Silicon crystals containing different levels of arsenic concentration and oxygen content were grown, and samples were taken at various positions along the crystal, to study the influence of three main factors, i.e. the initial oxygen content, the dopant concentration and the thermal history, on the nucleation of oxygen precipitates during crystal growth and cooling in the puller. The crystal thermal history was reconstructed by means of computer modeling, simulating the temperature distribution in the crystal at several growth stages. The oxygen precipitation was characterized after a thermal cycle of 4 h at 800 degrees C for nuclei stabilization +16 h at 1000 degrees C for nuclei growth. Oxygen precipitates were counted under microscope on the cleaved sample surface after preferential etching. Lightly doped silicon samples were also included, as reference. Our results show that even in heavily arsenic doped silicon the oxygen precipitation is a strong function of the initial oxygen concentration, similar to what has been observed for lightly doped silicon. In addition, a precipitation retardation effect is observed in the arsenic doped samples when the dopant concentration is higher than 1.7 x 10(19) cm(-3) compared to lightly doped samples with the same initial oxygen content and crystal thermal history. Finally, a long permanence time of the crystal in the temperature range between 450 degrees C and 750 degrees C enhances the oxygen precipitation, showing that this is an effective temperature range for oxygen precipitation nucleation in heavily arsenic doped silicon. (C) 2016 Elsevier B.V. All rights reserved.