Correlation of end-of-range damage evolution and transient enhanced diffusion of boron in regrown silicon

Amorphization of a n-type Czochralski wafer was achieved using a series of $Si+$ implants of 30 and 120 keV, each at a dose of $1×1015 cm2.$ The $Si+$ implants produced a 2400 Å deep amorphous layer, which was then implanted with 4 keV $1×1014/cm2 B+.$ Postimplantation anneals were performed in a tube furnace at 750 °C, for times ranging from 15 min to 6 h. Secondary ion mass spectrometry was used to monitor the dopant diffusion after annealing. Transmission electron microscopy (TEM) was used to study the EOR defect evolution. Upon annealing, the boron peak showed no clustering, and TED was observed in the entire boron profile. TEM results show that both {311} defects and dislocation loops were present in the EOR damage region. The majority of the {311} defects dissolved in the interval between 15 min and 2 h. Results indicate that {311} defects release interstitials during the time that boron exhibits TED. These results show that there is a strong correlation between {311} dissolution in the EOR and TED in the regrown silicon layer. Quantitative TEM of dislocation loop growth and {311} dissolution indicates that in addition to {311} defects, submicroscopic sources of interstitials may also exist in the EOR which may contribute to TED.