Atomic Layer Deposited Coatings on Nanowires for High Temperature Water Corrosion Protection.

Two-phase liquid-cooling technologies incorporating micro/nanostructured copper or silicon surfaces have been established as a promising thermal management solution to keep up with the increasing power demands of high power electronics. However, the reliability of nanometer-scale features of copper and silicon in these devices has not been well investigated. In this work, accelerated corrosion testing reveals that copper nanowires are not immune to corrosion in deaerated pure hot water. To solve this problem, we investigate atomic layer deposition (ALD) TiO2 coatings grown at 150 and 175 °C. We measured no difference in coating thickness for a duration of 12 days. Using a core/shell approach, we grow ALD TiO2 /Al2 O3 protective coatings on copper nanowires and demonstrate a preservation of nanoengineered copper features. These studies have identified a critical reliability problem of nanoscale copper and silicon surfaces in deaerated, pure, hot water and have successfully demonstrated a reliable solution using ALD TiO2 /Al2 O3 protective coatings.