Epitaxial wafer and a method for producing it

Abstract

The present invention provides an epitaxial wafer wherein a silicon epitaxial layer is formed on a surface of a silicon single crystal wafer in which nitrogen is doped, and a density of oxide precipitates having such a size that a gettering capability can be achieved in a bulk is 108 numbers/cm3 or more. And the present invention also provides a method for producing an epitaxial wafer wherein a silicon single crystal in which nitrogen is doped is pulled by Czochralski method, the silicon single crystal is processed into a wafer to produce a silicon single crystal wafer, and the silicon single crystal wafer is subjected to heat treatment so that a density of oxide precipitates having such a size that a gettering capability can be achieved in a bulk of the wafer may be 108 numbers/cm3 or more, and then the silicon single crystal wafer is subjected to epitaxial growth. A silicon single crystal wafer which surely has a high gettering capability irrespective of a device process can be obtained herewith.

Dependencies are inferred from the claim text.