Pulse Electrodeposition for Improving Electrical Properties of Cu Thin Film

Abstract

Pulse deposition, which has an advantage to apply relatively high current density by supplement of Cu ions during off-time, was applied to deposit 250 nm Cu film. The microstructural change during off-time was to be investigated. The differences between constant potential and pulse deposition were due to the change during off-time. The application of pulse deposition led to the increase in the Cu͑111͒ intensity and the reduction in the film resistivity compared to constant potential deposition. The film characteristics were further improved as the duty cycle decreased. The change during the off-time was verified to be grain growth in contact with the electrolyte. Additionally, it was clarified that the grain growth completed in a second, unlike self-annealing process, which proceeded for tens of hours, and affected within about 2.0 nm of Cu film from the surface. Under optimum conditions, pulse deposition led to 50% enhancement in Cu͑111͒ intensity and 30% reduction in resistivity compared to the constant potential deposition.

Controllable Crystallographic Texture in Copper Foils Exhibiting Enhanced Mechanical and Electrical Properties by Pulse Reverse Electrodeposition

“…An anodic pulse also aids in the formation of twin boundaries because of the strains formed. , In addition to the dissolution of loosely bonded atoms, removal of entrapped hydrogen, impurities, etc., also happens during the anodic pulse. Hence, with the applied cathodic and anodic pulses with optimal on and off times, a number of microstructural changes that could influence the texture take place.…”

“…Anodic pulse also aids in the formation of twin boundaries due to the strains formed 77,79 . In addition to the dissolution of loosely bonded atoms, removal of entrapped hydrogen and impurities, etc.…”

Electrochemical Synthesis and Characterization of p-CuBi2O4 Thin Film Photocathodes

“…Another technique commonly employed to increase nucleation density is pulsed electrodeposition (PED). This technique calls for short deposition periods separated by quiescent periods, which are needed to avoid diffusion limitations that can become significant as the solution near the electrode becomes depleted of metal cations . Various pulse times (with equivalent rest times) ranging from 0.25 to 10 s were investigated with total deposition times of 1 or 2 min, but significant improvements in neither the surface coverage nor photocurrent were observed.…”

“…This technique calls for short deposition periods separated by quiescent periods, which are needed to avoid diffusion limitations that can become significant as the solution near the electrode becomes depleted of metal cations. 29 Various pulse times (with equivalent rest times) ranging from 0.25 to 10 s were investigated with total deposition times of 1 or 2 min, but significant improvements in neither the surface coverage nor photocurrent were observed. It may be reasonable to conclude that the mild potential of −0.5 V vs Ag/AgCl fixed in this work for Cu and Bi codeposition did not generate large enough deposition current densities relative to precursor concentration for PED to have a noticeable effect.…”

A systematic study of pulse and pulse reverse plating on acid copper bath for decorative and functional applications

“…PC mainly used to influence the mechanisms of electrocrystallisation, which in turn control the mechanical and physical properties of the deposited metal 16 , 17 . Since the nucleation rate is proportional to the current density, the use of pulsed single or bipolar currents, which can reach densities significantly higher than their stationary counterparts, can produce deposits with reduced porosity and, a finer grain size 18 , 19 . During t off , when the current is interrupted, the ions of the active metal diffuse towards the electrode, where their concentration has decreased due to the deposition process.…”