With the miniaturization of various electronic devices, there is a huge demand to develop high-density packaging technology based on flip chips. However, the oxidation of the metal electrode surface poses a serious challenge for metal interconnections. Cleaning the metal electrodes with hydrogen radicals generated by the hot-wire (HW) method removes the metal oxide and controls the effects of formation of native oxide. This technique has attracted much attention as a surface treatment strategy for microconnections. In the present work, metal oxide removal using hydrogen radicals generated by the plasma-enhanced methods and by the HW method has been investigated and compared. (C) 2014 Elsevier B.V. All rights reserved.