Cu crystallographic texture control in Cu/refractory-metal layered structure as interconnects

Abstract

The effect of underlayer texture on Cu film orientation has been studied. The crystallographic orientation of sputter-deposited Cu film depends strongly on the underlayer refractory-materials. Cu (111) orientation can be controlled by changing the preferred orientation of the TiN underlayer that has the same cubic structure as Cu. TEM observation of the Cu/RTN–TiN interface has revealed that the Cu (111) plane grows epitaxially on the TiN (111) plane. It has been also clarified that the atomic arrangement between the Cu (111) and TiN (111) planes has a rotational angle within ±10° around the 〈111〉 axis.