The combined effects of crystal growth conditions and impurity (Sb, P, B, Ga) concentration on low-angle boundary (LAB) formation in silicon single crystals growing by Czochralski technique was investigated. The dependence of LAB formation frequency and LAB parameters on crystal growth conditions and impurity content was found. I mpurity effects on LAB formation become apparent a t concentrations of about lo'* ~m -~. -All impurity investigated decreases the probability of LAB formation, the acceptor impurity influence is stronger. At B concentration exceeding 2 .