Enhancements of photoluminescence intensity in high-quality floating-zone Si by thermal annealing in vacuum

Inactivation of non-radiative defects by hydrogen and their thermal stabilities in a high-quality floating-zone Si wafer depending on annealing conditions have been studied using in-situ photoluminescence (PL) and thermal desorption under an ultra-high vacuum. The PL intensity increased to similar to 400% of its initial value after annealing at 450 degrees C and decreased to similar to 6% of its initial value after annealing at 600 degrees C due to inactivation and activation of non-radiative defects, respectively. Based on the annealing temperature-and duration-dependence of the PL intensity, we propose two types of hydrogenated defects with different thermal stabilities. (C) 2016 The Japan Society of Applied Physics