Chemical bonding of perfluoropolyether with carbon underlying layer induced by visible laser light

• Published in: Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films Surfaces, and Films, 2003-07, Vol.21 (4), p.1087-1091
• Main Authors: Zhu, Lei, Zhang, J., Liew, T., Ye, K. D.
• Format: Article
• Language: English
• ISSN: 0734-2101; 1520-8559
• DOI: 10.1116/1.1568745

We investigated the chemical bonding of perfluoropolyether lubricant molecules with carbon overcoat surface by irradiating with a visible pulsed laser light. A Nd:yttrium–aluminum–garnet laser with a wavelength of 532 nm was used to irradiate the lubricant film (1–2 nm) on carbon overcoat surface in ambient environment. The bonding formed was characterized at the molecular level using the time-of-flight secondary ion mass spectroscopy. We found that with increasing laser fluence, the ion yield of the end group CF 2 CH 2 OH of the lubricant decreases which can be an indication of chemical bond formation of the end group with the active sites of the carbon underlying layer. X-ray photoelectron spectroscopy reveals more lubricant on the laser-irradiated area than the surrounding nonirradiated area after washing off nonbonded lubricant by solvent Vertrel XF, which has little effect on bonded lubricant. Furthermore, we propose a method to quantify the bonding/nonbonding ratio of lubricant by considering the end-group intensity versus its neighboring fluorocarbon fragments.