Abstract: Two observations and their analysis are performed in this short communication. One, the bulk defects Z1/2 and EH5 in the 4H-SiC epitaxial layers manifest themselves as SiO2/4H-SiC interface states in the MOS device fabricated on them due to their high volume density. Two, there is new evidence suggesting formation of silicon nitride at the oxide/SiC interface after nitric oxide annealing of the oxidised 4H-SiC epitaxial surface resulting in K0 defects that act as E' centres. The formation of either C-O-N bonds or N-N-N bonds at the interface keeps the fixed charge and near-interface trap density the same due to equal number of electrons in the bonds. Also, the charge correlation with Si<111>/SiO2 structure remains unaffected due to formation of either type of bonds at the SiO2/4H-SiC (0001) interface
Keywords—Defects, metal-oxide-semiconductor, Silicon Carbide, Silicon, NO annealing
[1]. Alkauskas, M.D. McCluskey, and C.G. Van de Walle, "Tutorial: Defects in semiconductors- Combining experiment and theory", J. Appl. Phys., vol. 119, 181101, 2016.
[2]. S.M. Sze, "Metal-Semiconductor Contacts" in "Physics of Semiconductor Devices", 2nd edition, Bell Laboratories, New Jersey, Wiley-Interscience publication, John-Wiley and Sons, NY, USA, 1981;245-311.
[3]. E.H. Nicollian, J.R. Brews, MOS (Metal Oxide Semiconductor) Physics and Technology, Bell Laboratories, New Jersey, Wiley-Interscience publication, John-Wiley and Sons, NY, USA, 1982.
[4]. M.A. Mannan, K.V. Nguyen, R.O. Pak, C. Oner, K.C. Mandal, "Deep levels in n-type 4H-Silicon Carbide epitaxial layers investigated by deep-level transient spectroscopy an isochronal annealing studies", IEEE Trans. on Nuclear Science, 2016;63(2):1083-1090.
[5]. M.A. Mannan, S.K. Chaudhari, K.V. Nguyen, K. C. Mandal, "Effect of Z1/2, EH5, and Ci1 deep defects on the performance of n-type 4H-SiC epitaxial layers Schottky detectors: Alpha spectroscopy and deep level transient spectroscopy studies", J. Appl. Physics, 2014;115:224504.
