In-situ ellipsometric characterization of the electrodeposition of metal films

The long-term objective of this work is to develop novel material structures and low-cost methods to prepare magneto-optic thin film materials. Ellipsometry offers diagnostics of the nucleation and growth processes on a nanometer-thickness scale. Magnetic Ni metal films were electrodeposited from sulfamate-based solutions using a galvanostatic technique. The deposition process was monitored in-situ using a spectroscopic ellipsometer measuring at 44 wavelengths simultaneously from 410 to 750 nm in real time. The spectral range for good data was limited by the transparency of the solution. Ellipsometric measurements were used to find the optical constants and growth rates for a series of depositions. Measurements of the charge passing through the sample during the growth were also used to monitor growth rates. These results were compared with the growth rates found from ellipsometric measurements. The comparison shows the two techniques to be in reasonable agreement and the advantages of each technique is discussed.