Research Article

Micro-texturing into DLC/diamond coated molds and dies via high density oxygen plasma etching

¹ Department of Regional Environment, Shibaura Institute of Technology, 3-9-14 Shibaura, Minato-City, Tokyo 108-8548, Japan
² Department of Engineering and Design, Shibaura Institute of Technology, 3-9-14 Shibaura, Minato-City, Tokyo 108-8548, Japan

^* email: taizawa@sic.shibaura-it.ac.jp

Received: 23 January 2015
Accepted: 9 June 2015

Abstract

Diamond-Like Carbon (DLC) and Chemical Vapor Deposition (CVD)-diamond films have been widely utilized not only as a hard protective coating for molds and dies but also as a functional substrate for bio-MEMS/NEMS. Micro-texturing into these hard coated molds and dies provides a productive tool to duplicate the original mother micro-patterns onto various work materials and to construct any tailored micro-textures for sensors and actuators. In the present paper, the high density oxygen plasma etching method is utilized to make micro-line and micro-groove patterns onto the DLC and diamond coatings. Our developing oxygen plasma etching system is introduced together with characterization on the plasma state during etching. In this quantitative plasma diagnosis, both the population of activated species and the electron and ion densities are identified through the emissive light spectroscopy and the Langmuir probe method. In addition, the on-line monitoring of the plasmas helps to describe the etching process. DLC coated WC (Co) specimen is first employed to describe the etching mechanism by the present method. Chemical Vapor Deposition (CVD) diamond coated WC (Co) is also employed to demonstrate the reliable capacity of the present high density oxygen plasma etching. This oxygen plasma etching performance is discussed by comparison of the etching rates.