Investigation of Ga ion implantation-induced damage in single-crystal 6H-SiC

In order to investigate the damage in single-crystal 6H-silicon carbide (SiC) in dependence on ion implantation dose, ion implantation experiments were performed using the focused ion beam technique. Raman spectroscopy and electron backscatter diffraction were used to characterize the 6H-SiC sample before and after ion implantation. Monte Carlo simulations were applied to verify the characterization results. Surface morphology of the implantation area was characterized by the scanning electron microscope (SEM) and atomic force microscope (AFM). The swelling effect induced by the low-dose ion implantation of 1014-1015 ions/cm² was investigated by AFM. The typical Raman bands of single-crystal 6H-SiC were analysed before and after implantation. The study revealed that the thickness of the amorphous damage layer was increased and then became saturated with increasing ion implantation dose. The critical dose threshold (2.81 × 1014-3.26 × 1014 ions/cm²) and saturated dose threshold (~5.31 × 1016 ions/cm²) for amorphization were determined. Damage formation mechanisms were discussed, and a schematic model was proposed to explain the damage formation

Determination of Compensation Ratios of Al-Implanted 4H-SiC by TCAD Modelling of TLM Measurements

The prediction of the compensation induced hole concentration reduction in implanted Al regions is a key parameter in developing high power SiC devices. Hall effect measurements are commonly used to determine the compensation ratio of Al implanted regions. Due to the fact that this measurement method is rather complex, an approximate method was developed by using transfer length method structure measurements in combination with a TCAD simulation model. The determined compensation ratios from this works simulation and from Hall effect measurements from literature show consistent compensation ratios. Based on this data a fit function was derived which allows for estimating the compensation ratio for a wide Al concentration range