Bonded substrate and method for manufacturing bonded substrate

Abstract

A bonded substrate having a high bonding strength in which the formation of voids is suppressed is provided. A bonded substrate according to an aspect of the present disclosure is a bonded substrate in which a first substrate and a second substrate are bonded to each other through their bonding surfaces. The first substrate includes a first modified layer on the side thereof on which its bonding surface is located, and the second substrate includes a second modified layer on the side thereof on which its bonding surface is located. A method for manufacturing a bonded substrate according to an aspect of the present disclosure is a method for manufacturing a bonded substrate in which a first substrate and a second substrate are bonded to each other, the method including: a step of plasma-treating a surface of the first substrate and thereby forming a first modified layer over the surface of the first substrate; a step of plasma-treating a surface of the second substrate and thereby forming a second modified layer over the surface of the second substrate; a step of temporarily bonding the first and second substrates to each other in a state where the first and second modified layers face each other; and a step of annealing the temporarily-bonded substrates and thereby bonding the first and second substrates to each other.

Dependencies are inferred from the claim text.