Fullerene ion (C/sub 60//sup +/) implantation in GaAs[100] substrate

Fullerene ion (C/sub 60//sup +/) implantation in GaAs[100] substrates was performed to study the amount of vacancies created by carbon cluster implantation in GaAs. C/sub 60//sup +/ ions were implanted at room temperature with atomic doses from 6/spl times/10/sup 12/ atoms/cm/sup 2/ to 3/spl times/10/sup 15/ atoms/cm/sup 2/ at the energy between 60 keV (i.e. 1.0 keV per carbon atom in C/sub 60/ fullerene) and 300 keV (5.0 keV per carbon atom). C/sub 2//sup +/-implantation in GaAs was also performed at the energy of 10 keV (5.0 keV per carbon atom) with atomic doses of 2/spl times/10/sup 13/ atoms/cm/sup 2/ and 6/spl times/10/sup 14/ atoms/cm/sup 2/ to compare the generation of vacancies by C/sub 60//sup +/-implantation with that by a small carbon cluster ion-implantation. Rutherford backscattering spectrometry (RBS) analysis for GaAs[100] substrates implanted by C/sub 60//sup +/, C/sub 2//sup +/ were performed in order to study the amount of vacancies. The channeling RBS spectra showed that the vacancies created by C/sub 60//sup +/-implantation were one order of magnitude higher than by C/sub 2//sup +/-implantation. This high vacancy generation is caused by the non-linear multiple collision effect of large cluster bombardment. This result strongly indicates that C/sub 60//sup +/-implantation is highly effective for As vacancy generation.