A method (10) of forming a MIM (metal insulator metal) capacitor is disclosed whereby adverse affects associated with copper diffusion are mitigated even as the capacitor is scaled down. A layer of bottom electrode/copper diffusion barrier material (136) is formed (16) within an aperture (128) wherein the capacitor (100) is to be defined. The bottom electrode layer (136) is formed via a directional process so that a horizontal aspect (138) of the layer (136) is formed over a metal (110) at a bottom of the aperture (128) to a thickness (142) that is greater than a thickness (144) of a sidewall aspect (148) of the layer (136) formed upon sidewalls (132) of the aperture (128). Accordingly, the thinner sidewall aspects (148) are removed during an etching act (18) while some of the thicker horizontal aspect (138) remains. A layer of capacitor dielectric material (150) is then conformally formed (20) into the aperture 128 and over the horizontal aspect (138). A layer of top electrode material (152) is then conformally formed (22) over the layer of capacitor dielectric material (150) to complete the capacitor stack (154).