Manganese Precursor Selection and the Thermal Atomic Layer Deposition of Copper/Manganese Alloy Films

This paper describes the thermal ALD growth of Cu/Mn alloy films using the precursors Cu(OCHMeCH2NMe2)2, Mn2(tBuNCHC(tBu)(Me)O)4, and BH3(NHMe2) at 160 °C. Deposition rates of about 0.09 Å/cycle were observed on a variety of substrates. Cu:Mn ratios of about 70:30 were obtained by controlling the number of Cu and Mn cycles. X-ray photoelectron spectroscopy supports the presence of metallic Cu and Mn within the Cu/Mn alloys. Similar precursors and chemistry were used to deposit 35-50 nm thick Cu/Mn/Cu film stacks on Ru, Pd, and Pt substrates. Depth profiling of stacks that were overcoated with an SiO2 layer showed that the Mn atoms diffuse to the SiO2/Cu interface in samples grown on Pd and Pt, both in as-deposited films and those that were annealed at 350 °C. With Ru substrates, the Mn atoms collected slightly at the SiO2/Cu interface, but primarily remained distributed throughout the film in as-deposited and annealed samples.