The phenomenon of target heating in magnetron sputtering systems: An experimental and theoretical study

Abstract

The aim of this work is to experimentally measure and theoretically estimate the fraction of total discharge power spent on target heating in a DC magnetron sputtering system. To this end, the calorimetric method for in situ measurements of the temperature of Cu, Ti, and Cr targets in Ar and N2 gases and at different discharge powers was used. Using theoretical calculations, the fractions of the total discharge power spent on target heating and on secondary effects observed in the discharge and on the target surface were analyzed and theoretically calculated using computer program trim for each “target–gas” combination. The results of this work are as follows. The temperature of the cooled target turned high, which indicates that the target surface acquires unusual properties during ion bombardment. The temperature of Cu and Ti targets sputtered in N2 at different discharge powers is higher than that when sputtered in Ar, which is presumably a result of chemical reactions on the target surface during sputtering. Experimentally and theoretically, it has been shown that the values of fractions of power spent on heating the target are close, do not depend on the total discharge power, and vary in the range of ∼0.7–0.8.