Dislocation behavior at the interface between a heavily B-doped or B and Ge codoped Si seed and the grown crystal using Czochralski Si crystal growth under various seeding temperatures was investigated. When the diameter of the grown crystal just below the interface was larger than that of the seed, dislocation were generated in the grown crystal from the edge of the interface due to incomplete seeding. It was found that no dislocations were generated near the interface when the diameter was smaller than that of the seed, and the smaller diameter was simply realized by seeding at a higher temperature before pulling up the crystal. A practical industrial-scale dislocation-free Si crystal 8 in in diameter was successfully grown without a thin neck by suppressing dislocations not only due to thermal shock and lattice misfit but also due to incomplete seeding. (C) 2003 Elsevier B.V. All rights reserved.