Formation of a buried oxide film at the damage peak induced by oxygen implantation into a Si substrate

The formation of a buried oxide layer in a Si substrate by oxygen implantation and subsequent high-temperature annealing is examined. The oxide precipitation, growth, and coalescence processes are enhanced by increasing the oxygen concentration in the annealing atmosphere. These processes are enhanced more effectively at the damage peak, where the implantation damage is at a maximum, than at the concentration peak. Therefore, the buried oxide layer can be formed at the damage peak instead of at the concentration peak by choosing an appropriate ramping rate for the annealing and Ar/O2 ratio in the annealing atmosphere. Double buried oxide layers, with a layer at both the damage peak and the concentration peak, can also be fabricated by using a single sequence of oxygen implantation and high-temperature annealing. In both cases, oxygen atoms introduced from the atmosphere through the surface, as well as the implanted oxygen, contribute to the formation of the buried oxide layers.