Plasma-enhanced atomic layer deposition of Cu–Mn films with formation of a MnSixOy barrier layer

Abstract Conformal Cu–Mn seed layers were deposited by plasma enhanced atomic layer deposition (PEALD) at low temperature (120 °C), and the Mn content in the Cu–Mn alloys were controlled form 0 to approximately 10 atomic percent with various Mn precursor feeding times. Resistivity of the Cu–Mn alloy films decreased by annealing due to out-diffusion of Mn atoms. Out-diffused Mn atoms were segregated to the surface of the film and interface between a Cu–Mn alloy and SiO 2 , resulting in self-formed MnO x and MnSi x O y , respectively. The adhesion between Cu and SiO 2 was enhanced by the formation of MnSi x O y . Continuous and conductive Cu–Mn seed layers were deposited with PEALD into 24 nm SiO 2 trench, enabling a low temperature process, and the trench was perfectly filled using electrochemical plating under conventional conditions.