Separation method of wafer
AssigneeDisco Corporation
InventorsAsahi Nomoto, Kazuya Hirata
Life of this patent
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Abstract
A wafer having a first surface, an opposite second surface, and an outer circumferential surface that includes a curved part curved outward in a protruding manner is separated into two wafers. Part of the wafer is removed along the curved part, and a separation origin is formed inside the wafer by positioning the focal point of a laser beam with a wavelength having transmissibility with respect to the wafer inside the wafer and executing irradiation with the laser beam while the focal point and the wafer are relatively moved in such a manner that the focal point is kept inside the wafer. The wafer is separated into two wafers by an external force.
Claims18
A separation method of a wafer by which the wafer having a first surface, a second surface on a side opposite to the first surface, and an outer circumferential surface that is located between the first surface and the second surface and that includes a curved part curved outward in a protruding manner is separated into two wafers, the separation method comprising:
- a processing step of processing the wafer to remove part of the wafer along the curved part, wherein the entire outer circumferential surface is at least partially planarized between the first surface and the second surface in the processing step;
- a separation origin forming step of, after the processing step, forming the separation origin inside the wafer by positioning a focal point of a laser beam with a wavelength having transmissibility with respect to the wafer inside the wafer and executing irradiation with the laser beam while the focal point and the wafer are relatively moved in such a manner that the focal point is kept inside the wafer;
- and
- a separation step of separating the wafer into a first wafer having the first surface and a second wafer having the second surface from the separation origin by giving an external force after the separation origin forming step.
A separation method of a wafer by which the wafer having a first surface, a second surface on a side opposite to the first surface, and an outer circumferential surface that is located between the first surface and the second surface and that includes a curved part curved outward in a protruding manner is separated into two wafers, the separation method comprising:
- a processing step of processing the wafer to remove part of the wafer along the curved part to form a groove that extends in a straight line manner along a portion of the curved part which extends in a straight line manner;
- a separation origin forming step of, after the processing step, forming the separation origin inside the wafer by positioning a focal point of a laser beam with a wavelength having transmissibility with respect to the wafer inside the wafer and executing irradiation with the laser beam while the focal point and the wafer are relatively moved in such a manner that the focal point is kept inside the wafer;
- and
- a separation step of separating the wafer into a first wafer having the first surface and a second wafer having the second surface from the separation origin by giving an external force after the separation origin forming step.
A separation method of a wafer by which the wafer having a first surface, a second surface on a side opposite to the first surface, and an outer circumferential surface that is located between the first surface and the second surface and that includes a curved part curved outward in a protruding manner is separated into two wafers, the separation method comprising:
- a processing step of processing the wafer to remove part of the wafer along the curved part to form a groove in the first surface;
- a separation origin forming step of, after the groove has been formed in the processing step, forming the separation origin inside the wafer by positioning a focal point of a laser beam with a wavelength having transmissibility with respect to the wafer inside the wafer and executing irradiation with the laser beam while the focal point and the wafer are relatively moved in such a manner that the focal point is kept inside the wafer, wherein the focal point is positioned to a depth between the first surface of the wafer and a bottom surface of the groove, and a region surrounded by the groove of the wafer is irradiated with the laser beam;
- and
- a separation step of separating the wafer into a first wafer having the first surface and a second wafer having the second surface from the separation origin by giving an external force after the separation origin forming step.
Dependencies are inferred from the claim text.