Wafer processing method and grinding apparatus

A wafer processing method for processing a first wafer of a bonded wafer in which the first wafer and a second wafer are bonded, the wafer processing method comprising:

• forming a ring-shaped modified layer by holding the second wafer of the bonded wafer on a holding table and applying a laser beam with a focal point of the laser beam positioned on an inner side adjacent to a chamfered portion formed at an outer periphery of the first wafer of the bonded wafer;
• loading the bonded wafer onto a grinding apparatus for grinding the first wafer of the bonded wafer;
• and
• grinding the first wafer to thin the first wafer and remove the chamfered portion formed at the outer periphery of the first wafer by a grinding force, wherein
• the loading or the grinding includes supplying a fluid for weakening a bonding force to an interface of the chamfered portion at which the first wafer and the second wafer are bonded.