US Patent 7459720 Single crystal wafer and solar battery cell

The present invention provides a single crystal wafer, wherein the main surface has a plane or a plane equivalent to a plane tilting with respect to a [100] axis of single crystal by angles of α (0°<α<90°) for the [011] direction, β (0°<β<90°) for the [01-1] direction and γ (0°≦γ<45°) for the [10-1] or [101] direction. Thus, a single crystal wafer that can sufficiently bear device production processes even with a small wafer thickness is provided and thereby loss of single crystal raw material is reduced. Further, by using such a wafer, MIS type semiconductor devices and solar cells are provided at a low cost.