IN-SITU LASER REFLECTOMETRY STUDY OF THE AMORPHIZATION OF SILICON-CARBIDE BY MEV ION-IMPLANTATION

In situ laser reflectometry and ex situ Rutherford backscattering spec trometry have been used to investigate the ion fluence and temperature dependence of the amorphization process in silicon carbide induced by 3 MeV I2+ irradiation. A comparative study in silicon showed that dam age accumulation in silicon carbide proceeds more gradually in the pre liminary stage of amorphization. The amorphization fluence depends wea kly on temperature below 300 K but strongly above 300 K. Silicon carbi de is amorphized more quickly than silicon at elevated temperatures. A t very low temperatures a higher ion fluence for the amorphization of silicon carbide is required in comparison to silicon. Owing to this be havior, different mechanisms of damage growth are, assumed to be prese nt in these semiconductors. A critical energy density of 5.6X10(24) eV /cm(3) for the amorphization of the silicon carbide crystal up to the surface has been found at room temperature. Experimental results are c ompared with predictions of the models proposed by Carter as well as b y Morehead and Crowder. (C) 1998 American Institute of Physics.