Thin Solid Films, Vol.591, 13-17, 2015
Fabrication of a Cu/Ni stack in supercritical carbon dioxide at low-temperature
We report the low-temperature deposition of Cu on a Ni-lined substrate in supercritical carbon dioxide. A novel Cu(I) amidinate precursor was used to reduce the deposition temperature. From the temperature dependence of the growth rate, the activation energy for Cu growth on the Ni film was determined to be 0.19 eV. The films and interfaces were characterized by Auger electron spectroscopy. At low temperature (140 degrees C), we successfully deposited a Cu/Ni stack with a sharp Cu/Ni interface. The stack had a high adhesion strength (>1000 mN) according to microscratch testing. The high adhesion strength originated from strong interfacial bonding between the Cu and the Ni. However, at a higher temperature (240 degrees C), significant interdiffusion was observed and the adhesion became weak. (C) 2015 Elsevier B.V. All rights reserved.
Keywords:Supercritical carbon dioxide;Cu(I) amidinate;Low-temperature;Cu/Ni stack;Thin films;Adhesion strength