  This work reports on the fabrication of microbump structures on Ni films by
single-pulse, localized laser irradiation. Conditions for the reproducible
formation of such microstructures have been identified in terms of
laser-irradiation and film parameters after systematic studies involving a
relevant parameter space. The cracks and voids morphology of the sputtered
films was rendered undesirable and hence, smoother Ni thin film of same
thickness (200nm) were deposited by vacuum evaporation. The continuous nature
of the film resulted in radially symmetric thermal expansion and deformation,
thus achieving a high yield of microstructures. An improvement in the
inductance and the quality factor of on-chip spiral inductors incorporating
such laser-microstructured ferromagnetic nickel thin films was observed, which
demonstrates the potential of such a laser-based method for fabrication or fine
tuning of various micro-/nanoelectric/electronic sensor and other components
and systems.
