ALEXANDRIA, Va., Dec. 9 -- United States Patent no. 12,491,581, issued on Dec. 9, was assigned to DISCO Corp. (Tokyo).
"Wafer producing method" was invented by Kazuya Hirata (Tokyo) and Ryohei Yamamoto (Tokyo).
According to the abstract* released by the U.S. Patent & Trademark Office: "A wafer producing method includes a peel-off layer forming step of forming a peel-off layer by positioning a focused spot of a laser beam having a wavelength transmittable through an ingot to a depth corresponding to a thickness of the wafer to be produced from the ingot from a first end surface of the ingot and applying the laser beam to the ingot, a first chamfered portion forming step of forming a first chamfered portion by applying, from the first end s...