Current-voltage characteristics of a magnetron with a hot titanium target in chemically active environments

Abstract

This work analyzes the results of original experimental studies focused on the discharge current-voltage (I-V) characteristics of a magnetron with a hot titanium target in environments containing reactive gases. Our work presents a fundamental study of a direct current gas discharge with a hot cathode in chemically active environments with a magnetic field applied. The results obtained are useful for practical applications in the development of technologies for the deposition of oxide, nitride and other films. It is found that regardless of the gas environment composition, the I-V characteristics reflect the physical processes in the discharge with a hot target. At low currents, there is a competition of two processes on the target surface, namely, the formation of a titanium compound film and its removal due to sputtering with argon ions and evaporation. A distinctive feature of the hot target discharge is the influence of the thermionic emission of the target, the quenching of metastable argon atoms by atoms and molecules of reactive gases and possibly an additional increase in the rarefaction of the gas near the target due to its heating not only by sputtered atoms but also by evaporated ones on the I-V characteristics. Furthermore, calculations using the Richardson–Dushman equation show that the presence of reactive gases entails a change in the electron work function of titanium.