Lift-off method

A lift-off method of transferring an optical device layer of an optical device wafer, which has the optical device layer formed on a front face of an epitaxy substrate with a buffer layer provided therebetween, onto a transfer substrate, the lift-off method comprising:

• a complex substrate formation step of forming a complex substrate by joining the transfer substrate to a front face of the optical device layer of the optical device wafer with an adhesive;
• a buffer layer destruction step of irradiating a laser beam having a wavelength that penetrates the epitaxy substrate and is absorbed by the buffer layer from a rear side of the epitaxy substrate of the complex substrate so as to destroy the buffer layer;
• and
• an optical device layer transfer step of peeling off the epitaxy substrate of the complex substrate that has been subjected to the buffer layer destruction step and transferring the optical device layer onto the transfer substrate,
• wherein the optical device layer transfer step heats and cools the complex substrate to produce thermal distortion between the epitaxy substrate and the transfer substrate to which the optical device layer has been joined so as to destroy the buffer layer and peel off the epitaxy substrate,
• wherein the complex substrate is heated to 100° C or more and cooled to 20° C. or less in the optical device layer transfer step, and
• wherein the heating and cooling of the complex substrate is performed by:
• injecting heated air upon the complex substrate via a fluid nozzle located in a holder member, and
• injecting cooled air upon the complex substrate via the fluid nozzle located in the holder member.