Cylindrical silicon ingot manufacturing method

A cylindrical ingot manufacturing method comprising:

• a melting operation in which a silicon raw material is supplied to an inside of a crucible, and the crucible is heated to melt the silicon raw material;
• a supplying operation in which one end of a seed crystal having a ring-shaped cross-section is fastened to a seed shaft, and the seed crystal is supplied to the inside of the crucible;
• and
• a growing operation in which the seed crystal is moved from a lower portion of the crucible to an upper portion thereof by the crucible rotating in one direction relative to the seed shaft and the seed shaft rotating in an other direction and moving upward,
• wherein the growing operation includes:
• a first speed adjusting operation in which a speed at which the seed shaft rotates in the other direction is adjusted so that the seed crystal forms an ingot in a predetermined shape;
• and
• a second speed adjusting operation in which a speed at which the seed shaft moves from the lower portion of the crucible to the upper portion thereof is adjusted.