Stripping of carbon coatings in radio-frequency inductively coupled plasma of H2/Ar

Abstract

This article describes the stripping of amorphous carbon (a-C) coatings in an H 2 /Ar atmosphere using a radio-frequency inductively coupled plasma (RF-ICP) source. The power of the RF-ICP source, atmosphere composition (H 2 /Ar) and bias potential strongly affect the stripping rate (0.7–9.3 μm/h), while the operating pressure has less influence (2.7–3.2 μm/h). The selectivity of stripping of a-C and titanium coatings can be varied from 1 up to ~90 by changing the atmosphere composition. Chemical sputtering plays a key role in the productivity and selectivity of carbon stripping, it should have a higher rate compared to physical sputtering to enable high selectivity of coating stripping. Raman spectroscopy reveals the increase in graphitization degree and decreasing less ordered carbon of a-C coatings under stripping in H 2 /Ar plasma. Phase transformations of sublayer or substrate materials could occur under coating stripping in a reactive atmosphere in the example of hydride formation (TiH 2-x ) in a Ti sublayer. • Stripping of carbon coatings in RF-ICP plasma of H 2 /Ar. • Stripping selectivity of carbon coatings is regulated by H 2 /Ar flow rates. • Graphitization of a-C coatings under stripping in H 2 /Ar plasma.