Method for manufacturing silicon epitaxial wafers

摘要

A method for manufacturing an epitaxial wafer includes: a step of pulling a single crystal from a boron-doped silicon melt in a chamber based on a Czochralski process; and a step of forming an epitaxial layer on a surface of a silicon wafer sliced from the single crystal. The single crystal is allowed to grow while passed through a temperature region of 800 to 600°C in the chamber in 250 to 180 minutes during the pulling step. The grown single crystal has an oxygen concentration of 10 x 10 17 to 12 x 10 17 atoms/cm 3 and a resistivity of 0.03 to 0.01 ©cm. The silicon wafer is subjected to pre-annealing prior to the step of forming the epitaxial layer on the surface of the silicon wafer, for 10 minutes to 4 hours at a predetermined temperature within a temperature region of 650 to 900°C in an inert gas atmosphere. The method is to fabricate an epitaxial wafer that has a diameter of 300 mm or more, and that attains a high IG effect, and involves few epitaxial defects.