Abstract: An electrochemical deposition system includes: an electrochemical deposition chamber including an electrolyte for electrochemical deposition; a substrate holder configured to hold a substrate and including a first cathode that is electrically connected to the substrate; a first actuator configured to adjust a vertical position of the substrate holder within the electrochemical deposition chamber; an anode submerged in the electrolyte; a second cathode arranged between the first cathode and the anode; a first optical probe configured to measure a first reflectivity of the substrate at a first distance from a center of the substrate while the substrate is submerged within the electrolyte during the electrochemical deposition; and a controller configured to, based on the first reflectivity, selectively adjust at least one of power applied to the first cathode, power applied to the second cathode, power applied to the anode, and the vertical position of the substrate holder.