INFRARED STUDY OF THE EFFECT OF RAPID THERMAL ANNEALING, THERMAL DONOR FORMATION, AND HYDROGEN ON THE PRECIPITATION OF OXYGEN

The influence of rapid thermal annealing thermal donor formation, and hydrogen on the precipitation of oxygen was studied by infrared analys es. We concluded that the oxygen loss during the subsequent precipitat ion Steps is not directly correlated with the quantity of thermal dono rs formed. Our study supports rather that thermal donors are made of s elf-interstitial agglomerates. However, a 450 degrees C treatment and a prior rapid thermal annealing enhances the precipitation of oxygen, through a path which does not lead,to platelets. Indeed spherical prec ipitates evidenced by infrared analyses are formed early at low temper ature, during the thermal treatment at 750 degrees C. They may grow fr om aggregates, formed at 450 degrees C, and we think that they are mad e of oxygen atoms and vacancies. The growth of these aggregates occurs as the temperature of the thermal treatments increases and is enhance d by a prior rapid thermal anneal. Finally, a retardation of the preci pitation due to hydrogen introduced during a pretreatment was observed in specific conditions.