Patent ID: 7285841

Claim:
A method of manufacturing signal processing apparatus, including; etching a surface of a substrate to a predetermined depth, forming a recessed portion in the surface of said substrate; forming one of a first interconnecting conductor and a second interconnecting conductor on said substrate including at least the recessed portion of said substrate; filling the recessed portion of said substrate with a sacrificial layer material, and removing the sacrificial layer material on said substrate, excluding at least the recessed portion of said substrate and an area proximate the recessed portion of said substrate; planarizing said a sacrificial layer material so that said sacrificial layer material and one of (i) the surface of said substrate and (ii) said first interconnecting conductor become substantially co-planar with each other as a planarized surface; forming a dielectric support film on at least said planarized surface of said sacrificial layer and said substrate; forming said second interconnecting conductor on said dielectric support film; forming at least one opening opposite said sacrificial layer and passing through said dielectric support film; and removing said sacrificial layer via said opening.