XPS studies on damage evaluation of single-crystal diamond chips processed with ion beam etching and reactive ion beam assisted chemical etching

Abstract

A number of ion beam techniques were examined for their ability to etch single-crystal diamond. Both etching ability and the amount of resulting surface damage were examined. The techniques evaluated included ion beam etching (IBE), reactive ion beam etching (RIBE), ion beam assisted chemical etching (IBAE) and reactive ion beam assisted chemical etching (RIBAE). Etching rate of RIBAE processing of diamond is higher than other processing methods and it is 1.98 μm/h. When using the oxygen ion beam methods (RIBE and RIBAE processing), adsorption of oxygen occurs on the sample surface, and subsequent annealing treatment desorbs the oxygen that was previously adsorbed on surface of the diamond. Moreover, when the annealing treatment was carried out on the diamond with RIBE processing, damage of the diamond surface was observed using X-ray photoelectron spectroscopy (XPS). As a result, with all of the ion beam processes studied, the diamond crystal structure is changed into graphite or amorphous structures. Among the four processing methods, the RIBAE processing method exhibits the least amount of damage on the diamond crystal structure. Previously in this type of research, ion beam damage was seldom investigated. We also show that XPS measurement is an effective means for the evaluation of ion beam damage.