Physicochemical Characteristics of Copper Microstrip Lines of Microwave ICs Passivated with Accelerated Argon Ions

Abstract

It is found that there are difficulties in restoring the initial chemical activity of copper after passivation by means of ion-beam treatment. The physicochemical and electrical parameters of copper coatings passivated with accelerated medium-energy Ar ions, as well as the microwave characteristics of microstrip lines based on them, are investigated. The modes of ion-beam passivation leading to a significant increase in the chemical resistance of copper are ascertained. It is shown that depassivation of ion-passivated copper layers is possible in an oxygen plasma, in etching solutions with hydrofluoric acid, and by treatment with short ultraviolet radiation. Ion-beam passivation leaves the microwave characteristics of copper microstrip lines almost unchanged with an increase in their resistance to oxidation up to 100 times. The results suggest the possibility of using ion-beam passivation technology for the use of ion-passivated copper as an analog of gold in microwave microelectronic devices.