US 12,288,720 B2
Semiconductor chip, processed wafer, and method for manufacturing semiconductor chip
Masatake Nagaya, Nisshin (JP); and Daisuke Kawaguchi, Hamamatsu (JP)
Assigned to DENSO CORPORATION, Kariya (JP); TOYOTA JIDOSHA KABUSHIKI KAISHA, Toyota (JP); MIRISE Technologies Corporation, Nisshin (JP); and HAMAMATSU PHOTONICS K.K, Hamamatsu (JP)
Filed by DENSO CORPORATION, Kariya (JP); TOYOTA JIDOSHA KABUSHIKI KAISHA, Toyota (JP); MIRISE Technologies Corporation, Nisshin (JP); and HAMAMATSU PHOTONICS K.K., Hamamatsu (JP)
Filed on Feb. 25, 2022, as Appl. No. 17/680,464.
Claims priority of application No. 2021-035558 (JP), filed on Mar. 5, 2021.
Prior Publication US 2022/0285219 A1, Sep. 8, 2022
Int. Cl. H01L 21/78 (2006.01); H01L 21/26 (2006.01); H01L 21/784 (2006.01); H01L 23/544 (2006.01); H01L 29/66 (2006.01); H01L 33/00 (2010.01); H10D 30/01 (2025.01); H10D 89/00 (2025.01); H10H 20/01 (2025.01)
CPC H01L 21/7813 (2013.01) [H01L 21/26 (2013.01); H01L 23/544 (2013.01); H10D 89/013 (2025.01); H01L 2223/54433 (2013.01); H10D 30/015 (2025.01); H10H 20/01 (2025.01); H10H 20/0137 (2025.01); H10H 20/018 (2025.01)] 13 Claims
OG exemplary drawing
 
1. A method for manufacturing a semiconductor chip formed with a semiconductor element, the method comprising:
preparing a gallium nitride wafer made of gallium nitride;
producing a processed wafer by forming an epitaxial film on a surface of the gallium nitride wafer, the processed wafer having a first surface on a side of the epitaxial film and a second surface on a side of the gallium nitride wafer, the processed wafer including a plurality of chip formation regions adjacent to the first surface of the processed wafer;
forming a first surface-side element component of the semiconductor element in each of the plurality of chip formation regions;
forming a wafer transformation layer, in which nitride is separated from gallium, along a horizontal direction of the processed wafer by irradiating an inside of the processed wafer with a laser beam from the second surface side of the processed wafer;
dividing the processed wafer at the wafer transformation layer as a boundary into a chip formation wafer including the first surface of the processed wafer and a recycle wafer including the second surface of the processed wafer;
extracting the semiconductor chip from the chip formation wafer; and
after the preparing of the gallium nitride wafer and before the dividing of the processed wafer, forming a mark inside of one of the gallium nitride wafer and the processed wafer by irradiating an inside of the one with a laser beam, the mark being formed by a decomposition of the gallium nitride,
wherein
the forming the mark includes forming a wafer mark as the mark, after the preparing of the gallium nitride wafer and before the forming of the first surface-side element component.