Self-interstitials and thermal donor formation in silicon: new measurements and a model for the defects

Abstract

Silicon containing oxygen (1018 cm-3) and carbon (7*1017 cm-3) has been heated at 450 degrees C for times up to 600 h to generate thermal donors. Measurements indicate that for every two oxygen atoms that are precipitated there is generation of one self-interstitial. The latter defects are detected by means of their selective trapping by carbon. These results lead to a proposed model of a thermal donor consisting of a small oxygen agglomerate with a bonded self-interstitial. All relevant data appears to be explicable on this basis.