Additive-free Superfilling in Damascene Cu Electrodeposition using Microcontact Printing

Abstract

To avoid complications brought about by employing organic additives, microcontact printing using a flat stamp was used in forming trench-selective Cu superfilling on damascene structure. Self-assembled monolayers of 1-decanethiol transferred on top surface of the trench could withstand the H2SO4 electrolyte and were used as a barrier for current transfer below a certain potential that was not yet dominated by the tunneling current. Subsequent electrodeposition on the printing area was successfully inhibited. The resulting filling profile was a defect-free superfilling with bumps on top. This is comparable to the three-additive system consisting of accelerator and two-component suppressor.