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

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 mu m/h), while the operating pressure has less influence (2.7-3.2 mu m/h). The selectivity of stripping of a-C and titanium coatings can be varied from 1 up to similar 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 (TiH2-x) in a Ti sublayer.