Electrochemical and Solid-State Letters vol:12 issue:5 pages:D39-D41
Blind holes 5 mu m diam and 25 mu m in depth were filled with electrodeposited copper. Before electrodeposition, the blind holes were fully metallized with a copper seed layer or with a thin sputtered Ta layer deposited on top of the copper seed layer. Filling of partially Ta-capped features was three times faster than filling fully metallized features. For fully metallized features, the growth mode for copper electrodeposition is dominated by diffusion adsorption of a leveling agent. For partially Ta-capped surfaces, the growth mode was modified to differential acceleration through accumulation of an accelerating species at the bottom of features.