The electrical properties of sulphur in silicon

Abstract
Hall effect and diode C-V type measurements (including DLTS) have been used to study the several levels introduced by sulphur into the upper half of the silicon band gap. Where possible, the electron capture cross section of each level has also been measured. The results are interpreted in terms of two well characterized and reproducibly occurring centers sulphur I (0.18 and 0.38 eV) and sulphur II (0.32 and 0.53 eV). A third center, or variety of close centers, with energy levels of <0.1 eV were also found, but their occurrence was determined by the starting material and diffusion conditions. The centers sulphur I and II were both assumed to be double donors.The observed variations in concentration of sulphur I and sulphur II with diffusion temperature have enabled us to fit previously published results into a consistent pattern.