Comparison of Post-Growth Carrier Lifetime Improvement Methods for 4H-SiC Epilayers
We compare two methods for post-growth improvement of bulk carrier lifetime in 4H-SiC: dry oxidations and implantations with either 12C or 14N, followed by high temperature anneals in Ar atmosphere. Application of these techniques to samples cut from the same wafer/epilayer yields 2- to 11-fold lifetime increases, with the implantation/annealing technique shown to give greater maximum lifetimes. The maximum lifetimes reached are ~5μs after 12C implantation at 600°C and annealing in Ar for 180 minutes at 1500°C. Higher temperatures give decreased lifetimes, a result which differs from reports in literature.
Robert P. Devaty, Michael Dudley, T. Paul Chow and Philip G. Neudeck
I.D. Booker et al., "Comparison of Post-Growth Carrier Lifetime Improvement Methods for 4H-SiC Epilayers", Materials Science Forum, Vols. 717-720, pp. 285-288, 2012