Die having through-substrate vias with deformation protected tips

A method of fabricating through-substrate via (TSV) die, comprising:

• thinning from an initial bottom side of a substrate having a TSV die including a top side semiconductor surface including active circuitry therein comprising a plurality of transistors functionally connected attached to a carrier to reach a bottom side surface to expose a plurality of embedded filled vias to form a plurality of TSVs which extend from said top side semiconductor surface to TSV tips having exposed distal tip ends that protrude from said bottom side surface and comprise an inner metal core comprising an electrically conductive filler material surrounded by a dielectric liner that forms an outer edge for said plurality of TSVs;
• depositing a tip deformation protecting layer comprising an inorganic dielectric material on said bottom side surface, wherein an elastic modulus of said inorganic dielectric material is greater than (>) an elastic modulus of said electrically conductive filler material;
• forming a second dielectric layer comprising a polymer on said tip deformation protecting layer before chemical mechanical polishing (CMP), and
• said CMP to reveal said distal tip ends of said TSV tips.