Silicon single crystal wafer and method for producing it

Abstract

There is disclosed a method for producing a silicon single crystal in accordance with the Czochralski method wherein a crystal is pulled with controlling a temperature in a furnace so that ΔG may be 0 or a negative value, where ΔG is a difference between the temperature gradient Gc (° C./mm) at the center of a crystal and the temperature gradient Ge (° C./mm) at the circumferential portion of the crystal, namely ΔG=(Ge−Gc), wherein G is a temperature gradient in the vicinity of a solid-liquid interface of a crystal from the melting point of silicon to 1400° C., and with controlling a pulling rate in a range between a pulling rate corresponding to a minimum value of the inner line of OSF region and a pulling rate corresponding to a minimum value of the outer line, when OSF region is generated in an inverted M belt shape in a defect distribution chart which shows a defect distribution in which the horizontal axis represents a diameter of the crystal and the vertical axis represent a pulling rate. There can be provided a method of producing a silicon single crystal wafer by CZ method wherein OSF in the ring shape distribution generated when being subjected to thermal oxidation or latent nuclei of OSF is present in a low density, and neither FPD, COP, L/D, LSTD nor defect detected by Cu decoration is present under a stable manufacture condition.

Dependencies are inferred from the claim text.