Masato Sone
Tokyo Institute of Technology, Japan
Title: Nanoscale wiring by Cu electrodeposition in supercritical CO 2 emulsified electrolyte with continuous-flow reaction system
Biography
Biography: Masato Sone
Abstract
Copper wiring into nanoscale holes with high aspect ratio by electrodeposition is an important problem for 3-D integration in integrated circuit technology toward miniaturization of electronic devices. However, void and pinhole found in Cu wiring for the integration can cause trouble for miniature device. Cu electroplating method without void and pinhole is needed. We have proposed novel electroplating methods with supercritical carbon dioxide (sc-CO2) emulsion (EP-SCE). The electrochemical reaction is carried out in an emulsion of sc-CO2 in electrolyte with surfactants. Sc-CO2 has low viscosity and compatibility of hydrogen. Thus, this method is applicable in fine Cu wiring. The aim of this report is to examine Cu electrodeposition by using sc-CO2 emulsified electrolyte into nano-scale Cu wiring on the viewpoints of dissolution of Cu seed layer, gap-filling capability into nano-scale holes and contamination in the plated Cu. Moreover a continuous-flow reaction system is proposed and examined for filling of Cu into holes with 60 nm in diameter and aspect ratio of 2 and 5 by EP-SCE on a round-type large-area hole test element group with diameter of 300 mm, which has an integrated structure of Cu seed layer on TiN barrier layer sputtered on Si substrates.