HIGH-ENERGY NI ION-IMPLANTATION AND THERMAL ANNEALING FOR ALPHA-SIC SINGLE-CRYSTAL

The annealing behavior of alpha-SiC(0001) single crystals is studied using high energy ion implantations and thermal annealings. 1.0 MeV Ni+ ion implantations at RT were carried out on samples with fluence of 1 X 10(15) and 1 X 10(17)/CM2. Post-implantation annealings were performed in 1 atm Ar gas flow at 500, 1000 and 1500-degrees-C for 2 h. Samples were analyzed by Rutherford backscattering spectroscopy with channeling and scanning electron microscopy. During the 500-degrees-C annealing, the thickness of the introduced amorphous layer, T(A), did not change for both samples. During the 1000-degrees-C annealing, T(A) decreased for the 1 X 10(15) Ni+/CM2 Sample, but not for the 1 X 10(17) Ni+/CM2 . The initiation temperature of the recrystallization increases with the fluence. During the 1500-degrees-C annealing, an explosive recrystallization occurred for both samples. Moreover, in the recrystallized region of the 1 x 10(17) Ni+/CM2 sample, a layer with a high defect concentration was found in the depth range from 0.5 mum to 0.7 mum, but not for the 1 X 10(15) Ni+/CM2 . The recrystallization at 1500-degrees-C was accompanied by an extensive Ni diffusion. Then, the Ni profile changed from a Gaussian-like distribution to a trapezoid which extends from the surface to a depth 0.5 mum. The new Ni distribution is faced with the layer with a high defect concentration at a depth of 0.5 mum.