Adhesive sheet for back surface polishing, method for manufacturing semiconductor wafer, and substrate sheet

The present invention provides an adhesive sheet for polishing a back surface, which can inhibit peeling of an adhesive layer and can easily peel off a wafer from the adhesive sheet. According to the present invention, it is possible to provide: an adhesive sheet for polishing the back surface of a semiconductor wafer having a convex portion; the semiconductor wafer includes a substrate layer and an adhesive layer provided on the substrate layer, and the adhesive layer has an opening portion having a diameter smaller than that of the semiconductor wafer and is attached to an outer peripheral portion of the semiconductor wafer such that a convex portion of the semiconductor wafer is disposed in the opening portion. In a state in which the semiconductor wafer is attached to the adhesive layer, the protruding portion is protected by the base material layer, the base material layer includes a buffer layer and a surface treatment layer provided on the buffer layer, and the adhesive layer is provided on the surface