[en] In this study, we analyzed the properties of Cu films electrodeposited with 3-N,N-dimethylaminodithiocarbamoyl-1-propanesulfonate (DPS) as an organic additive in damascene Cu electrodeposition, in comparison with bis(sulfopropyl) disulfide (SPS). It was observed that the resistivity of Cu film electrodeposited with DPS was lower than that with SPS. Spectroscopic analyses showed that the impurity level and crystallinity of Cu films are almost the same, but the difference was found in the film roughness. Low roughness of Cu film electrodeposited with DPS led to the low resistivity, and it was speculated that the low roughness is related to the strong adsorption through the nitrogen atom in the DPS molecule.

[en] Cu growth phenomena during electroless deposition (ELD) on Ru substrate were investigated in this study. Different to the formaldehyde based Cu ELD bath, the use of hydrazine based Cu ELD bath facilitated the observation of Cu growth phenomena during ELD. The whole surface-catalyzed ELD occurred on Ru, and electrochemical quartz crystal microbalance as well as linear sweep voltammetry studies revealed that Cu covered Ru surface within a few seconds of ELD. Measurement of sheet resistance change confirmed that Cu nucleation on Ru was continuous with forming a film. During the period, Cu film growth was monitored by an atomic force microscope imaging, indicating that Cu was deposited on Ru preferentially, rather than on the deposited Cu at the initial stage of the deposition. The whole surface-catalyzed ELD achieved 55 nm gap-filling, and this showed the possibility of the practical adoption of ELD as a method for metallization in ultralarge-scale integration