Annealing dynamics of irradiation-induced defects in high-purity silicon in the presence of hydrogen

作者：Bleka J H^*; Malmbekk H; Monakhov E V; Svensson B G; Avset B S

来源：Physical Review B, 2012, 85(8): 085210.

DOI：10.1103/PhysRevB.85.085210

A reaction model explaining (i) the hydrogen-mediated transformation of the vacancy-oxygen (VO) center into a vacancy-oxygen-hydrogen center (VOH*), with an energy level at 0.37 eV below the conduction-band edge (E-c), and (ii) the passivation of the divacancy center is presented. VOH* dissociates with a rate of 2 x 10(-5) s(-1) at 195 degrees C, causing VO to recover after long duration (> 10(4) min), while a similar evolution occurs at 300 degrees C on a time scale of the order of 10 min. The diffusivity of the monatomic hydrogen used in the model agrees closely with the established values for the diffusivity of protons. After the recovery of VO, further annealing at higher temperatures and/or longer durations transforms VO into the "ordinary" vacancy-oxygen-hydrogen center with an energy level at E-c -0.32 eV (V OH). VOH is subsequently transformed into VOH2. For temperatures above 250 degrees C, two additional hydrogen-related levels occur (similar to 0.17 and similar to 0.58 eV below E-c) with a one-to-one ratio and a possible association with different charge states of a V2OH center is discussed.

• 出版日期2012-2-23