Lift off method

Abstract

The present invention provides a lift-off method capable of reliably peeling off an epitaxial substrate. Provided is a lift-off method for transferring an optical device layer of an optical device wafer to a transfer substrate, which includes a transfer substrate bonding process, bonding the transfer substrate to the surface of the optical device layer of the optical device wafer; a gas layer forming process, The buffer layer is irradiated with pulsed laser light from the back side of the epitaxial substrate of the optical device wafer to form a gas layer at the interface between the epitaxial substrate and the buffer layer; the gas layer detection process detects the outermost gas in the formed gas layer the area of ​​the layer; the epitaxial substrate adsorption process, positioning the suction pad to the area where the outermost gas layer detected by the gas layer detection process in the epitaxial substrate is located, to adsorb the epitaxial substrate; and the optical device layer transfer process, The suction pad holding the epitaxial substrate is moved in a direction away from the epitaxial substrate to peel off the epitaxial substrate, and transfer the optical device layer to the transfer substrate.

Description

technical field [0001] The present invention relates to a lift-off method for transferring an optical device layer of an optical device wafer in which an optical device layer is stacked on a surface of an epitaxy substrate such as a sapphire substrate or silicon carbide via a buffer layer to a transfer substrate. Background technique [0002] In the optical device manufacturing process, an optical device layer composed of an n-type semiconductor layer and a p-type semiconductor layer is laminated on the surface of a substantially disk-shaped sapphire substrate or an epitaxial substrate such as silicon carbide through a buffer layer, and is formed in a lattice Optical devices such as light-emitting diodes and laser diodes are formed in multiple regions divided by multiple intervals in the shape of a light-emitting diode to form an optical device wafer. The n-type semiconductor layer and the p-type semiconductor layer are made of GaN (gallium nitride) or INGaP ( gallium indium...

AI Technical Summary

Problems solved by technology

[0007] However, when the laser light is irradiated from the back side of the epitaxial substrate by positioning the focus point on the buffer layer, there is a problem that since GaN or INGaP or ALGaN constituting the buffer layer are decomposed into Ga and N 2 and other gases, the buffer layer is destroyed, but there is GaN or INGaP or ALGaN decomposed into Ga and N 2 In the region where the gas is equal to the gas and in the region where there is no decomposition, the destruction of the buffer layer is uneven, so the epitaxial substrate cannot be properly peeled off

Images