Atomic layer deposition of stoichiometric Co3O4 films using bis(1,4-di-iso-propyl-1,4-diazabutadiene) cobalt

We report the deposition of cobalt oxide films at 120-300 degrees C using alternating injections of a novel liquid cobalt precursor, bis(1,4-di-iso-propyl-1,4-diazabutadiene)cobalt [C16H32N4Co, Co(dpdab)(2)], and ozone. The saturation doses of Co(dpdab)(2) and O-3/O-2 were 4 x 10(6) and 1 x 10(8) L, respectively. The atomic layer deposition (ALD) temperature window was between 120 degrees C and 250 degrees C with a maximum growth per cycle of 0.12 nm/cycle. The deposited films showed excellent step coverage. Cobalt oxide films deposited at 250 degrees C consisted of stoichiometric and crystalline Co3O4. (C) 2015 Elsevier B.V. All rights reserved.