SURFACE-ROUGHNESS IN CU(100) [CO/CU](N) SYSTEMS GROWN BY ION-BEAM SPUTTERING/

The development of surface roughness in Co/Cu systems was investigated through the use in situ scanning tunneling microscopy. Multilayers an d single layers of cobalt and copper were sequentially grown on a Cu(1 00) substrate. We show that the growth mode of cobalt on copper is qui te different from that of copper on cobalt. We characterize these diff erences by looking at the lateral variations and obtaining a mean meas ure of island length. The cobalt tends to nucleate in small (<5 nm) is lands. An overlayer of copper broadens this length scale while maintai ning approximately the same peak-to-peak roughness of 5 monolayers. Th ese growth mechanisms are shown to affect the way in which roughness p ropagates through multilayers. The impact of deposition temperature is also examined and seen to alter the degree of roughness in these samp les. We conclude by discussing the implications for the magnetoresista nce of these structures. (C) 1996 American Institute of Physics.