Silicon wafer, method for determining production conditions of silicon single crystal and method for producing silicon wafer

A silicon wafer, wherein an epitaxial layer is not formed on a surface, and number of LSTDs having a size of 50 nm or more existing in a surface layer portion is 0.23 number/cm2 or less.

A method for determining production conditions of a silicon single crystal, which comprises pulling one or more nitrogen-doped silicon single crystals by the Czochralski method while varying at least one of a ratio V/G of pulling rate V and temperature gradient G at a solid-liquid interface and a passage time PT for a temperature zone where grown-in defects agglomerate, producing silicon wafers from the silicon single crystal or crystals, subjecting the silicon wafers to a heat treatment, measuring a characteristic value of the silicon wafers to determine acceptability of the wafers based on a characteristic value, obtaining correlation between the acceptability and V/G and PT, and determining productions conditions based on the correlation.

A method for producing a silicon wafer comprising producing a silicon wafer from a silicon single crystal pulled by the Czochralski method with nitrogen doping and subjecting the silicon wafer to a heat treatment, wherein the silicon single crystal is pulled so that a ratio V/G of a pulling rate V of the single crystal and a temperature gradient G at solid-liquid interface, and a passage time PT for a temperature zone where grown-in defects agglomerate should be lower than a value of V/G and shorter than a time of PT, respectively, that are uniquely defined by nitrogen concentration and oxygen concentration in the silicon single crystal conditions of heat treatment to which the silicon wafer is subjected, and grown-in defect density of the silicon wafer obtained after the heat treatment.