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 degrees 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 SiO2, resulting in self-formed MnOx and MnSixOy, respectively. The adhesion between Cu and SiO2 was enhanced by the formation of MnSixOy. Continuous and conductive Cu-Mn seed layers were deposited with PEALD into 24 nm SiO2 trench, enabling a low temperature process, and the trench was perfectly filled using electrochemical plating under conventional conditions. (C) 2012 Elsevier B.V. All rights reserved.