Defects in Quenched Silicon

Floating‐zone refined and pulled Si crystals doped with 10 15 B atoms/cm 3 were quenched from 800 to 1150°C into liquid nitrogen or water. As many as 10 15 donors/cm 3 were created by both types of quench. No evidence was obtained, either from electrical conductivity or from photoconductivity measurements, that single vacancies, divacancies, or vacancy‐oxygen pairs were retained by the quenches. Approximately 50% of the quenched‐in defects annealed out near 300°K with a migration energy of (0.81 ± 0.04) eV. An energy level 0.4 eV from the top of the valence band was associated with these defects.