Abstract: An annealed wafer having enhanced gettering effects for Cu is produced by heating a silicon substrate containing a nitrogen concentration of 5×1014 to 1×1016/cm3, a carbon concentration of 1×1015 to 5×1016/cm3, and an oxygen concentration of 6×1017 to 11×1017/cm3 at a temperature of 650 to 800° C. for a time ?4 hours, and subjecting the heated substrate to argon annealing at a temperature of 1100 to 1250° C., wherein internal stacking fault density after annealing is ?5×108/cm3.

Abstract: A semiconductor substrate after heat-treatment in a non-oxidising atmosphere has the characteristics that the depth of the denuded zone may be greater than 12 &mgr;m or the defect-free depth of the void type defect is greater than 12 &mgr;m and the substrate has a locally densified portion produced by nitrogen segregation and exhibiting a signal strength two or more times the average signal strength at the depth of 12 &mgr;m or more below the surface thereof when measuring the concentration of nitrogen by using secondary ion mass-spectroscopy, and the density of the crystal defect of oxygen precipitates is 5×108/cm3 or more, and the said substrate is produced by heat-treating for at least one hour at the temperature of 1200° C. or more in a non-oxidising atmosphere.

Abstract: A silicon semiconductor substrate which realizes a defect-free region of void type crystals to a greater depth and allows the duration of production to be decreased and a method for the production thereof are provided. A silicon semiconductor substrate derived from a silicon single crystal grown by the Czochralski method or the magnetic field-applied Czochralski method, which is obtainable by using a silicon semiconductor substrate satisfying the relational expression, 0.2≧V/S/R, providing V denotes the volume of void type defects, S denotes the surface area thereof, and R denotes the radius of spherical defects presumed to have the same volume as the void defects having the volume of V, and heat treating this substrate at a temperature exceeding 1150° C.

Abstract: A silicon semiconductor substrate which realises a defect-free region of void type crystals to a greater depth and allows the duration of production to be decreased and a method for the production thereof are provided.

Abstract: A semiconductor substrate after heat-treatment in a non-oxidising atmosphere has the characteristics that the depth of the denuded zone may be greater than 12 &mgr;m or the defect-free depth of the void type defect is greater than 12 &mgr;m and the substrate has a locally densified portion produced by nitrogen segregation and exhibiting a signal strength two or more times the average signal strength at the depth of 12 &mgr;m or more below the surface thereof when measuring the concentration of nitrogen by using secondary ion mass-spectroscopy, and the density of the crystal defect of oxygen precipitates is 5×108/cm3 or more, and the said substrate is produced by heat-treating for at least one hour at the temperature of 1200° C. or more in a non-oxidising atmosphere.