Patent ID: 9530929
Filing Date: 2016-12-27
CPC Classification: G01N,H01L,H01S

Claim Text:
1. A lift-off method for transferring an optical device layer in an optical device wafer to a transfer substrate, said optical device layer being formed on a front side of an epitaxy substrate through a buffer layer, said lift-off method comprising: a composite substrate forming step of bonding said transfer substrate through a bonding agent to the front side of said optical device layer of said optical device wafer, thereby forming a composite substrate; a buffer layer breaking step of applying a laser beam having a wavelength transmissive to said epitaxy substrate and absorptive to said buffer layer from a back side of said epitaxy substrate to said buffer layer after performing said composite substrate forming step, thereby breaking said buffer layer; and an optical device layer transferring step of peeling off said epitaxy substrate from said optical device layer after performing said buffer layer breaking step, thereby transferring said optical device layer to said transfer substrate; said buffer layer breaking step including a composite substrate heating step of heating said composite substrate to thereby relieve spring back produced in said epitaxy substrate and said transfer substrate prior to applying said laser beam to said buffer layer.