Cobalt oxide has been deposited with remote plasma ALD over a wide temperature window (100 - 400 °C), using CoCp2 as cobalt precursor and with a remote O2 plasma as oxidant source. This novel combination resulted in the deposition of high density (6.2 g/cm3), stoichiometric Co3O4 with an electrical resistivity between 0.5 and 5.3 O cm. Several merits have been identified for this process. Compared to the literature, the temperature window was widened to 100 - 400 °C and the growth per cycle was higher at 0.05 nm/cycle, almost independent of the substrate temperature.
Investigation of the material properties revealed cubic Co3O4 films with a preferential (111) direction for all temperatures with an increasing crystallinity with temperature. Furthermore, the plasma assisted process resulted in smooth Co3O4 films with a roughness of = 1 nm for all substrate temperatures and film thicknesses (5 -65 nm) investigated. Mass spectrometry measurements reveal a combustion-like reaction process.
|Title of host publication||Atomic layer deposition applications 5 : Proceedings of the 216th ECS meeting, 4 - 9 October 2009, Vienna, Austria|
|Editors||S. Bent, S. Gendt, De|
|Place of Publication||Pennington, NJ|
|Publisher||Electrochemical Society, Inc.|
|Publication status||Published - 2009|