Process for filling etched holes using photoimageable thermoplastic polymer

Abstract

A process for filling one or more etched holes defined in a frontside surface of a wafer substrate. The process includes the steps of: (i) depositing a layer of a photoimageable thermoplastic polymer onto the frontside surface and into each hole; (ii) reflowing the polymer; (iii) selectively removing the polymer from regions outside a periphery of each hole, the selective removing comprising exposure and development of the polymer; (iv) optionally repeating steps (i) to (iii) until each hole is overfilled with the polymer; and (v) planarizing the frontside surface to provide one or more holes filled with a plug of the polymer. Each plug has a respective upper surface coplanar with the frontside surface.

Dependencies are inferred from the claim text.