US 7,582,357 B2 · Silicon semiconductor substrate

Abstract

The present invention can provide a silicon semiconductor substrate used for and epitaxial wafer, in which uniform and high-level gettering ability is obtained irrespective of slicing positions from a silicon single crystal while generation of epitaxial defects can be suppressed, by doping carbon or carbon along with nitrogen during a pulling process of a CZ method or by performing appropriate heat treatment prior to the epitaxial process. Therefore, a crystal production yield can remarkably be improved because a permissible upper limit (concentration margin) of an oxygen concentration which is restricted by formation of a ring-shaped OSF region can be higher and also an excellent gettering ability is exhibited, while allowing an epitaxial wafer to be produced wherein epitaxial defects attributable to substrate crystal defects are not formed.

Claims4

Dependent claims

An epitaxial wafer which includes an epitaxial layer on a surface of a silicon semiconductor substrate,

wherein
the silicon semiconductor substrate is grown by the Czochralski method on a condition that a ring-shaped region of oxygen induced stacking fault emerges in a crystal surface over a whole length of a straight body portion of a pulled silicon single crystal, and wherein
the silicon semiconductor substrate is sliced from the silicon single crystal, which has dopants consisting of carbon and boron, with boron ranging from 1×1017 to 1×1019 atoms/cm3 and carbon ranging from 1×1015 to 2×1016 atoms/cm3 (ASTM F123-1981), and wherein the number of defect to be observed on the surface of the epitaxial wafer is not more than 10 count/wf.

Dependencies are inferred from the claim text.

Silicon semiconductor substrate

Life of this patent

Silicon semiconductor substrate

Life of this patent

Abstract

Claims4