Analyzing Copper Etching Dynamics by Hybridizing AFM Controlled SECM with Raman MicroSpectroscopy

Local etching of a thin copper film evaporated on silicon was investigated by developing Atomic force microscopy (AFM) regulated scanning electrochemical microscopy (SECM). For this investigation such an AFM controlled SECM was hybridized with in-Situ Raman spectroscopy. This allowed for an understanding of the nanometric controlled etching of the copper coating on the silicon. The design of the instrument and the probe has allowed for spectrochemical analysis in real time. The etching produced a micrometer aperture in the copper film which was characterized, in terms of morphology, by the AFM capabilities of the probe. It was discovered that a time gap occurred between the measured SECM current and the exposure of the Si beneath. This was demonstrated by the in-situ Raman spectrometer. An AFM scan of the etched area using the same SECM probe was demonstrated too. Such an integration has allowed for obtaining the type of real time information of the etching processes for understanding in depth the parameters that control etching. As a result, deeper, well quantified insights have been obtained of diffusion mechanisms in redox reactions. The data also leads to new horizons and insights into etching processes in general.