Ar ion induced copper germanide phase formation at room temperature

Abstract

The copper germanide phase Cu3Ge which is emerging as an alternative material for making contacts and interconnects for semiconductor industry has been produced across the interface of Cu/Ge bilayers by ion beam mixing at room temperature using 1 Me V Ar ions. The dose dependence of the thickness of the mixed region shows a diffusion controlled mixing process. The experimental mixing rate and efficiency for this phase are 5.35 nm4 and 10.85 nm5keV respectively. At doses above 8 × 1015 Ar/cm2 the formation and growth of another copper rich phase Cu5Ge has been observed. The present theoretical models are inadequate to explain the observed experimental mixing rate.