Effect of ion implantation parameters on Al dopant redistribution in SiC after annealing:: Defect recovery and electrical properties of p-type layers

Epilayers of 6H and 4H-SiC were Al implanted with various doses to form p-type layers after a postimplantation annealing performed at 1700degreesC/30 min. Rutherford backscattering spectrometry in the channeling mode analyses carried out before and after annealing show virgin nonimplanted equivalent spectra if the implanted layers are not amorphized. The amorphous layers are recrystallized after annealing with a residual damage level of the lattice relative to the quantity of the dopant implanted. Secondary ion mass spectrometry measurements performed on the implanted samples before and after annealing illustrate a good superposition of the profiles obtained before and after the annealing on nonamorphized samples. Dopant redistribution occurs after annealing, only on amorphized layers, with an intensity that increases with the implanted dose. Deduced from sheet resistance measurements, the dopant activation increases with the implanted dose. Activation of 80%-90% is obtained from capacitance-voltage measurements on samples implanted with a 10(13) cm(-2) total dose. (C) 2003 American Institute of Physics.