Comparison of oxygen and hydrogen gettering at high-temperature postimplantation annealing of hydrogen- and helium- implanted czochralski silicon

摘要

P-type Czochralski (Cz) Si was implanted with H (180 keV, 2.7 centre dot 10~(16) cm~(-2)) or He (300 keV, centre dot 10~(16) cm~(-2)) ions. The gettering of O and H atoms by the buried implantation damage layers during annealing up to 4 hours (1000 deg in H_2 or N_2 ambient) was studied by secondary ion mass spectroscopy (SIMS) and spreading resistance probe (SRP) measurements. Buried defect layers act as good getter centers for O and H atoms at appropriate heat treatments. The enhanced gettering of O atoms in H implanted Cz Si (as compared to the gettering of O in He implanted samples) as well as the enhanced gettering of O during annealing in H_2 flow (as compared to N_2 ambient) can be explained by a hydrogen enhanced O diffusion towards the defect layers. According to a strong accumulation of O at the buried damage layers and near the surface some anomalies of the SRP profiles can be observed after post-implantation annealing.