Development and application of a multipurpose electrodeposition cell configuration for studying plating processes on wafer specimen and for characterizing surface films by scanning electrochemical microscopy

In this report, a versatile experimental concept for electrochemical deposition and subsequent surface characterization studies is presented. This concept can be utilized to perform semiconductor plating processes at laboratory scale followed by scanning electrochemical microscopy (SECM). The same sample holder used for electroplating experiments could be integrated into the SECM instrument. Conductive thin-film barrier materials were deposited on planar silicon wafers. The substrate samples were fixed in the multipurpose sample holder ensuring a large electrical contact area to minimize ohmic drop across the sample surface with a small circular area of the substrate material of 16 mm(2) exposed to electrolyte solution. In order to investigate the capabilities of the electrochemical cell configuration, a potentiostatic copper deposition on ruthenium was carried out. Thus, information on film coalescences, grain size, and growth mode could be derived. SECM was used to study the effect of biasing during probe approach curves on a titanium surface. Furthermore, microstructured copper layers were imaged using ferrocenemethanol (FcMeOH) as mediator. The results show that biasing the substrate is essential for non-destructive and interaction-free measurements of semiprecious thin-film materials and copper structures, if FcMeOH is used as electrochemical mediator