Metal whisker growth induced by localized, high-intensity DC electric fields

In this work, a very high, locally applied electric field was used to induce whisker nucleation on an Sn film. The field was generated by using a conductive AFM tip and applying a voltage bias between the sample and the conductive cantilever. The tip-sample separation distance was thus controllable, and any dielectric breakdown could be avoided. At locations where the AFM tip was positioned for an extended period, minuscule whiskers were observed, whose growth direction matched vertical orientation of the field.