Infrared reflection investigation of ion-implanted and post-implantation-annealed epitaxially grown 6H-SiC

Abstract

Multiple energy Al + and C + ions were implanted into 6H-SiC at room temperature (25°C) and elevated temperature (600°C), respectively, followed by 1550°C annealing for 30 min. Fourier transform infrared spectroscopy was used to evaluate the optical properties in the mid-infrared range. An effective medium model, taking into account the presence of an implantation-induced amorphous phase, was developed to establish the relationship between the changes of optical properties and modification of structure. Complete amorphization in the implanted layer was evidenced for room temperature implantation but no such case occurred at elevated temperature implantation. Elimination or decrease of the amorphous phase, via 1550°C annealing, was represented by the recovery of reflectance intensity and shape. Some structural and optical parameters, such as layer thickness and phonon damping constants of the amorphized SiC, were derived from fitting to measured data. Our work demonstrated the successful application of the Lorentz-Drude oscillator model in evaluating the lattice quality of the amorphous/crystalline SiC system.