Investigation of the formation mechanism of the fluorocarbon film in CF4 plasma processing of fused silica

Surface Modification of a Regenerated Cellulose Film Using Low-Pressure Plasma Treatment with Various Reactive Gases

“…However, a decrease in the contact angle for the RC films treated with N 2 plasma is less obvious as compared to O 2 plasma, suggesting that the reaction and grafting of oxygenated species lead to lower WCA than the formation of nitrogen species . In contrast to the O 2 and N 2 plasma treatments, CF 4 plasma changes the surface of the RC film to the hydrophobic and contact angle reached a maximum of 120.6° in a short irradiation time of 60 s. A rapid change to the hydrophobic surface may be caused by the fact that CF 4 plasma can make the surface rougher via etching by ions and functionalize the surface of the RC film with hydrophobic fluorine functional groups . However, interestingly, as the plasma exposure time was further increased, the contact angle decreased, and the surface of the RC film returned to hydrophilic, indicating that the chemical bond between fluorine and cellulose was saturated and the number of defects increased .…”

“…29 In contrast to the O 2 and N 2 plasma treatments, CF 4 plasma changes the surface of the RC film to the hydrophobic and contact angle reached a maximum of 120.6°in a short irradiation time of 60 s. A rapid change to the hydrophobic surface may be caused by the fact that CF 4 plasma can make the surface rougher via etching by ions and functionalize the surface of the RC film with hydrophobic fluorine functional groups. 30 However, interestingly, as the plasma exposure time was further increased, the contact angle decreased, and the surface of the RC film returned to hydrophilic, indicating that the chemical bond between fluorine and cellulose was saturated and the number of defects increased. 31 Furthermore, WCA of RC films left under ambient conditions for 1 month after plasma modification was also measured to investigate the durability of surface wettability induced by each plasma treatment.…”

Model-Based XPS Technique for Characterization of Surface Composition on Nano-Scale SiCOH Sidewalls

“…The reduced carbon content suggests that, with this particular etch chemistry, the polymerizing fluorocarbon layer on the sidewall is thinner than on the horizontal surfaces. As the etch chemistry contains a high flow rate of reactive fluorine atoms, primarily due to the elevated CF4 flow rate, 10 the Fluorocarbon layer on the sidewalls exhibits a higher fluorine concentration, particularly because they remain undisturbed by ion bombardment. The application of high bias power is expected to result in more anisotropic ion behavior, leading to increased surface damage on the horizontal surfaces compared to the sidewalls.…”

Improved the laser-induced damage threshold of fused silica by atmospheric pressure plasma processing

“…In the past decades, much research has been done on the deterioration of the surface morphology of fused silica processed by atmospheric pressure plasma. Jin [7] proposed that the deteriorated surface morphology caused by fluorocarbon films deposited during the atmospheric plasma etching process, and the addition of O2 flow is proposed to inhibit the deposition of fluorocarbons. Jiang [8] suggested that due to the mismatch binding energy between the inhibitor particles and the substrate the inhibitor particles preferentially bond to each other and form large particles, which were deposited on the surface, resulting in the deterioration of surface topography.…”