Effects of amino-terminated self-assembled monolayers on nucleation and growth of chemical vapor-deposited copper films

Abstract

Copper films were grown on clean Si, SiO 2 and 3-amino-propyl-trimethoxy-silane (APTMS) self-assembled monolayers (SAMs)-modified SiO 2 substrates via chemical vapor deposition (CVD) and were examined using scanning electron microscopy, atomic force microscopy, and X-ray diffraction (XRD). Ordered APTMS-SAMs obtained from a 3 mM concentration solution were found to enhance adhesion of the films on the SiO 2 substrate surface. However, in 60 mM solution, APTMS layers tended to be multilayered and formed islands via self-polymerization. Copper nucleation on APTMS-SAMs modified substrate surfaces occurs more easily than on the clean Si and SiO 2 substrate surfaces. Enhanced copper CVD was ascribed to the interaction of Cu atoms with the N-containing terminal groups of APTMS-SAMs. The XRD analysis showed that the copper thin films deposited on the APTMS-modified SiO 2 substrates have a structure with (111) preferred orientation, which is known to have a good electromigration resistance.