Characterization of an ultrahigh vacuum (UHV) sputtering system.

摘要

Contamination from the gas source, target, or system can cause impurities to become incorporated in a sputtered film. These impurities can harm the sputtered film e.g., in terms of electromigration and microstructure properties.;A custom-designed ultra-high vacuum sputtering system was constructed to study trace levels of background contaminants allowed by different pump combinations. Turbomolecular and cryogenic pumps each selectively aided by a LN2 trap and a titanium sublimation pump were used. Contamination was measured with RGAs at base pressures and at 1 mT. The main contaminants for the cryo-based system were air and hydrogen at ppb levels and for the turbo-based system were air and water at ppm levels. This was true at both high and low pressures. Also shown was the need for both open and closed ion source RGAs and the superior trace detection capability of the open source.