Electrochemical dissolution of both Ta and TaN into 2.5 M HF is demonstrated by cyclic voltammetry. For Ta dissolution, current maxima typical of passive film formation are seen, and the peak current occurs at about - 420 mV vs a saturated calomel electrode (SCE), while that for TaN dissolution occurs at about + 50 mV SCE. This report of electrochemical Ta and TaN dissolution demonstrates the possibility of all-electrochemical, noncontact methods for removal of Cu diffusion barrier materials. Four-point probe measurements demonstrate that the removal rates of Ta and TaN can be varied within the range of 0 to 15 nm/min through the appropriate choice of potential. (c) 2005 The Electrochemical Society.