US Patent 11107973 Joined body of piezoelectric single-crystal substrate and support substrate

A bonded body includes a supporting substrate; a piezoelectric single crystal substrate composed of a material selected from the group consisting of lithium niobate, lithium tantalate and lithium niobate-lithium tantalate; and an amorphous layer present between the supporting substrate and piezoelectric material substrate, and the amorphous layer contains one or more metal atoms selected from the group consisting of niobium and tantalum, an atom constituting the supporting substrate, and an argon atom. A concentration of the argon atom in a central part of the amorphous layer is higher than a concentration of the argon atom in a peripheral part of the amorphous layer.