FORMATION AND CHARACTERIZATION OF SI COSI2,/SI EPITAXIAL HETEROSTRUCTURES/

Si/CoSi2/Si heterostructures have been fabricated by sequentially depo siting, in high vacuum, Co and Si onto (001)Si substrate. The growth o f an epitaxial CoSi2 layer has been achieved by keeping the Si substra te at 600 degrees C during Co deposition. The Si overlayer has been su ccessively obtained by deposition under different experimental conditi ons. Elevated substrate temperature has given rise to an epitaxial ove rlayer, but the high adatom mobility has led to a non-uniform coverage . A more uniform layer has been obtained by room-temperature depositio n. The as-deposited amorphous layer has been subsequently crystallized by thermal treatments preserving its uniformity, but the process resu lted in a highly defective Si overlayer. Furthermore, a preliminary st udy on the ion-beam-assisted deposition of Si onto CoSi2/Si heteroepit axial structures has been performed.