METHOD FOR PRODUCING HIGH-QUALITY SILICON SINGLE CRYSTAL

摘要

PURPOSE: To provide a method for growing a high-quality single crystal having a large diameter and long length, capable of collecting a wafer having grown-in defects such as metastasis dislocation cluster and infrared scatter reduced as much as possible by a CZ method. CONSTITUTION: This method for producing a silicon single crystal comprises pulling the single crystal by making the shape of a solid-liquid interface during pulling into an upper projected state having height of central part >= 6 cm higher than the circumferential part and applying a magnetic field to a melt or pulling the single crystal by making a temperature gradient in the direction of pulling axis between a melting point to 1,200deg.C to lessen the temperature gradient more at the circumferential part than at the central part besides the above-mentioned conditions. In this case, a part at least 60 mm above the melt level of the surface of the single crystal is screened from direct radiant heat of a heater or the wall face of a crucible or a magnetic field having 0.08-0.3T in the horizontal direction in parallel with the melt surface is applied to the melt or a cusp magnetic field having 0.02-0.07T is applied to the melt at the position of the wall face of the crucible of the surface of the melt and the rotative speed of the crucible is made > 5 min-1 and that of the single crystal is made > 13 min-1.