Optical emission spectra from microwave oxygen plasma produced by surfatron discharge

Abstract

This paper is devoted to a systematic study of the production of molecular and atomic ions and excited atoms in a microwave oxygen plasma generated by surfatron in a quartz tube (i.d. 6 mm). The content of O ⁺₂ , O⁺ and O is measured, using the optical emission spectroscopy, in a wide range of oxygen pressures (from 3.5 Pa to 10² Pa) and microwaves powers (from about 30 W to 300 W) delivered into the plasma. It is shown that the content of individual species O2⁺, O⁺ and O strongly depends on the conditions, particularly operating pressurep and the microwave powerP, under which plasma is created. It means that the chemical reactivity of microwave plasma also strongly depends onp andP. It is of great importance for many practical applications, e.g. for a reproducible production of thin films with prescribed properties.