Shallow boron, the deep D-center and their influence on carrier lifetime in n- and p-type 4H-SiC
(English)Manuscript (preprint) (Other academic)
The shallow boron and deep D-center are analyzed by minority carrier transient spectroscopy (MCTS), deep level transient spectroscopy (DLTS) and optical-electrical MCTS in n-type 4H-SiC with varying concentrations of boron, and in p-type 4H-SiC. MCTS, using high resolution correlation functions, shows the D-center to be composed of two closely overlapping peaks, referred to as D(a) and D(b), both most likely originating from the same defect located on inequivalent lattice sites. The hole capture cross sections of the D center are derived from DLTS filling pulse measurements in p-type material. The electron capture behavior of the D-center is analyzed by optical-electrical MCTS, and we find the center to be a pure hole trap, unable to act as a recombination center, with electron capture cross sections smaller than 1·10-23 cm2. The shallow boron peak is found to be composed of two or more overlapping levels in high resolution MCTS spectra. The shallow levels are further demonstrated to produce minority carrier trapping and detrapping effects in n-type 4H-SiC, which result in long time-resolved photoluminescence (TRPL) transients with microsecond decay constants, even in material containing high concentrations of the lifetime killing center Z1/2.
Condensed Matter Physics
IdentifiersURN: urn:nbn:se:liu:diva-121545OAI: oai:DiVA.org:liu-121545DiVA: diva2:856378