Deep Level Transient Spectroscopy of Ultra Shallow Junctions in Si Formed by Implantation
We have carried out DLTS in highly doped p+n Ultra Shallow Junctions (USJ) in Si formed by ion implantation. The samples were implanted either with a 10keV or a 5keV B implant at a dose of 5*1015cm15. The 10keV sample was also implanted with P and the 5keV samples were implanted with P and increasing doses of As to simulate an USJ in an n-well. Due to the high P and/or As implant doses, it was observed that a band offset also exists between the n-type implanted region and the n-type starting material. Therefore these samples contain another depletion region apart from the expected p+n depletion region. However, the electric fields in these regions act in opposite directions assisting the profiling of different regions after careful selection of biasing conditions. A deep state is observed in the n-type region at EC-0.34eV which has a complex Laplace DLTS signature, which has arisen due to the implantation process.
A. Cavallini, H. Richter, M. Kittler and S. Pizzini
N. Mitromara et al., "Deep Level Transient Spectroscopy of Ultra Shallow Junctions in Si Formed by Implantation", Solid State Phenomena, Vols. 131-133, pp. 497-502, 2008