Detection of Sulfur-Related Defects in Sulfur Diffused n- and p-Type Si by DLTS
Abstract
Sulfur is diffused into Czochralski (CZ) and Float-Zone (FZ) silicon wafers at 1200 °C for 30 h. After diffusion, the wafers are slowly cooled in air. Several defect levels are observed by deep level transient spectroscopy (DLTS) in n- and p-type samples. All defects levels are related to sulfur defects, but none could be identified with the donor and double donor states of substitutional S or molecular S2. Additional annealing of the samples at 300 °C generates four DLTS levels in n-type Si and no peaks in p-type Si. The enhancement of the emission rate with the electrical field confirm their donor and double donor-like behavior. The authors identify the four DLTS levels in the annealed n-type Si samples with the different charge states of monoatomic S and molecular S2 (S0, S+, S20, and S2+) defects in Si. Hydrogenation of the annealed samples by wet chemical etching results in a reduction of the intensity of S0, S+, S20, and S2+ due to a passivation of these defects. The authors did not observe any electrically active SH-complexes in the hydrogenated samples.
- Publication:
-
Physica Status Solidi Applied Research
- Pub Date:
- September 2019
- DOI:
- 10.1002/pssa.201900303
- Bibcode:
- 2019PSSAR.21600303G