Process for the heat treatment of a silicon wafer, and silicon wafer produced

Abstract

A process for the heat treatment of a silicon wafer, during which the silicon wafer is at least temporarily exposed to an oxygen-containing atmosphere, the heat treatment taking place at a temperature which is selected in such a way that the inequality 1 [ Oi ] < [ Oi ] eq ⁢ ( T ) ⁢ exp ⁢ ( 2 ⁢ σ SiO 2 ⁢ Ω rkT ) is satisfied, where [Oi] is the oxygen concentration in the silicon wafer [Oi]eq(T) is the limit solubility of oxygen in silicon at a temperature T, σSiO2 is the surface energy of silicon dioxide Ω is the volume of a precipitated oxygen atom, r is the mean COP radius and k is the Boltzmann constant. A silicon wafer which in its bulk has a density of nucleation centers for the oxygen precipitation of at least 107 cm−3 and on the wafer front surface has a zone which is free of nucleation centers and is at least 1 μm thick, and has a COP density of less than 10 000 cm−3 down to a depth which corresponds to at least 50% of the wafer thickness.

Dependencies are inferred from the claim text.