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

Abstract

According to the present invention, there are provided a silicon wafer, wherein an epi-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 0.24 number/cm or less; a method for determining production conditions of a silicon single crystal, which comprises pulling nitrogen-doped silicon single crystals by the CZ method while varying V/G and/or PT, producing silicon wafers from the silicon single crystals, subjecting the silicon wafers to a heat treatment, determining acceptability of the wafers based on a predetermined characteristic value, obtaining correlation between the acceptability and V/G and PT, and determining production conditions based on the correlation; and a method for producing a silicon wafer comprising pulling a silicon single crystal so that V/G and PT should be lower than V/G and shorter than PT that are uniquely defined by predetermined 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. According to the present invention, a nitrogen-doped annealed wafer showing a low defect density even under severe examination conditions and little fluctuation thereof depending on the production condition is produced.