Quantifying adhesion strength for Cu/Ta barriers/FTEOS dielectric using modified edge lift off test

Abstract

Quantification of the adhesion strength of backend interconnect diffusion barrier films deposited onto FTEOS dielectric was conducted by a method known as modified edge lift off test (MELT). The objective is to investigate the adhesion strength differences between Ta and TaN single layer as well as Ta/TaN bilayer films. The FTEOS/barrier interface was found to be the weakest among all the different barriers tested. The presence of different films on top of the diffusion barriers (Cu/TaN/FTEOS versus SiN/TaN/FTEOS) was found to affect the adhesion strength to the FTEOS interface. © 2005 Materials Research Society.