Degradation of the Deposition Blocking Layer During Area-Selective Plasma-Enhanced Atomic Layer Deposition of Cobalt

The effects of plasma on the degradation of the deposition blocking layer during area-selective atomic layer deposition were investigated. Co atomic layer deposition (ALD) processes were developed by using Co(iPr-AMD)(2) (bis (N,N'-diisopropylacetamidinato)cobalt(II)) as a precursor, and two different reactants, NH3 gas for thermal ALD (TH-ALD) and NH3 plasma for plasma-enhanced ALD (PE-ALD). TH- and PE-ALD were applied to area selective ALD (AS-ALD) by using an octadecyltrichlorosilane (OTS) self-assembled monolayer (SAM) as a blocking layer. Both ALD processes produced pure Go films with resistivities as low as 50 mu Omega cm. For PE-ALD, however, no selective deposition was achieved due to a degradation of the OTS hydrophobicity caused by the NH3 plasma exposure. The effects of the plasma on the blocking efficiency of SAM were studied.