Effects of Nitrogen Doping on Basal Plane Dislocation Reduction in 8° Off-Cut 4H-SiC Epilayers

Abstract:

The effectiveness of an in-situ growth interrupt in nitrogen doped 8° off-cut epilayers was investigated using ultraviolet photoluminescence imaging. Low-doped n-type epilayers (<1016 cm-3) exhibited an abrupt increase in BPD to TED conversion at the growth interrupt and achieved 96-99% conversion overall (< 10 BPDs/cm-2), while high-doped epilayers had minimal conversion at the interrupt (< 1%) and overall (< 30%). This large discrepancy suggests nitrogen prohibits or alters the conversion mechanism at the growth interrupt. Therefore, a novel SEM technique was developed to "freeze-in" the interface morphology and help elucidate the conversion mechanism. Preliminary results suggest that preferential etching at the point of BPD intersection with the surface is greatly reduced in highly doped layers, which inhibits the conversion mechanism.

• Periodical: Materials Science Forum (Volumes 679-680)
• Pages: 63-66
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.679-680.63
• Online since: March 2011
• Authors: Virginia D. Wheeler, Brenda L. VanMil, Rachael L. Myers-Ward, S. Chung, Yoosuf N. Picard, Marek Skowronski, Robert E. Stahlbush, Nadeemullah A. Mahadik, Charles R. Eddy, D. Kurt Gaskill
• Keywords: 4H-SiC, Basal Plane Dislocation (BPD), Extended Defect, Nitrogen Doping, Scanning Electron Microscope (SEM), Ultra-Violet Photoluminescence

References

[1] T. Ohno, H. Yamaguchi, S. Kuroda, K. Kojima, T. Suzuki and K. Arai: J. Cryst. Growth Vol. 260 (2004), p.209.

[2] J.P. Bergman, H. Lendenmann, P.A. Nilsson and P. Skytt: Mat. Sci. For. Vol. 353-356 (2001), p.299.

[3] J.J. Sumakeris, J.P. Bergman, M.K. Das, C. Hallin, B.A. Hull, E. Janzen, H. Lendenmann, M.J. O'Loughlin, M.J. Paisley, S. Ha, M. Skowronski, J.W. Palmour, and C.H. Carter Jr: Mat. Sci. Forum Vol. 527-529 (2006), p.141.

DOI: 10.4028/www.scientific.net/msf.527-529.141

[4] B.L. VanMil, K.K. Lew, R.L. Myers-Ward, R.T. Holm, D.K. Gaskill, C.R. Eddy Jr., L. Wang and P. Zhao: J. Cryst. Growth Vol. 311 (2009), p.238.

DOI: 10.1016/j.jcrysgro.2008.11.030

[5] R.E. Stahlbush, B.L. VanMil, R.L. Myers-Ward, K.K. Lew, D.K. Gaskill, and C.R. Eddy Jr.: Appl. Phys. Lett Vol. 94 (2009) 041916.

DOI: 10.1063/1.3070530

[6] R.L. Myers-Ward, B.L. VanMil, R.E. Stahlbush, S.L. Katz, J.M. McCrate, S. A. Kitt, C.R. Eddy, Jr. and D.K. Gaskill: Mater. Sci. Forum Vol. 615-617 (2009), 105-108.

DOI: 10.4028/www.scientific.net/msf.615-617.105

[7] Z. Zhang and T.S. Sudarshan: Mat. Sci. Forum Vol. 527-529 (2006), p.243.