Apparatus and method for manufacturing semiconductor single crystals

摘要

This invention provides an apparatus and a method for manufacturing semiconductor single crystals, which enable a steady process of pulling up high-quality single silicon crystals to be easily performed during the growing of silicon single crystals by the CZ method aided by applying a Cusp magnetic field. Three facing homopolar magnets (hereinafter referred to as magnet) 1, 2, and 3 arc disposed outside the single-crystal pulling up chamber. The magnet 3 is located at the same height as the free surface of the melt 6 stored in a quartz crucible as the free surface of the melt 6 stored in a quartz crucible 5. Furthermore, the strength of the magnets 3 is set to be weaker than that of the magnets 1 and 2. The flux lines of the magnets 3 substantially pass through the quartz crucible 5 in the horizontal direction. However, the flux lines of the magnet 3 do not reach the silicon single crystal 7 being pulled up. The flux lines perpendicular to the free surface of the melt 6 and the strength of the magnetic field near the growth boundary of the crystal are reduces. Thus, the amount of oxygen coming from the quartz crucible 5 and convection near the free surface of the melt 6, starting from the quartz crucible 5 toward the silicon single crystal, can be minimized.