Connected body made of a piezoelectric material substrate and carrier substrate

摘要

(Object) It is an object, in bonding a piezoelectric material substrate 1 (1A) to a support substrate 3 through a bonding layer 2, to prevent the piezoelectric material substrate 1 (1A) from being separated when the bonded body thus obtained is subjected to a heat treatment ) A bonded body contains a carrier substrate 3; a piezoelectric material substrate 1 (1A) comprising a material selected from the group consisting of lithium niobate, lithium tantalate, and lithium niobate-lithium tantalate; and a bonding layer 2 that connects the support substrate 3 and the piezoelectric material substrate 1 (1A) and contacts a main surface 1a of the piezoelectric material substrate. The bonding layer 2 contains a cavity which extends from the piezoelectric material substrate to the carrier substrate.