Processes for production of silicon ingot, silicon wafer and epitaxial wafer, and silicon ingot

Abstract

A process for production of a silicon ingot, by which a silicon ingot exhibiting a low resistivity even in the top portion can be produced. The process for the production of a silicon ingot includes withdrawing a silicon seed crystal from a silicon melt to grow a silicon single crystal, with the silicon seed crystal and the silicon melt containing dopants of the same kind. The process includes the dipping step of dipping a silicon seed crystal containing a dopant in a specific concentration in a silicon melt in such a manner that the temperature difference between both falls within the range of 50 to 97K, and the growing step of growing a silicon single crystal withdrawn after the dipping to form a silicon ingot, the growing step being conducted by using a single crystal puller provided with a thermal shield plate for shielding against radiant heat emitted from the silicon melt and controlling the distance between the thermal shield plate and the silicon melt within a specific range.