Structure of Carrot Defects in 4H-SiC Epilayers


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Structure of the “carrot” defects in 4H-SiC homoepitaxial layers deposited by CVD has been investigated by plan-view and cross-sectional transmission x-ray topography, cross-sectional transmission electron microscopy, atomic force microscopy, and KOH etching. The carrot defects nucleate at the substrate/epilayer interface at the emergence points of threading screw dislocations propagating from the substrate. The typical defect consists of two stacking faults: one in the prismatic plane with second one in the basal plane. The faults are connected by a stair-rod dislocation with Burgers vector 1/n[10-10] with n>3 at the cross-over. The basal plane fault is of Frank-type. Carrot defects are electrically active as evidenced by contrast in EBIC images indicating enhanced carrier recombination rate. Presence of carrot defects in the p-i-n diodes results in higher pre-breakdown reverse leakage current and approximately 50% lower breakdown voltage compared to the nominal value.



Materials Science Forum (Volumes 527-529)

Edited by:

Robert P. Devaty, David J. Larkin and Stephen E. Saddow




X. Zhang et al., "Structure of Carrot Defects in 4H-SiC Epilayers", Materials Science Forum, Vols. 527-529, pp. 327-332, 2006

Online since:

October 2006




[1] A.R. Powell and L.B. Rowland: Proc. IEEE Vol. 90 (2002), p.942.

[2] A.R. Powell, R.T. Leonard, M.F. Brady, St.G. Müller, V.F. Tsvetkov, R. Trussell, J.J. Sumakeris, H. McD. Hobgood, A.A. Burk, R.C. Glass and C.H. Carter, Jr.: Mater. Sci. Forum Vol. 457-460 (2004), p.41.


[3] P.G. Neudeck, W. Huang and M. Dudley: IEEE Trans. Electron Devices Vol. 46 (1999), p.478.

[4] Y. Wang, G.N. Ali, M.K. Mikhov, V. Vaidyanathan, B.J. Skromme, B. Raghothamachar and M. Dudley: J. Appl. Phys. Vol. 97 (2005), p.013540.

[5] T. Kimoto, Z. Chen, S. Tamura, and S. Nakamura: Jpn. J. Appl. Phys., Part I Vol. 40 (2001), p.3315.

[6] Q. Wahab, A. Ellison, A. Henry, E. Janzén, C. Hallin, J. Di Persio, and R. Martinez: Appl. Phys. Lett. Vol. 76 (2000), p.2725.

[7] T. Okada, N. Miyamoto, and H. Matsunami: IEEE Trans. Electron Devices Vol. 46 (1999), p.471.

[8] T. Okada, T. Kimoto, H. Noda, T. Ebisui, H. Matsunami, and F. Inoko: J. Appl. Phys. Vol. 41 (2002), p.6320.

[9] N. Vouroutzis, R. Yakimova, M. Syväjärvi, H. Jacobson, J. Stoemenos, and E. Janzén: Mater. Sci. Forum Vol. 389-393 (2002), 395.


[10] N. Vouroutzis, M. Syväjärvi, J. Stoemenos, and R. Yakimova: Mater. Sci. Forum Vol. 433-436 (2003), p.277.

[11] X. Zhang, S. Ha, M. Benamara, M. Skowronski, M.J. O' Loughlin and J.J. Sumakeris: Appl. Phys. Lett. Vol. 85 (2004), p.5209.

[12] S. Ha, W.M. Vetter, M. Dudley and M. Skowronski: Mater. Sci. Forum Vol. 389-393 (2002), p.443.

[13] S. Maximenko, S. Soloviev, D. Cherednichenko, and T. Sudarshan: J. Appl. Phys. Vol. 97 (2005), p.013533.

[14] S. Maximenko, S. Soloviev, D. Cherednichenko, and T. Sudarshan: Appl. Phys. Lett. Vol. 84 (2004), p.1576.

[15] M. Bhatnagar, B.J. Baliga, H.R. Kirk and G.A. Rozgonyi: IEEE Trans. Electron Devices Vol. 43 (1996), p.150.