Patent ID: 8877609

Claim:
A method for manufacturing a bonded substrate that is formed by bonding a base substrate to a bond substrate and has an insulator layer in part of the bonded substrate, the method comprising at least: a porous layer forming step of partially forming a porous layer or forming a porous layer whose thickness partially varies on a bonding surface of the base substrate; an insulator layer forming step of performing a heat treatment to the base substrate having the porous layer formed thereon to change the porous layer into the insulator layer, and thereby forming the insulator layer whose thickness partially varies on the bonding surface of the base substrate; an insulator layer removing step of removing the insulator layer whose thickness varies by an amount corresponding to a thickness of a small-thickness portion by etching, and thereby exposing the unetched remaining insulator layer on part of the bonding surface of the base substrate; a bonding step of bonding the bonding surface of the base substrate on which the unetched remaining insulator layer is exposed to the bond substrate; and a thin film forming step of reducing a thickness of the bonded bond substrate and thereby forming a thin film layer.