Additives superconformal electrodeposition

Theories of leveling by additives are based on (1) the correlation between an increase in polarization produced by the leveling agents (29) and (2) preferential adsorption of a leveling agent on high points (peaks or flat surfaces) (30). Theories and modeling of superconformal electrodeposition are discussed in Section 19.4. 

Defect-free deposits in vias and trenches, superconformal electrodeposition, may be achieved in the presence of additives. In superconformal deposition, electrodeposition... 

Mechanism of Superconformal Electrodeposition. Two mechanisms for supercon-formal deposition in the presence of additives were proposed ... 

The inhibition-acceleration mechanism. Moffat et al. (37) proposed the inhibition-acceleration mechanism to explain the experimentally observed comer rounding (inversion of curvature. Fig. 19 in Ref. 37) and general shape evolution in superconformal electrodeposition of copper in vias and trenches of nanometer dimensions (37,38). These authors also smdied a three-additive system composed of two inhibitors and one accelerator. They concluded that superconformal deposition and comer rounding may be attributed to competitive adsorption of inhibitor and accelerator. This model is based on the assumption of curvature (in vias and trenches) -enhanced accelerator coverage. 

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