Crystal layer separation method, laser irradiation method and method of fabricating devices using the same

Abstract

Disclosed are a crystal layer separation method capable of separating a crystal layer formed on a substrate therefrom without occurrence of any crack, and a laser irradiation method used therefor, and a method of fabricating devices using the same. The crystal layer separation method includes the step of separating a crystal layer made from a GaN based compound formed on a sapphire substrate therefrom by irradiating the crystal layer with a laser beam from the back surface of the substrate, wherein the crystal layer is irradiated with the laser beam in a line-shape. In this method, an irradiation width of the laser beam is preferably equal to or less than a thickness of the crystal layer, and the laser beam preferably has a light intensity distribution smoothened in the width direction.

Dependencies are inferred from the claim text.