Patent ID: 9074298
Filing Date: 2015-07-07
Classification: C30B

Abstract:
1. A process for manufacturing a silicon ingot, comprising: dipping a seed crystal in a melt in a crucible in a hot zone, wherein: growing the silicon single crystal pulled after the dipping obtain the silicon ingot, wherein the growing comprises using a single crystal puller provided with a thermal shield plate for shielding the silicon ingot against radiant heat from the melt; wherein a distance between the thermal shield plate and a surface of the melt is 20 to 30 mm at the beginning of growing a straight body portion of the silicon ingot, in the growing, a distance between the thermal shield plate and the surface of the melt is 6 to 15 mm in growing the straight body portion from a position of 200 mm away from a boundary between a shoulder portion and the straight body portion in a direction opposite to a pulling direction of the silicon ingot, in the growing, a diameter of the produced silicon ingot is 200 mm; and a length of a region of the produced silicon ingot having resistivity of no greater than 1.6 mΩcm is no less than 200 mm in a longitudinal direction in a case of arsenic; a length of a region of the produced silicon ingot having resistivity of no greater than 0.8 mΩcm is no less than 100 mm in a longitudinal direction in a case of phosphorous; a length of a region of the produced silicon ingot having resistivity of no greater than 0.8 mΩcm is no less than 50 mm in a longitudinal direction in a case of a combination of phosphorous and germanium.