COMPOSITE SUBSTRATE MANUFACTURING METHOD AND COMPOSITE SUBSTRATE

摘要

PROBLEM TO BE SOLVED: To provide a composite substrate which makes a thickness of a piezoelectric substrate uniform with high accuracy. ! SOLUTION: A manufacturing method of a composite substrate 10 comprises: (a) a process of polishing one surface 14a of a support substrate 14 in a state of applying an offset load on a predetermined outer peripheral part P of the support substrate 14 to make the one surface 14a be an inclined surface 14c which inclines to the other surface 14b; (b) a process of bonding a piezoelectric substrate 12 to the inclined surface 14c of the support substrate 14 to form a bonded substrate 16; (c) a process of processing the piezoelectric substrate 12 so as to make an exposed surface 12b of the piezoelectric substrate 12 of the bonded substrate 16 on the side opposite to the surface which is bonded to the inclined surface 14c of the support substrate 14 be parallel with the other surface 14b of the support substrate 14; and (d) a process of polishing the piezoelectric substrate 12