Dwell-time effects in focused ion beam synthesis of cobalt disilicide: reflectivity measurements

Cobalt disilicide layers were produced by 70 keV Co2+ focused ion beam impl antation into Si(111) at temperatures Of about 400 degrees C and subsequent annealing. The CoSi2 layer quality depends on pixel dwell-time and substra te temperature. Only properly chosen parameters result in a continuous laye r. The: dwell-time (1-250 mu s) and substrate temperature (355 - 400 degree s C) dependence was investigated by scanning electron microscopy, reflectiv ity measurements and Rutherford backscattering spectroscopy/channeling. The results show that the irradiation damage increases with dwell-time and dec reases with temperature. indicating an interplay between the damage creatio n I ate and the dynamic annealing rate. Already after implantation of less than a tenth part of the dose required for continuous layer formation, the quality of the resulting CoSi2 layer is predetermined. (C) 1999 Elsevier Sc ience B.V. All rights reserved.