Patent ID: 8728911

Claim:
An optical device wafer processing method for processing an optical device wafer having an epitaxy substrate and an optical device layer formed on a front side of said epitaxy substrate through a buffer layer, said optical device wafer having an optical device area where a plurality of optical devices are formed and a peripheral marginal area surrounding said optical device area, said buffer layer of said optical device wafer being to be broken in a condition where said optical device layer of said optical device wafer is bonded through a bonding metal layer to a transfer substrate, said optical device wafer processing method comprising: a wafer holding step of holding said transfer substrate bonded to said optical device wafer on a chuck table of a laser processing apparatus; and a buffer layer breaking step of applying a pulsed laser beam having a wavelength having transmissivity to said epitaxy substrate and having absorptivity to said buffer layer from a back side of said epitaxy substrate to said buffer layer, thereby breaking said buffer layer; said buffer layer breaking step including a first laser beam applying step of completely breaking said buffer layer corresponding to said optical device area and a second laser beam applying step of incompletely breaking said buffer layer corresponding to said peripheral marginal area.