5 - nm -thick TaSiC amorphous films stable up to 750°C as a diffusion barrier for copper metallization

Abstract

Ultrathin TaSiC amorphous films prepared by magnetron cosputtering using TaSi 2 and C targets on Si͑100͒, in a sandwiched scheme Si͑100͒ / TaSiC͑5 nm͒ / Cu, were evaluated for barrier performance in copper metallization. Optimizing carbon content maximizes thermal stability of the films as depicted by sheet-resistance, x-ray diffraction, and transmission electron microscopy examination. The stability temperatures of 700°C ͑24 at. % C͒ and 750°C ͑34 at. % C͒ have been systematically verified and discussed. Since Ta, Si, and C are compatible with integrated circuit ͑IC͒ processing, the TaSiC films are readily applicable for sub-65-nm IC production.

1-nm-thick graphene tri-layer as the ultimate copper diffusion barrier

“…The development of alternative barriers has been reported in the literature, such as atomic-layer-deposited Co(W), 6 TaSiC, 7 and WGeN, 8 self-forming barriers such as CuMn, 9,10 CuAl 11 alloys, Cu seedless Ru-based barriers, 12,13 and Cu capping materials such as CoWP. 14,15 Although these materials have demonstrated excellent Cu barrier function at thicknesses of a few nm, none can meet the sub-2-nm requirements.…”

Investigation of amorphous Ni–Al–N film as diffusion barrier between Cu and SiO2

“…It is reported that the four-probe method of sheet resistance is more reliable to characterize barrier performance than X-ray diffraction measurement since the sheet resistance is very sensitive to a tiny change of the microstructure of a sample [11]. The defects of the sample, such as atomic vacancies, and grain boundaries, can induce strong electron scatterings, which impact the resistance of the sample.…”

Low-Resistivity Ru-Ta-C Barriers for Cu Interconnects

“…In our previous results, the failure temperature was at least 750°C for 1 min for 5-nm-thick barriers of Ru 77 Ta 15 C 7 and Ta 34 Si 47 C 18 . 10,11 The barrier performance of Ta 34 Si 47 C 18 mostly arises from its amorphous nature, and amorphous Ta 34-Si 47 C 18 is thermally stable up to 800°C for 30 min. On the other hand, the as-deposited Ru 77 Ta 15 C 7 film contained nanocrystallites of Ru 4 Ta phase.…”