Capacitance transient study of the metastable M center in n-type 4H-SiC.
2005 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 72, no 8Article in journal (Refereed) Published
The metastable M center in n-type 4H silicon carbide is studied in detail after it has been introduced by 2.5 MeV proton irradiation with a fluence of 1x10(12) cm(-2). The experimental procedures included deep-level transient spectroscopy, carrier capture coefficient and capacitance versus temperature measurements, and pulse-train measurements. The pulse-train measurements are reproduced by simulations. Three band-gap levels have previously been assigned to the M center: M-1 at E-C-0.42 eV, M-2 at E-C-0.63 eV, and M-3 at E-C-0.83 eV, where E-C is the conduction-band edge. Direct measurements of the majority-carrier capture cross sections show that the cross section values extracted from Arrhenius plots are about two orders of magnitude too large, indicating a large entropy factor. A detailed configuration diagram of the M center is presented, including charge state levels and reconfiguration barriers. Evidence in support of a fourth M center level, not explicitly observed, is presented. Isochronal and isothermal annealing experiments show that the M center anneal out between 310 and 370 degrees C in a process displaying first-order kinetics. The annealing process, which is shown to have an activation energy of 2.0 eV, is identified as dissociation.
Place, publisher, year, edition, pages
2005. Vol. 72, no 8
deep-level defects, 4h silicon-carbide, nitrogen participation, spectroscopy, emission, traps
Other Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:kth:diva-15007DOI: 10.1103/PhysRevB.72.085208ISI: 000231564600067ScopusID: 2-s2.0-33644963423OAI: oai:DiVA.org:kth-15007DiVA: diva2:333048
QC 201005252010-08-052010-08-052010-10-28Bibliographically approved