High-carbon concentrations at the silicon dioxide-silicon carbide interface identified by electron energy loss spectroscopy
2000 (English)In: Applied Physics Letters, ISSN 0003-6951, Vol. 77, no 14, 2186-2188 p.Article in journal (Refereed) Published
High carbon concentrations at distinct regions at thermally-grown SiO2/6H-SiC(0001) interfaces have been detected by electron energy loss spectroscopy (EELS). The thickness of these C-rich regions is estimated to be 10-15 Angstrom. The oxides were grown on n-type 6H-SiC at 1100 degrees C in a wet O-2 ambient for 4 h immediately after cleaning the substrates with the complete RCA process. In contrast, C-rich regions were not detected from EELS analyses of thermally grown SiO2/Si interfaces nor of chemical vapor deposition deposited SiO2/SiC interfaces. Silicon-rich layers within the SiC substrate adjacent to the thermally grown SiO2/SiC interface were also evident. The interface state density D-it in metal-oxide-SiC diodes (with thermally grown SiO2) was approximately 9x10(11) cm(-2) eV(-1) at E- E-v=2.0 eV, which compares well with reported values for SiC metal-oxide-semiconductor (MOS) diodes that have not received a postoxidation anneal. The C-rich regions and the change in SiC stoichiometry may be associated with the higher than desirable D-it's and the low channel mobilities in SiC-based MOS field effect transistors. (C) 2000 American Institute of Physics. [S0003-6951(00)01940-9].
Place, publisher, year, edition, pages
2000. Vol. 77, no 14, 2186-2188 p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-49586OAI: oai:DiVA.org:liu-49586DiVA: diva2:270482