Journal of Crystal Growth, Vol.483, 134-139, 2018
Low threading dislocation density aluminum nitride on silicon carbide through the use of reduced temperature interlayers
In this work, reduced threading dislocation density AlN on (0001) 6H-SiC was realized through the use of reduced temperature AlN interlayers in the metalorganic chemical vapor deposition growth. We explored the dependence of the interlayer growth temperature on the AlN crystal quality, defect density, and surface morphology. The crystal quality was characterized using omega rocking curve scans and the threading dislocation density was determined by plan view transmission electron microscopy. The growth resulted in a threading dislocation density of 7 x 10(8) cm(-2) indicating a significant reduction in the defect density of AlN in comparison to direct growth of AlN on SiC (similar to 10(10) cm(-2)). Atomic force microscopy images demonstrated a clear step-terrace morphology that is consistent with step flow growth at high temperature. Reducing the interlayer growth temperature increased the TD inclination and thus enhanced TD-TD interactions. The TDD was decreased via fusion and annihilation reactions. (C) 2017 Elsevier B.V. All rights reserved.
Keywords:Metalorganic chemical vapor deposition (A3);Transmission electron microscopy (A1);X-ray diffraction (A1);Defect reduction (A1);Nitrides (B1)