Solid-State Electronics, Vol.52, No.1, 140-145, 2008
Ultra-low resistivity Al+ implanted 4H-SiC obtained by microwave annealing and a protective graphite cap
In this work, we have employed a graphite cap for rapid microwave annealing of aluminum implanted 4H-SiC, in the temperature range of 1750-1900 degrees C, for 30 s durations. The graphite cap prevailed even for 1900 degrees C/30 s microwave annealing yielding a low surface roughness of 2.4 nm. Rutherford backscattering-channeling spectra indicated that 1900 degrees C microwave annealing is much more effective than 1800 degrees C/5 min conventional furnace annealing in not only alleviating the implantation-induced lattice damage but also in removing some of the defects introduced during growth of the 4H-SiC epi-layer used for the Al+ implantation. Van der Pauw-Hall measurements indicated an extremely low sheet resistance of 2.8 k Omega/square for the 1900 degrees C/30 s annealing, which is about 5 times smaller than the sheet resistance measured on the 1800 degrees C/5 min conventional furnace annealed material. (C) 2007 Elsevier Ltd. All rights reserved.
Keywords:silicon carbide;microwave annealing;graphite cap;sheet resistance;surface roughness;lattice quality