Low-temperature extended defect removal following low-energy ion implantation

Abstract

In this study, residual defects resulting from Ge+ preamorphization of Si substrates prior to low-energy (6 keV) BF+2 implantation are compared using cross-section transmission electron microscopy. Complete defect annihilation including end of range damage dislocation loops has been accomplished for samples preamorphized by 27 keV Ge+ implants at rapid thermal anneals as low as 950 °C. Resulting junction depths are less than 70 nm, at a background concentration of 1×1017 cm−3. Low-energy BF+2 implantation was also found to prevent nucleation of the F+-induced surface damage that appears following annealing of higher energy BF+2 implants into crystalline and preamorphized substrates.