Filling of nanoscale holes with high aspect ratio by Cu electroplating using suspension of supercritical carbon dioxide in electrolyte with Cu particles

We reported filling of nanoscale holes with high aspect ratio by Cu electroplating with a supercritical carbon dioxide suspension (EP-SCS). The Cu film electrodeposited by the EP-SCS was smooth. The nanoscale holes with 70 nm in diameter and aspect ratio of 2 and 5 can be filled by electrodeposited Cu with no voids and pinholes by the EP-SCS. Gap-filling capability of the EP-SCS is high for the nanoscale holes with high aspect ratio even when using Cu electrolyte originally designed to fill holes with 70 nm diameter and aspect ratio 1 by conventional method.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► We propose Cu electroplating in supercritical CO2 suspension (EP-SCS) with Cu particles. ► Nanoscale holes with 70 nm in diameter is filled by Cu using this method. ► Filling of holes with aspect ratio of 2 and 5 is completed with no void and pinhole. ► Gap-filling capability of EP-SCS is high for nanoscale holes with high aspect ratio.