Influence of Structural Defects on Minority Carrier Lifetime in 4H-SiC Epitaxial Layers: Optical Lifetime Mapping
2009 (English)In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 105, no 12Article in journal (Refereed) Published
The influence of structural defects on the minority carrier lifetime in 4H-SiC epilayers has been studied using high spatial resolution optically detected lifetime measurements. Full wafers mappings with 200 µm spatial resolution revealed the carrier lifetime variations that can be associated with structural defects replicated from the substrate and variations in the epitaxial growth conditions due to the susceptor design. High resolution mappings over smaller regions with lateral step size down to 20 µm, revealed local carrier lifetime reductions associated with different structural defects in the epitaxial layers. Identified defects that influence the carrier lifetime are the carrot defects, different types of in-grown stacking faults. Also clusters of threading screw dislocations in the epilayer, probably originating from the dissociation of micropipe in the substrate, are found to effectively reduce the carrier lifetime. Furthermore, optically detected lifetime mapping has been demonstrated as a non-destructive technique which allows non-visible structural defects to be detected in as-grown epilayers.
Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2009. Vol. 105, no 12
National CategoryNatural Sciences
IdentifiersURN: urn:nbn:se:liu:diva-17439DOI: 10.1063/1.3147903ISI: 000267599600051OAI: oai:DiVA.org:liu-17439DiVA: diva2:209386