METHODS FOR PRODUCING LOW OXYGEN SILICON INGOTS

摘要

An method for producing a silicon ingot includes melting polycrystalline silicon in a crucible enclosed in a vacuum chamber to form a melt, generating a cusped magnetic field within the vacuum chamber, dipping a seed crystal into the melt, withdrawing the seed crystal from the melt to pull a single crystal that forms the silicon ingot, wherein the silicon ingot has a diameter greater than about 150 millimeters (mm), and simultaneously regulating a plurality of process parameters such that the silicon ingot has an oxygen concentration less than about 5 parts per million atoms (ppma). The plurality of process parameters include a wall temperature of the crucible, a transport of silicon monoxide (SiO) from the crucible to the single crystal, and an evaporation rate of SiO from the melt.

主权项

1. A method for producing a silicon ingot, the method comprising:
melting polycrystalline silicon in a crucible enclosed in a vacuum chamber to form a melt; generating a cusped magnetic field within the vacuum chamber; dipping a seed crystal into the melt; withdrawing the seed crystal from the melt to pull a single crystal that forms the silicon ingot, wherein the silicon ingot has a diameter greater than about 150 millimeters (mm); and simultaneously regulating a plurality of process parameters such that the silicon ingot has an oxygen concentration less than about 5 parts per million atoms (ppma), wherein the plurality of process parameters include a wall temperature of the crucible, a transport of silicon monoxide (SiO) from the crucible to the single crystal, and an evaporation rate of SiO from the melt.