A Detailed Investigation of Radicals and Ions in ECR Methane/Argon Microwave Discharge

In this work, we focus on study of the formation and behavior of molecules, radicals, and ions in ECR discharge in a mixture of argon and methane. Discharge properties are studied at various conditions; total gas flow (0–50 sccm), absorbed microwave power (0–900 W) and the partial pressure of methane (0–1.2 Pa). Neutral mass spectrometry does not reveal the presence of radical CH5 commonly described in literature. Spectra show the presence of atomic hydrogen H and especially H2 molecules. The number of CH4+ and CH3+ species shows that the amount of CH4+ in areas power up to 350 W is high, but with further increase of the power their amount decreases. With the increasing power the CH3+ ions are more intensively generated. The obtained data helps optimize process conditions for the fabrication of diamond and DLC thin films.