited in C 3 F 8 plasmas under the same conditions. The composition of the deposited FC films is correlated to the nature and relative concentrations of nascent ions previously measured in these plasma systems using plasma ion mass spectrometry.

Plasma enhanced CVD of fluorocarbon films by low-pressure dielectric barrier discharge

“…Deposition of long CF 2 chains may result in a FC film with significant CF 2 content. It is generally assumed that the constant exposure to energetic ions typically leads to deposition of more brittle FC films with crosslinked structure [22,24,25]. Decreasing deposition pressure may lead to a rapid increase in the breakdown voltage [27].…”

Conformal Encapsulation of Three-Dimensional, Bioresorbable Polymeric Scaffolds Using Plasma-Enhanced Chemical Vapor Deposition

“…Spectra for C 3 F 8 plasma treated scaffolds contain more C 1s binding environments than those found in the spectra of untreated scaffolds, indicative of an array of FC binding environments. Based on previous C 3 F 8 PECVD studies, the CF 2 contribution (292.0 eV) should dominate over other FC binding environments, 30,31 which is indeed seen in spectra of the scaffold tops, regardless of treatment time, and on scaffold cross sections for all but the 5 min C 3 F 8 treatment. In all spectra, additional peaks can be attributed to CF x moieties such as −CF, −CF 3 , and −C−CF x .…”

Osteoblast-Like Cell Behavior on Plasma Deposited Micro/Nanopatterned Coatings

“…Plasma deposition processes fed with fluorocarbon gases, especially when run in modulated power regime or in afterglow, can provide the deposition of Teflon-like and rough coatings, characterized by different topographical features like ribbons or bumps, [22][23][24] able to successfully tune the cell response. 25,26 The deposition mechanism of such micro/nanostructured coatings was discussed by Milella et al 27 We have previously deposited fluorocarbon thin films by plasma enhanced chemical vapor deposition (PECVD) fed with hexafluoropropylene oxide (C 3 F 6 O).…”