Dislocation-free Si crystals have been grown successfully from heavily B-doped Si melts by Czochralski (CZ) method without the Dash necking process. No dislocation was introduced in the heavily B-doped Si seed during dipping and no dislocation was generated in the grown crystal due to lattice misfit between the seed and grown crystal when the B concentration is the same in both the Si seed and grown crystal. These results show that the Dash necking process is unnecessary in heavily B-doped Si crystal growth. It is found that the limit of the B concentration in the Si seed for growing dislocation-free CZ-SI crystals without Dash necking is in the order of 10(18) atoms/cm(3), corresponding to a resistivity of several tens of mn cm.