Abstract: In a splitting method for an optical device wafer, the wafer having optical devices formed individually in regions partitioned by a plurality of crossing scheduled splitting lines provided on a front surface and having a reflective film formed on a reverse surface, a focal point of a laser beam is positioned to the inside of the optical device wafer and the laser beam is irradiated along the scheduled splitting lines from the reverse surface side of the wafer to form modification layers in the inside of the wafer. An external force is applied to the wafer to split the wafer along the scheduled splitting lines and form a plurality of optical device chips. The laser beam has a wavelength that produces transmittance through the reflective film equal to or higher than 80%.

Abstract: A sapphire wafer dividing method including a cut groove forming step of forming a plurality of cut grooves on the back side of a sapphire wafer along a plurality of crossing division lines formed on the front side where a light emitting layer is formed, a modified layer forming step of forming a plurality of modified layers inside the sapphire wafer along the division lines, and a dividing step of dividing the sapphire wafer into individual light emitting devices along the modified layers as a division start point, thereby chamfering the corners of the back side of each light emitting device owing to the formation of the cut grooves in the cut groove forming step.

Abstract: In a splitting method for an optical device wafer, the wafer having optical devices formed individually in regions partitioned by a plurality of crossing scheduled splitting lines provided on a front surface and having a reflective film formed on a reverse surface, a focal point of a laser beam is positioned to the inside of the optical device wafer and the laser beam is irradiated along the scheduled splitting lines from the reverse surface side of the wafer to form modification layers in the inside of the wafer. An external force is applied to the wafer to split the wafer along the scheduled splitting lines and form a plurality of optical device chips. The laser beam has a wavelength that produces transmittance through the reflective film equal to or higher than 80%.

Abstract: A sapphire wafer dividing method including a cut groove forming step of forming a plurality of cut grooves on the back side of a sapphire wafer along a plurality of crossing division lines formed on the front side where a light emitting layer is formed, a modified layer forming step of forming a plurality of modified layers inside the sapphire wafer along the division lines, and a dividing step of dividing the sapphire wafer into individual light emitting devices along the modified layers as a division start point, thereby chamfering the corners of the back side of each light emitting device owing to the formation of the cut grooves in the cut groove forming step.