XPS depth analysis of CuO by electrospray droplet impact

The electrospray droplet impact (EDI) is presented as a new etching technique that induces almost no surface damage left after irradiation. We have previously reported that selective etching was not observed after EDI irradiation for organic materials. The present work made a comparative XPS study on the CuO etched by Ar + and EDI. Although marked reduction of CuO was observed with Ar + etching, no chemical modification was occurred by EDI. The etching rate of a few nm/min with EDI was estimated for copper oxide under the present experimental conditions.