Fluorination of the silicon-terminated (100) diamond surface using C60F48

Abstract

Fluorination of the silicon terminated (100) diamond surface under ultra-high vacuum using a molecular fluorine source (C60F48) is investigated with a combination of high resolution photoelectron spectroscopy and low energy electron diffraction. The C60F48 fluorinates the dangling bonds of the silicon-termination on contact, resulting in an inhomogeneous fluorine termination, which remains when the C60F48 is removed by a 550 °C anneal. Despite removing approximately 50% of the surface silicon in the process, the two domain (3 × 1) surface symmetry of the silicon-terminated (100) surface is retained. When exposed to ambient conditions, while some fluorine is displaced by atmosphere exposure, partial fluorination remains. While further optimsation of this process is required for fluorinating diamond in cases where homogeniety and minimised surface damage are desirable, this work demonstrates the potential of the silicon-terminated (100) diamond surface for enabling engineering of the surface properties of diamond.