Deep levels in oxygenated n-type high-resistivity FZ silicon before and after a low-temperature hydrogenation step

The behavior of oxygen in oxygen-doped high-resistivity (HR) n-type float-zone (FZ) silicon has been studied using a combination of analytical techniques. In the as-doped material, a large number of deep levels have been observed with deep-level transient spectroscopy. The corresponding parameters (concentration, activation energy, and trap signature) are given, and the possible identity is discussed in view of the presence of oxygen and other impurities in the material. In addition, the impact of a low-temperature hydrogen-plasma preannealing on the formation of oxygen thermal donors (OTDs) and other oxygen-related shallow thermal donors (STDs) at 450degreesC is described. It is shown that the introduction rate of OTDs in oxygenated HR FZ silicon is much smaller than in Czochralski silicon. In fact, for short anneals at 450degreesC following a plasma treatment, the STDs are the ones which have been predominantly created near the surface of the samples. (C) 2003 The Electrochemical Society.