Alternative patterning techniques enabling fine pitch interconnection on topography surfaces

We report on the fabrication of small pitch (20 μm) interconnection structures based on Cu pillars embedded in polymer. Such structures are useful in different applications such as integrated passives and die embedding technologies. To allow the fabrication of such structures, we made use of the diamond bit cutting and dry etching techniques as alternatives to the currently used lithographic process. This latter did not allow targeting such aggressive pitches and structures dimensions.