Semiconductor wafer manufacturing method, method of manufacturing semiconductor energy beam detecting element, and semiconductor wafer

A semiconductor wafer manufacturing method, comprising:

• preparing a semiconductor wafer having a first semiconductor region of a first conductivity type, the first semiconductor region including a first main surface and a second main surface facing each other;
• providing a second semiconductor region of a second conductivity type on the first main surface side of the first semiconductor region, the second semiconductor region forming an energy ray sensitive region together with the first semiconductor region;
• providing a third semiconductor region of the first conductivity type on the second main surface side of the first semiconductor region, the third semiconductor region having a higher impurity concentration than the first semiconductor region;
• forming a side surface in a chip portion by providing a through-slit penetrating entirely through the semiconductor wafer such that the through-slit does not have a bottom in a thickness direction along a second virtual cutting line of a first virtual cutting line and the second virtual cutting line, the side surface to which the first semiconductor region is exposed, the chip portion including the energy ray sensitive region, the first virtual cutting line and the second virtual cutting line defining the chip portion as viewed from a direction perpendicular to the first main surface, a shortest distance from the second virtual cutting line to an edge of the second semiconductor region being smaller than a shortest distance from the first virtual cutting line to the edge of the second semiconductor region;
• and
• providing a fourth semiconductor region of the first conductivity type on the side surface side by adding impurities to the side surface,
• wherein the through-slit, which penetrates entirely through the semiconductor wafer, is formed before the step of providing the fourth semiconductor region.