Abstract: A method for forming an isolating layer of a crucible includes placing a round crucible sideways with a bottom surface of an inside thereof perpendicular to a horizontal plane, and then performing a plurality of spraying processes to form the isolating layer on the bottom surface and a wall surface of the round crucible. Each spraying process includes spraying a slurry on the bottom surface; using an optical positioner to set a spraying range the same as one of a plurality of partial areas divided from the wall surface; aligning one of the plurality of partial areas with the spraying range; fixing the round crucible and spraying the slurry in the spraying range; stopping the spraying; and rotating the round crucible to move another partial area to the spraying range. Then, the steps are repeated until the spraying of all the partial areas is completed.

Abstract: A method for forming an isolating layer of a crucible includes placing a round crucible sideways with a bottom surface of an inside thereof perpendicular to a horizontal plane, and then performing a plurality of spraying processes to form the isolating layer on the bottom surface and a wall surface of the round crucible. Each spraying process includes spraying a slurry on the bottom surface; using an optical positioner to set a spraying range the same as one of a plurality of partial areas divided from the wall surface; aligning one of the plurality of partial areas with the spraying range; fixing the round crucible and spraying the slurry in the spraying range; stopping the spraying; and rotating the round crucible to move another partial area to the spraying range. Then, the steps are repeated until the spraying of all the partial areas is completed.

Abstract: A polycrystalline silicon wafer is provided. The polycrystalline silicon wafer, includes a plurality of silicon grains, wherein the carbon content of the polycrystalline silicon wafer is greater than 4 ppma, and the resistivity of the polycrystalline silicon wafer is greater than or equal to 1.55 ?-cm.

Abstract: A polycrystalline silicon column is provided. The polycrystalline silicon column includes a plurality of silicon grains grown along a crystal-growing direction. In the crystal-growing direction, the average grain size of the silicon grains and the resistivity of the polycrystalline silicon column have opposite variation in their trends, the average grain size of the silicon grains and the oxygen content of the polycrystalline silicon column have opposite variation in their trends, and the average grain size of the silicon grains and the defect area ratio of the polycrystalline silicon column have the same variation in their trends. The overall average defect area ratio of the polycrystalline silicon column is less than or equal to 2.5%.

Abstract: A polycrystalline silicon column is provided. The polycrystalline silicon column includes a plurality of silicon grains grown along a crystal-growing direction. In the crystal-growing direction, the average grain size of the silicon grains and the resistivity of the polycrystalline silicon column have opposite variation in their trends, the average grain size of the silicon grains and the oxygen content of the polycrystalline silicon column have opposite variation in their trends, and the average grain size of the silicon grains and the defect area ratio of the polycrystalline silicon column have the same variation in their trends. The overall average defect area ratio of the polycrystalline silicon column is less than or equal to 2.5%.

Abstract: A polycrystalline silicon wafer is provided. The polycrystalline silicon wafer, includes a plurality of silicon grains, wherein the carbon content of the polycrystalline silicon wafer is greater than 4 ppma, and the resistivity of the polycrystalline silicon wafer is greater than or equal to 1.55 ?-cm.