Patent ID: 8883610

Claim:
A method, comprising: performing a first selective deposition process to form a conductive cap layer selectively on each of a plurality of metal lines formed in a first dielectric material of a metallization layer of a microstructure device; performing a second selective deposition process so as to form a first etch protection material in a spatially selective manner on each conductive cap layer so as to cover an entirety of each conductive cap layer and protect the conductive cap layer in a subsequent recess etching process, said first etch protection material exposing at least a portion of said first dielectric material between two neighboring ones of said metal lines; performing a third selective deposition process so as to form a second etch protection material in a spatially selective manner on each of said first etch protection materials; with the first and second etch protection materials covering the conductive cap layers, performing the recess etching process to form a recess in said at least a portion of said first dielectric material; and depositing a second dielectric material so as to close said recess and form an air gap on the basis of said recess.