Method for thinning ring type ultrathin wafer

The invention relates to a ring-type ultrathin wafer thinning method, and belongs to the technical field of semiconductor processing. The method comprises the following steps: S1, providing a wafer, wherein the wafer comprises a functional surface and a back surface opposite to the functional surface; s2, forming a protective layer on the functional surface of the wafer; covering a protective adhesive tape on the protective layer; s3, placing the wafer in a grinding device, and starting to grind the front surface of the wafer; the grinding device comprises a chuck and a grinding pad arranged opposite to the chuck, and S4, cleaning the wafer. Through the arrangement of the grinding pad, the grinding surface with the high rotating speed can be fixed and stably protected through the grinding surface with the low rotating speed, cracks are prevented from occurring on the grinding surface, and the wafer surface machining quality can be improved. 本发明涉及一种环式晶圆超薄片减薄方法，属于半导体加工技术领域。该方法包括：S1、提供晶圆，所述晶圆包括功能面以及与功能面相对的背面；S2、