Heavily arsenic (As) doped Si crystals were grown by the Czochralski (CZ) method, and constitutional supercooling in As-doped CZ-Si crystal growth was investigated. When the As concentration in the crystal was high, cellular growth was induced and SiAs precipitates were then observed following the cellular structure. The As concentration increases in the cellular structure along the growth direction and around the precipitates it reaches approximately 4 at%, which corresponds to the maximum solid solubility of As in Si. According to the estimation of critical growth conditions for constitutional supercooling, it qualitatively obeys the theoretical equation of constitutional supercooling. (C) 2013 Elsevier By. All rights reserved.