DLTS study of oxygen precipitates in silicon annealed at high pressure

Abstract

The evolution of oxygen precipitates (OPs) created at 900–1000 K in SiCz with initial oxygen concentration 8 × 10 17 cm −3 was studied by DLTS technique. The samples were subjected to high pressure (HP) treatment up to 1.3 GPa at high temperature (HT, 1230–1550 K) which caused a partial dissolution of OP. A new way of studying the oxygen distribution is suggested. It is based on the investigation of an electrically active complex of the oxygen atom with a vacancy (A-center, level E c − 0.18 eV). A-centers were introduced by 3.0 MeV electron irradiation with dose 1 × 10 15 cm −2 and DLTS was used for A-center agglomerates detection. The analysis of data obtained allows one to conclude that the irradiation dose used does not decompose OPs. It has been found that hydrostatic pressure retards OP dissolution at HT treatment through a decrease in the migration energy E a, coefficient D o and diffusion coefficient D. The effect is explained on the assumption that oxygen diffuses in the form of connected pairs of the oxygen and self-interstitials.