Structural, optical and chemical characterization of 300°C, MeV ion implanted and 1700°C annealed 6H-SiC

ABSTRACT ABSTRACTThis work deals with the structural, optical and chemical characterization of ion implanted and annealed crystalline SiC. N+ or Al+ ions with various MeV energy and fluence values were implanted at 300°C in 6H-SiC wafers. These processes produced about 1 ?m thick doping profiles characterized by a sequence of peaks and valleys across an average plateau value. The annealing process was done in a radio frequency furnace at 1700°C for 30 min in high purity Ar atmosphere. The hot implanted layers show the presence of a weak damage amount, whose profile was estimated by confocal micro-Raman measurements. The annealed samples, in spite of a good crystal recovery, showed the formation of secondary defects as inferred by the Rutherford Back Scattering-Channeling spectrometry. The relative magnitude and position of peaks and valleys in the doping profiles were preserved by the high temperature annealing but the annealed doping profile was displaced towards the surface with respect to the as-implanted profile as shown by the Secondary Ion Mass Spectrometry measurements. No material loss but material densification due to the reordering of the crystalline structure can explain the trend of the chemical profiles.