Micro-Raman and ion channeling study of crystal damage in Si induced by focused Co ion beam implantation

The lattice damage of silicon produced by ion implantation at extremely hig h current density of 0.8 A/cm(2) (2.5 x 10(18) cm(-2) s(-1)) was investigat ed. In a focused ion beam system, implantation was carried out with 70 keV Co ions, fluences of 1.2 x 10(16) cm(-2) and 6.7 x 10(15) cm(-2) into Si (1 11) at room temperature and elevated temperatures between 355 degreesC and 400 degreesC. Radiation damage measurements were performed by Rutherford ba ckscattering/channeling spectroscopy and micro-Raman analysis. The radiatio n damage was studied as a function of pixel dwell-time and implantation tem perature. The critical temperature for amorphization increases with current density. Although the fluence of the focused ion implantation was constant , crystalline layers were obtained for short and amorphous layers for long pixel dwell-times. The critical dwell-time of crystalline/amorphous transit ion increases with implantation temperature. From the results a typical rim e for defect annealing of 10(-5) s at 400 degreesC and an activation energy of (2.5 +/- 0.6) eV were deduced.