Abstract: A manufacturing method for wafers includes: radiating a laser beam to a planned cutoff surface where the ingot is to be cutoff; and forming, with the radiation of the laser beam, a plurality of reformed sections at the planned cutoff surface to extend a crack from the reformed section, thereby slicing wafers, wherein an energy density of the laser beam exceeds a reforming threshold. The energy density satisfies at least one of conditions of a peak value of the energy density is lower than or equal to 44 J/cm2, a rising rate of the energy density at a portion corresponding to the most shallow position where the energy density reaches the reforming threshold Eth is larger than or equal to 1000 J/cm3, and a range of depth where the energy density exceeds the reforming threshold is smaller than or equal to 30 ?m.

Abstract: A manufacturing method of semiconductor wafers includes preparing a ingot having a first major surface and a second major surface in a back side of the first major surface, a peeling layer being formed in the ingot along the first major surface; and applying a load to the ingot from outside thereof with respect to a surface direction along the first major surface such that a moment with a supporting point which is a first end of the ingot in the surface direction acts on the ingot, thereby peeling a wafer precursor from the ingot. Also, a dynamic force may be applied to the ingot such that a tensile stress along an ingot thickness direction acts on an entire area of the ingot in the surface direction, thereby peeling the wafer precursor from the ingot.