Activation of amino-based monolayers for electroless metallization of high-aspect-ratio through-silicon vias by using a simple ultrasonic-assisted plating solution

•Seed-trapping APTMS-SAM was used for electroless metallization of TSV in an all-wet manner.•Co(W,P) is non-uniformly coated on TSV using a mechanically agitated solution.•Co(W,P) is evenly and conformably coated on TSV with sonication of the same solution.•Void-free Cu is successively filled into TSV using a simple sonication method.•Alternation of surface structures for the enhancement of seeding is clarified.