Method for evaluating metal contamination of silicon single crystal

Abstract

A method for evaluating metal contamination of a silicon single crystal grown by the Czochralski method using a pulling apparatus in which a voltage can be applied between a crystal suspending member and a crucible comprises the steps of: setting the crystal suspending member as a negative electrode while setting the crucible as a positive electrode in a process for growing a non-convertible portion of the silicon single crystal; applying the voltage; collecting a sample from the non-convertible portion grown in association with the voltage application; and evaluating the metal contamination of the sample by an analysis in which Surface Photo Voltage method is adopted. In a process for growing an end-product convertible portion of the silicon single crystal, the voltage is applied such that the crystal suspending member is set as the positive electrode while the crucible is set as the negative electrode, or the voltage is not applied.

Dependencies are inferred from the claim text.