Super secondary grain growth in the barrier/seedlayer system

Abstract

A new grain growth mode is observed in thick copper seed layers deposited on alpha-Ta barriers. It leads to highly concentric growth and grains of many tens of microns. Initiation and growth of the grains is shown to be dependent on both the barrier properties and the copper layer thickness. A clear rivalry between this growth mode and normal secondary grain growth is observed, where the latter dominates at elevated temperatures. Also the final grain orientations are very different as no (111) growth is observed for the new mechanism.