Composite semiconductor device

Abstract

Disclosed is a composite semiconductor device, comprising a composite substrate consisting of first and second semiconductor substrates, one surface of each of which is mirror-polished, so that the mirror-polished surfaces are bonded together. The first semiconductor substrate has a space adjacent to the bonding interface, and an annular groove which communicates with the space from a surface of the first semiconductor substrate opposite the bonding interface, the annular groove being formed in a portion of the first semiconductor substrate corresponding to a peripheral edge portion of the space thereof, at least one pillar projecting through the space to the bonding interface from a surface, which is exposed to the space, of a first portion of the first semiconductor substrate which is defined by the space and the annular groove, a first insulating layer, formed in the annular groove, for electrically isolating the first portion from a second portion of the first semiconductor substrate adjacent thereto, a second insulating layer, formed on the pillar or a bonding interface between the pillar and the second semiconductor substrate, for electrically isolating the first portion from the second semiconductor substrate, a first functional element formed in the first portion, and a second functional element formed in the second portion.

Dependencies are inferred from the claim text.