Nongrowth regime in microwave chemical vapor deposition reactor due to formation of plasma nonhomogeneity

Abstract

A new form of microwave discharge with a filament inside plasma volume was investigated in a microwave plasma‐assisted chemical vapor deposition (CVD) reactor. The threshold values of methane content in a hydrogen–methane gas mixture, gas pressure, and microwave power for discharge transition to the new form were found. The parameters' range of existence of the new form of discharge was investigated in three types of CVD reactors. Measurements of the electron density, gas temperature, and spatial distributions of the plasma optical emission lines intensity were carried out for both forms of the discharge. The reasons for the transition of the discharge to a new form and the possibility of using the new discharge form in the microwave plasma‐assisted (MPA) CVD reactor are discussed.