NiCo silicide films have been fabricated from $300{AA}-thick;Ni_{1-x}Co_{x}(x=0.1sim0.9)$ on Si-substrates by varying RTA(rapid thermal annealing) temperatures from $700^{circ}C;to;1100^{circ}C$ for 40 sec. Sheet resistance, cross-sectional microstructure, and chemical composition evolution were measured by a four point probe, a transmission electron microscope(TEM), and an Auger depth profilemeter, respectively. For silicides of the all composition and temperatures except for $80\%$ of the Ni composition, we observed small sheet resistance of sub- $7;{Omega}/sq.,$ which was stable even at $1100^{circ}C$. We report that our newly proposed NiCo silicides may obtain sub 50 nm-thick films by tunning the nickel composition and silicidation temperature. New NiCo silicides from NiCo-alloys may be more appropriate for sub-0.1${mu}m$ CMOS process, compared to conventional single phase or stacked composit silicides.