DEEP LEVELS IN HEAT-TREATED AND CF-252-IRRADIATED P-TYPE SILICON SUBSTRATES WITH DIFFERENT OXYGEN-CONTENT

The first results are presented of a deep-level transient spectroscopy (DLTS) study of deep levels in p-type silicon wafers with different o xygen contents and thermal pretreatments. The DLTs results are correla ted with those of a structural characterization using cross-sectional transmission electron microscopy (TEM). The silicon oxide precipitate density and distribution correlates with the occurrence of minority ca rrier traps in the substrate. After irradiation with the fission produ cts of a Cf-252 source, an order of magnitude increase of the leakage current is observed. At the same time, new DLTs peaks are introduced. While the creation of the divacancy-related centre (V2) is not affecte d by the presence and the status of oxygen, this is not the case for t he second dominant peak related to an interstitial carbon-interstitial oxygen complex (C(i)O(i)) in p-type Czochralski substrates. In genera l the concentration of this trap scales with the residual interstitial oxygen content.