Growth of self-assembled monolayer on tetrahedral amorphous carbon film coated magnetic head

The magnetic heads overcoated by tetrahedral amorphous carbon (ta-C) films have been immersed in the 1H, 1H, 2H, 2H-perfluorodecyltrichlorosilane (FDTS) solvent at different predetermined dipping time. The growth of FDTS self-assembled monolayer (SAM) on the ta-C surface has been confirmed by time-of-flight secondary ion mass spectrometry. Four distinct stages were observed in the growing process: (1) low coverage (nucleation), (2) growing up (3) coalescence and (4) complete monolayer, similar to the theoretical models of epitaxial film growth at low temperatures. Contact angle measurement using de-ionized water is carried out to study the time dependence of contact angle during the growth process of FDTS monolayer. The surface morphology, profiles and roughness (rms) of FDTS monolayer were determined by atomic force microscopy (AFM). Furthermore, the variation of monolayer thickness and distribution was revealed by transmission electron microscopy, which is in agreement with the AFM and contact angle results.