Carrier lifetime investigation in 4H-SiC grown by CVD and sublimation epitaxy
2001 (English)In: Materials Science in Semiconductor Processing, ISSN 1369-8001, Vol. 4, no 03-jan, 191-194 p.Article in journal (Refereed) Published
Depth-resolved carrier lifetime measurements were performed in low-doped epitaxial layers of 4H silicon carbide samples. The technique used was a pump-and-probe technique where carriers are excited by an above-bandgap laser pulse and probed by free carrier absorption. Results from chemical vapour deposition samples show that lifetimes as high as 2 mus may be observed in the mid-region of 40 mum thick epilayers. For epilayers grown by the sublimation method decay transients were characterised by a fast (few nanoseconds) initial recombination, tentatively assigned to the 'true' lifetime, whereas a slow tail of several hundred microsecond decay time was assigned to trapping centres. From the saturation of this level at increased pumping we could derive the trapping concentration and their depth distribution peaking at the epilayer/substrate interface.
Place, publisher, year, edition, pages
2001. Vol. 4, no 03-jan, 191-194 p.
carrier lifetime, SiC, pump-probe technique, trapping
IdentifiersURN: urn:nbn:se:kth:diva-20482ISI: 000167727200044OAI: oai:DiVA.org:kth-20482DiVA: diva2:339177
QC 201005252010-08-102010-08-10Bibliographically approved