High energy Ni ion implantation and thermal annealing for α-SiC single crystal

Abstract

The annealing behavior of α-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 × 1015 and 1 × 1017cm2. Post-implantation annealings were performed in 1 atm Ar gas flow at 500, 1000 and 1500°C for 2 h. Samples were analyzed by Rutherford backscattering spectroscopy with channeling and scanning electron microscopy.During the 500°C annealing, the thickness of the introduced amorphous layer, TA, did not change for both samples. During the 1000°C annealing, TA decreased for the 1 × 1015 Ni+cm2 sample, but not for the 1 × 1017 Ni+cm2. The initiation temperature of the recrystallization increases with the fluence. During the 1500°C annealing, an explosive recrystallization occurred for both samples. Moreover, in the recrystallized region of the 1 × 1017 Ni+cm2 sample, a layer with a high defect concentration was found in the depth range from 0.5 μm to 0.7 μm, but not for the 1 × 1015 Ni+cm2. The recrystallization at 1500°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 μm. The new Ni distribution is faced with the layer with a high defect concentration at a depth of 0.5 μm.