Lifetime Enhancement of 4H-SiC PiN Diodes Using High Temperature Oxidation Treatment


Article Preview

In this paper, the application of a high temperature thermal oxidation and annealing process to 4H-SiC PiN diodes with 35 μm thick drift regions is explored, the aim of which was to increase the carrier lifetime in the 4H-SiC. Diodes were fabricated using 4H-SiC material and underwent a thermal oxidation in dry pure O2 at 1550C followed by an argon anneal at the same temperature. Reverse recovery tests indicated a carrier lifetime increase of around 42% which is due to increase of excessive minority carriers in the drift region. The switching results illustrate that the use of this process is a highly effective and efficient way of enhancing the electrical characteristics of high voltage 4H-SiC bipolar devices.



Edited by:

Robert Stahlbush, Philip Neudeck, Anup Bhalla, Robert P. Devaty, Michael Dudley and Aivars Lelis




Y. Bonyadi et al., "Lifetime Enhancement of 4H-SiC PiN Diodes Using High Temperature Oxidation Treatment", Materials Science Forum, Vol. 924, pp. 440-443, 2018

Online since:

June 2018




* - Corresponding Author

[1] K. Danno et al., Investigation of carrier lifetime in 4H-SiC epilayers and lifetime control by electron irradiation,, Appl. Phys. Lett. 90, 202109, (2010).


[2] T. Tawara et al., Evaluation of Free Carrier Lifetime and Deep Levels of the Thick 4H-SiC Epilayers,, Materials Science Forum, Vols. 457-460, pp.565-568, (2004).


[3] P. B. Klein et al., Lifetime-limiting defects in n−n− 4H-SiC epilayers,, Appl. Phys. Lett. 88, 052110, (2006).

[4] K. Kawahara, J. Suda, and T. Kimoto, Elimination of deep levels in thick SiC epilayers by thermal oxidation and proposal of the analytical model,, Mater. Sci. Forum, vol. 717–720, p.241–246, Feb. (2012).


[5] Y. Bonyadi, P. M. Gammon, R. Bonyadi, V. A. Shah, C.A. Fisher, D. M. Martin, P. A. Mawby, Characterization of 4H-SiC PiN Diodes Formed on Defects Identified by PL Imaging,, Materials Science Forum, Vol. 858, pp.405-409, (2016).


[6] Y. Bonyadi, P. M. Gammon, R. Bonyadi, O. Alatise, J. Hu, S. Hindmarsh, P. A. Mawby, The impact of Triangular Defects on Electrical Characteristics and Switching Performance of 3.3kV 4H-SiC PiN Diode,, 2016 IEEE Energy Conversion Congress and Exposition (ECCE), Milwaukee, WI, pp.1-5, (2016).